I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

Supposedly, and I believe the person who told me the story because I
know him very well, a pump gasoline inside the gas tank went bad on
it. A while ago, tank was disconnected and we put it back when we got
the truck.

Truck sat outside for 2 years without any further work.

We bought a new pump from NAPA.

The truck cranks, but would not start without fuel added to carb.

If I remove the nut holding the line near the carb, then gas pours out
of it when the pump in the gas tank is activated. So, gas gets to the
carburetor.

If I pour gasoline in the carburetor, the engine starts great. It
also runs great when the engine runs and I continuously add a small
stream of gas to the carb.

However, without that stream, it does not get any gas.

There are two electric valves in the carb. If my guy cranks the motor
and presses the gas pedal, I see some drops of gasoline, but not
nearly enough for this Chevy 454 engine.

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

(...)

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

Yup. But first, remove the contaminated gasoline
from the tank, pump and lines. Safest would be
to remove the gas tank and have it de-rusted,
cleaned and lined.

--Winston

On 2012-02-14, Winston wrote:
Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

(...)

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

Yup. But first, remove the contaminated gasoline
from the tank, pump and lines. Safest would be
to remove the gas tank and have it de-rusted,
cleaned and lined.

--Winston

We did this, thanks.

i

On 2/14/2012 5:10 PM, Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.
....
Truck sat outside for 2 years without any further work.
....
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

After two years of setting dry and unattended, I'd guess the carb float
is at best stuck and other issues as well. I'm thinking these would
still have a manual accelerator pump as well.

All in all, a good carb cleaning and perhaps a kit are likely called for...

--

"Ignoramus10095" wrote in message
...
I have a Chevy Kodiak dump truck that I am trying to fix. ...
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

Clogged bronze filter at the carb gas line inlet?

jsw

On 2012-02-15, Jim Wilkins wrote:

"Ignoramus10095" wrote in message
...
I have a Chevy Kodiak dump truck that I am trying to fix. ...
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

Clogged bronze filter at the carb gas line inlet?


Jim, where is the filter that you have in mind? On the carb itself?

Like I said, I did disconnect the gas line where it enters the carb,
and fuel came out of the disconnected line when the fuel pump is
activated.

So, if you mean a clogged filter in the carburetor, I guess it is
possible, but if you mean some inline filter on the lines leading to
the carburetor, I do not think that it is possible.

i
i

"Ignoramus10095" wrote in message
...
On 2012-02-14, Winston wrote:
Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

(...)

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

Yup. But first, remove the contaminated gasoline
from the tank, pump and lines. Safest would be
to remove the gas tank and have it de-rusted,
cleaned and lined.

--Winston

We did this, thanks.

i

Onboard computer bad ?
Check fuel line pressure ?

Looks like throttle body injection (TBI), lots of stuff to go wrong.

Best Regards
Tom.
--
http://fija.org/

azotic wrote:

"Ignoramus10095" wrote in message
...
On 2012-02-14, Winston wrote:
Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

(...)

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

Yup. But first, remove the contaminated gasoline
from the tank, pump and lines. Safest would be
to remove the gas tank and have it de-rusted,
cleaned and lined.

--Winston

We did this, thanks.

i

Onboard computer bad ?
Check fuel line pressure ?

Looks like throttle body injection (TBI), lots of stuff to go wrong.

Best Regards
Tom.
--
http://fija.org/

Yes, if it is TBI it does not have a carburetor, it has a throttle body
which only superficially looks like a carb. The TBI setup has an in-tank
high(er) pressure fuel pump and two fuel injectors in the throttle body.
You can check to see if the injectors are being opened by the PCM with
"NOID" lights which you can usually borrow from an auto parts place
(with deposit). If the injectors are getting driven by the PCM they may
well be clogged/stuck, I don't believe a set of those injectors is all
that expensive. If they are not getting driven by the PCM there could be
issues with sensors like crankshaft or camshaft position.

What model year is it? I had a 1990 FS Blazer with the TBI 350 and the
TBI 454 was an option. I *think* I still have the manuals for it around.

On 2012-02-15, dpb wrote:
On 2/14/2012 5:10 PM, Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.
...
Truck sat outside for 2 years without any further work.
...
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

After two years of setting dry and unattended, I'd guess the carb float
is at best stuck and other issues as well. I'm thinking these would
still have a manual accelerator pump as well.

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however, have
those electric valves on top. It might have a bowl, but its location
is not obvious or visible.

All in all, a good carb cleaning and perhaps a kit are likely called for...

OK... will do ...

i

On 2012-02-15, Pete C. wrote:

azotic wrote:

"Ignoramus10095" wrote in message
...
On 2012-02-14, Winston wrote:
Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

(...)

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

Yup. But first, remove the contaminated gasoline
from the tank, pump and lines. Safest would be
to remove the gas tank and have it de-rusted,
cleaned and lined.

--Winston

We did this, thanks.

i

Onboard computer bad ?
Check fuel line pressure ?

Looks like throttle body injection (TBI), lots of stuff to go wrong.

Best Regards
Tom.

Yes, if it is TBI it does not have a carburetor, it has a throttle body
which only superficially looks like a carb. The TBI setup has an in-tank
high(er) pressure fuel pump and two fuel injectors in the throttle body.
You can check to see if the injectors are being opened by the PCM with
"NOID" lights which you can usually borrow from an auto parts place
(with deposit). If the injectors are getting driven by the PCM they may
well be clogged/stuck, I don't believe a set of those injectors is all
that expensive. If they are not getting driven by the PCM there could be
issues with sensors like crankshaft or camshaft position.

What model year is it? I had a 1990 FS Blazer with the TBI 350 and the
TBI 454 was an option. I *think* I still have the manuals for it around.

This does seem to be TBI (not that I know much) and the engine is a
Chevy 454!

If you have anything on it, I would love to get a copy or a scan!

Thanks a lot!


i

azotic wrote:

"Ignoramus10095" wrote in message
...
On 2012-02-14, Winston wrote:
Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

(...)

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

Yup. But first, remove the contaminated gasoline
from the tank, pump and lines. Safest would be
to remove the gas tank and have it de-rusted,
cleaned and lined.

--Winston

We did this, thanks.

i

Onboard computer bad ?
Check fuel line pressure ?

Looks like throttle body injection (TBI), lots of stuff to go wrong.

This is what the TBI unit looks like on the 1990 vintage 7.4/454:

http://wpnet.us/220_TBI.jpg

Ignoramus10095 wrote:

On 2012-02-15, dpb wrote:
On 2/14/2012 5:10 PM, Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.
...
Truck sat outside for 2 years without any further work.
...
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

After two years of setting dry and unattended, I'd guess the carb float
is at best stuck and other issues as well. I'm thinking these would
still have a manual accelerator pump as well.

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however, have
those electric valves on top. It might have a bowl, but its location
is not obvious or visible.

Almost certainly it is the TBI - Throttle Body Injection - early fuel
injection setup.

Looks like this:

http://wpnet.us/220_TBI.jpg

"Jim Wilkins" wrote in message ...

"Ignoramus10095" wrote in message
...
I have a Chevy Kodiak dump truck that I am trying to fix. ...
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

Clogged bronze filter at the carb gas line inlet?



My thoughts exactly.

http://tinyurl.com/6nlv6ra

Ignoramus10095 wrote:

On 2012-02-15, Pete C. wrote:

azotic wrote:

"Ignoramus10095" wrote in message
...
On 2012-02-14, Winston wrote:
Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

(...)

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

Yup. But first, remove the contaminated gasoline
from the tank, pump and lines. Safest would be
to remove the gas tank and have it de-rusted,
cleaned and lined.

--Winston

We did this, thanks.

i

Onboard computer bad ?
Check fuel line pressure ?

Looks like throttle body injection (TBI), lots of stuff to go wrong.

Best Regards
Tom.

Yes, if it is TBI it does not have a carburetor, it has a throttle body
which only superficially looks like a carb. The TBI setup has an in-tank
high(er) pressure fuel pump and two fuel injectors in the throttle body.
You can check to see if the injectors are being opened by the PCM with
"NOID" lights which you can usually borrow from an auto parts place
(with deposit). If the injectors are getting driven by the PCM they may
well be clogged/stuck, I don't believe a set of those injectors is all
that expensive. If they are not getting driven by the PCM there could be
issues with sensors like crankshaft or camshaft position.

What model year is it? I had a 1990 FS Blazer with the TBI 350 and the
TBI 454 was an option. I *think* I still have the manuals for it around.

This does seem to be TBI (not that I know much) and the engine is a
Chevy 454!

If you have anything on it, I would love to get a copy or a scan!

Thanks a lot!

i

http://wpnet.us/TBI_Fuel_Control.pdf

Sorry it's not in order, my scanner has ADF but no provisions for double
sided.

On Feb 14, 5:10*pm, Ignoramus10095 ignoramus10...@NOSPAM.
10095.invalid wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

Supposedly, and I believe the person who told me the story because I
know him very well, a pump gasoline inside the gas tank went bad *on
it. A while ago, tank was disconnected and we put it back when we got
the truck.

Truck sat outside for 2 years without any further work.

We bought a new pump from NAPA.

The truck cranks, but would not start without fuel added to carb.

If I remove the nut holding the line near the carb, then gas pours out
of it when the pump in the gas tank is activated. So, gas gets to the
carburetor.

If I pour gasoline in the carburetor, the engine starts great. *It
also runs great when the engine runs and I continuously add a small
stream of gas to the carb.

However, without that stream, it does not get any gas.

There are two electric valves in the carb. If my guy cranks the motor
and presses the gas pedal, I see some drops of gasoline, but not
nearly enough *for this Chevy 454 engine.

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

Start with something easy - check the ECM fuse.

On 2012-02-15, PrecisionmachinisT wrote:

"Jim Wilkins" wrote in message ...

"Ignoramus10095" wrote in message
...
I have a Chevy Kodiak dump truck that I am trying to fix. ...
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

Clogged bronze filter at the carb gas line inlet?



My thoughts exactly.

http://tinyurl.com/6nlv6ra



This link is wrong.

i

On 2/14/2012 7:14 PM, Ignoramus10095 wrote:
....

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however, have
those electric valves on top. It might have a bowl, but its location
is not obvious or visible.
....

I hadn't looked at the closeup pictures before, but just did after
thinking about the year. It's one of the hybrid injection systems.
I've had a couple but never had to work on one so forget the earlier
thoughts posted--they're not pertinent to these.

I think the phrase is "throttle body injection" for looking for information.

If I were to hazard a complete guess, it would be after two years idle
the injectors are plugged. How to attack them, specifically, I don't
know, sorry.

--

"Ignoramus10095" wrote in message
...
On 2012-02-15, PrecisionmachinisT wrote:

"Jim Wilkins" wrote in message
...

"Ignoramus10095" wrote in message
...
I have a Chevy Kodiak dump truck that I am trying to fix. ...
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

Clogged bronze filter at the carb gas line inlet?



My thoughts exactly.

http://tinyurl.com/6nlv6ra



This link is wrong.



http://tinyurl.com/7fm3me9

--

"Ignoramus10095" wrote in message
...
On 2012-02-15, PrecisionmachinisT wrote:

"Jim Wilkins" wrote in message
...

"Ignoramus10095" wrote in message
...
I have a Chevy Kodiak dump truck that I am trying to fix. ...
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

Clogged bronze filter at the carb gas line inlet?



My thoughts exactly.

http://tinyurl.com/6nlv6ra



This link is wrong.


Ignore it...

--what you have in the picture there is throttle body fuel injection and not
a carburetor.

http://en.wikipedia.org/wiki/Fuel_in...oint_injection

On Tue, 14 Feb 2012 17:10:19 -0600, Ignoramus10095
wrote:

I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

Supposedly, and I believe the person who told me the story because I
know him very well, a pump gasoline inside the gas tank went bad on
it. A while ago, tank was disconnected and we put it back when we got
the truck.

Truck sat outside for 2 years without any further work.

We bought a new pump from NAPA.

The truck cranks, but would not start without fuel added to carb.

If I remove the nut holding the line near the carb, then gas pours out
of it when the pump in the gas tank is activated. So, gas gets to the
carburetor.

If I pour gasoline in the carburetor, the engine starts great. It
also runs great when the engine runs and I continuously add a small
stream of gas to the carb.

However, without that stream, it does not get any gas.

There are two electric valves in the carb. If my guy cranks the motor
and presses the gas pedal, I see some drops of gasoline, but not
nearly enough for this Chevy 454 engine.

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i
.. Except it is not a carb. You have a TBI engine - throttle body
injected. What year is the puppy? If it is pre-1996 a good code
scanner can tell you everything you need to know, if you know what you
need to know - if you know what I mean.

The two "solenoids" are fuel injectors - and the other part - the
metal hat with the adjuster screw in it is the fuel pressure
regulator. See if the connection to one injector has 12 volts on one
side any time the key is on and it a 12 volt lamp (test light, noid
light, or 194 side marker lamp in socket) connected across the
connector flashes when the engine is turned over. If you have 12 volts
and the light flashes the injectors or regulator are likely the
problem. If not, you have electrical problems. Ther will be a "shrader
valve" somewhere on the fuel line. You need to verify your fuel
pressure. It should be roughly 10-12 PSI if my memory serves
correctly.

If it is pre 1996 you can get the trouble codes off the check engine
light by shorting terminal A to B on the aldl connector. That's the
two end terminals of the top row on the right side.

You should get a code 12 - flash - - flash flash.

Look for a code 33 or 34 (map sensor), 54 (fuel pump circuit) 55 (bad
ECM) 21 or 22 (throttle position switch), or 14 or 15 (intake air temp
sensor) Any other codes should not prevent it from starting. Also be
sure you ARE getting spark. No spark usually means no trigger for the
injectors as well.

A somple injector function test is a stethoscope - you should hear
them go "tick-tick" when the engine is cranked.

On Tue, 14 Feb 2012 16:50:34 -0800, "azotic"
wrote:


"Ignoramus10095" wrote in message
m...
On 2012-02-14, Winston wrote:
Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

(...)

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

Yup. But first, remove the contaminated gasoline
from the tank, pump and lines. Safest would be
to remove the gas tank and have it de-rusted,
cleaned and lined.

--Winston

We did this, thanks.

i

Onboard computer bad ?
Check fuel line pressure ?

Looks like throttle body injection (TBI), lots of stuff to go wrong.

Best Regards
Tom.
A lot less to go wrong than on a port injected engine though.

On Tue, 14 Feb 2012 18:27:41 -0600, dpb wrote:

On 2/14/2012 5:10 PM, Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.
...
Truck sat outside for 2 years without any further work.
...
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

After two years of setting dry and unattended, I'd guess the carb float
is at best stuck and other issues as well. I'm thinking these would
still have a manual accelerator pump as well.

All in all, a good carb cleaning and perhaps a kit are likely called for...
Except if you look at the pictures it has no carb - so no float, and
no accellerator pump.

On Tue, 14 Feb 2012 19:27:50 -0500, "Jim Wilkins"
wrote:


"Ignoramus10095" wrote in message
m...
I have a Chevy Kodiak dump truck that I am trying to fix. ...
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

Clogged bronze filter at the carb gas line inlet?

jsw

Except it has no carb.

On Tue, 14 Feb 2012 18:49:17 -0600, Ignoramus10095
wrote:

On 2012-02-15, Jim Wilkins wrote:

"Ignoramus10095" wrote in message
...
I have a Chevy Kodiak dump truck that I am trying to fix. ...
Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

Clogged bronze filter at the carb gas line inlet?


Jim, where is the filter that you have in mind? On the carb itself?

Like I said, I did disconnect the gas line where it enters the carb,
and fuel came out of the disconnected line when the fuel pump is
activated.

So, if you mean a clogged filter in the carburetor, I guess it is
possible, but if you mean some inline filter on the lines leading to
the carburetor, I do not think that it is possible.

i
i
You don't have a carb.

On 2012-02-15, dpb wrote:
On 2/14/2012 7:14 PM, Ignoramus10095 wrote:
...

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however, have
those electric valves on top. It might have a bowl, but its location
is not obvious or visible.
...

I hadn't looked at the closeup pictures before, but just did after
thinking about the year. It's one of the hybrid injection systems.
I've had a couple but never had to work on one so forget the earlier
thoughts posted--they're not pertinent to these.

I think the phrase is "throttle body injection" for looking for information.

If I were to hazard a complete guess, it would be after two years idle
the injectors are plugged. How to attack them, specifically, I don't
know, sorry.

--

How do they work, do they create pressure, or are they just valves,
with the pressure created by the in-tank pump?

i

Ignoramus10095 wrote:

On 2012-02-15, dpb wrote:
On 2/14/2012 7:14 PM, Ignoramus10095 wrote:
...

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however, have
those electric valves on top. It might have a bowl, but its location
is not obvious or visible.
...

I hadn't looked at the closeup pictures before, but just did after
thinking about the year. It's one of the hybrid injection systems.
I've had a couple but never had to work on one so forget the earlier
thoughts posted--they're not pertinent to these.

I think the phrase is "throttle body injection" for looking for information.

If I were to hazard a complete guess, it would be after two years idle
the injectors are plugged. How to attack them, specifically, I don't
know, sorry.

--

How do they work, do they create pressure, or are they just valves,
with the pressure created by the in-tank pump?

i

A fuel injector is just a solenoid actuated spray nozzle. The in-tank
pump provides the fuel pressure and the pressure regulator regulates
that pressure sending excess fuel back to the tank via the return line.

On 2/14/2012 9:05 PM, wrote:
....

Except if you look at the pictures it has no carb - so no float, and
no accelerator pump.

Yeah, the age got me thinking later and so I went and did look--it is,
as I now see others have also noted (including you ) the TBI system.

I have already posted to Iggy to forget about what had said and the
difference...

--

On 2012-02-15, Pete C. wrote:

Ignoramus10095 wrote:

On 2012-02-15, dpb wrote:
On 2/14/2012 7:14 PM, Ignoramus10095 wrote:
...

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however, have
those electric valves on top. It might have a bowl, but its location
is not obvious or visible.
...

I hadn't looked at the closeup pictures before, but just did after
thinking about the year. It's one of the hybrid injection systems.
I've had a couple but never had to work on one so forget the earlier
thoughts posted--they're not pertinent to these.

I think the phrase is "throttle body injection" for looking for information.

If I were to hazard a complete guess, it would be after two years idle
the injectors are plugged. How to attack them, specifically, I don't
know, sorry.

--

How do they work, do they create pressure, or are they just valves,
with the pressure created by the in-tank pump?

i

A fuel injector is just a solenoid actuated spray nozzle. The in-tank
pump provides the fuel pressure and the pressure regulator regulates
that pressure sending excess fuel back to the tank via the return line.

OK, now I have the picture, I think. I am now thinking of proper ways
to troubleshoot this.

I guess that a first test would be to activate the fuel pump without
cranking (by turning the ignirion key almost to the crank position),
and apply 12v to the injectors.

Depending on whether they spray fuel or not, I will know what is wrong
or at least will move in the right direction.

Thanks

i

"Ignoramus10095" wrote in message
...
On 2012-02-15, Pete C. wrote:

Ignoramus10095 wrote:

On 2012-02-15, dpb wrote:
On 2/14/2012 7:14 PM, Ignoramus10095 wrote:
...

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however, have
those electric valves on top. It might have a bowl, but its location
is not obvious or visible.
...

I hadn't looked at the closeup pictures before, but just did after
thinking about the year. It's one of the hybrid injection systems.
I've had a couple but never had to work on one so forget the earlier
thoughts posted--they're not pertinent to these.

I think the phrase is "throttle body injection" for looking for
information.

If I were to hazard a complete guess, it would be after two years idle
the injectors are plugged. How to attack them, specifically, I don't
know, sorry.

--

How do they work, do they create pressure, or are they just valves,
with the pressure created by the in-tank pump?

i

A fuel injector is just a solenoid actuated spray nozzle. The in-tank
pump provides the fuel pressure and the pressure regulator regulates
that pressure sending excess fuel back to the tank via the return line.

OK, now I have the picture, I think. I am now thinking of proper ways
to troubleshoot this.

I guess that a first test would be to activate the fuel pump without
cranking (by turning the ignirion key almost to the crank position),
and apply 12v to the injectors.

Depending on whether they spray fuel or not, I will know what is wrong
or at least will move in the right direction.

Thanks

i


To be kind to the injector coils I'd only apply full 12V to the injectors
for a second or so. Normally injector drive circuits limit the current or
PWM after the injector opens.

"Dennis" wrote in message
...

"Ignoramus10095" wrote in message
...
On 2012-02-15, Pete C. wrote:

Ignoramus10095 wrote:

On 2012-02-15, dpb wrote:
On 2/14/2012 7:14 PM, Ignoramus10095 wrote:
...

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however,
have
those electric valves on top. It might have a bowl, but its location
is not obvious or visible.
...

I hadn't looked at the closeup pictures before, but just did after
thinking about the year. It's one of the hybrid injection systems.
I've had a couple but never had to work on one so forget the earlier
thoughts posted--they're not pertinent to these.

I think the phrase is "throttle body injection" for looking for
information.

If I were to hazard a complete guess, it would be after two years
idle
the injectors are plugged. How to attack them, specifically, I don't
know, sorry.

--

How do they work, do they create pressure, or are they just valves,
with the pressure created by the in-tank pump?

i

A fuel injector is just a solenoid actuated spray nozzle. The in-tank
pump provides the fuel pressure and the pressure regulator regulates
that pressure sending excess fuel back to the tank via the return line.

OK, now I have the picture, I think. I am now thinking of proper ways
to troubleshoot this.

I guess that a first test would be to activate the fuel pump without
cranking (by turning the ignirion key almost to the crank position),
and apply 12v to the injectors.

Depending on whether they spray fuel or not, I will know what is wrong
or at least will move in the right direction.

Thanks

i


To be kind to the injector coils I'd only apply full 12V to the injectors
for a second or so. Normally injector drive circuits limit the current or
PWM after the injector opens.

I probably would just check for the presence of voltage at the injector coil
during cranking.

Eliminates pretty much everything but clogged injector.

On 2012-02-15, PrecisionmachinisT wrote:

"Dennis" wrote in message
...

"Ignoramus10095" wrote in message
...
On 2012-02-15, Pete C. wrote:

Ignoramus10095 wrote:

On 2012-02-15, dpb wrote:
On 2/14/2012 7:14 PM, Ignoramus10095 wrote:
...

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however,
have
those electric valves on top. It might have a bowl, but its location
is not obvious or visible.
...

I hadn't looked at the closeup pictures before, but just did after
thinking about the year. It's one of the hybrid injection systems.
I've had a couple but never had to work on one so forget the earlier
thoughts posted--they're not pertinent to these.

I think the phrase is "throttle body injection" for looking for
information.

If I were to hazard a complete guess, it would be after two years
idle
the injectors are plugged. How to attack them, specifically, I don't
know, sorry.

--

How do they work, do they create pressure, or are they just valves,
with the pressure created by the in-tank pump?

i

A fuel injector is just a solenoid actuated spray nozzle. The in-tank
pump provides the fuel pressure and the pressure regulator regulates
that pressure sending excess fuel back to the tank via the return line.

OK, now I have the picture, I think. I am now thinking of proper ways
to troubleshoot this.

I guess that a first test would be to activate the fuel pump without
cranking (by turning the ignirion key almost to the crank position),
and apply 12v to the injectors.

Depending on whether they spray fuel or not, I will know what is wrong
or at least will move in the right direction.

Thanks

i


To be kind to the injector coils I'd only apply full 12V to the injectors
for a second or so. Normally injector drive circuits limit the current or
PWM after the injector opens.

I probably would just check for the presence of voltage at the injector coil
during cranking.

Eliminates pretty much everything but clogged injector.



OK, now the 64,000 dollar question: can they be un-clogged?

i

"PrecisionmachinisT" wrote in message
news:RYKdnYQDn8Mz2KbSnZ2dnUVZ_hWdnZ2d@scnresearch. com...

"Dennis" wrote in message
...

"Ignoramus10095" wrote in message
...
On 2012-02-15, Pete C. wrote:

Ignoramus10095 wrote:

On 2012-02-15, dpb wrote:
On 2/14/2012 7:14 PM, Ignoramus10095 wrote:
...

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however,
have
those electric valves on top. It might have a bowl, but its
location
is not obvious or visible.
...

I hadn't looked at the closeup pictures before, but just did after
thinking about the year. It's one of the hybrid injection systems.
I've had a couple but never had to work on one so forget the earlier
thoughts posted--they're not pertinent to these.

I think the phrase is "throttle body injection" for looking for
information.

If I were to hazard a complete guess, it would be after two years
idle
the injectors are plugged. How to attack them, specifically, I
don't
know, sorry.

--

How do they work, do they create pressure, or are they just valves,
with the pressure created by the in-tank pump?

i

A fuel injector is just a solenoid actuated spray nozzle. The in-tank
pump provides the fuel pressure and the pressure regulator regulates
that pressure sending excess fuel back to the tank via the return line.

OK, now I have the picture, I think. I am now thinking of proper ways
to troubleshoot this.

I guess that a first test would be to activate the fuel pump without
cranking (by turning the ignirion key almost to the crank position),
and apply 12v to the injectors.

Depending on whether they spray fuel or not, I will know what is wrong
or at least will move in the right direction.

Thanks

i


To be kind to the injector coils I'd only apply full 12V to the injectors
for a second or so. Normally injector drive circuits limit the current
or PWM after the injector opens.

I probably would just check for the presence of voltage at the injector
coil during cranking.

Eliminates pretty much everything but clogged injector.


IIRC at least some are low side driven. They have +12 supplied all the time
and the injector is opened by taking the other coil pin to ground. But
you're right, no +12 will mean no fuel.

"Ignoramus10095" wrote in message
...
On 2012-02-15, PrecisionmachinisT
wrote:

"Dennis" wrote in message
...

"Ignoramus10095" wrote in message
...
On 2012-02-15, Pete C. wrote:

Ignoramus10095 wrote:

On 2012-02-15, dpb wrote:
On 2/14/2012 7:14 PM, Ignoramus10095 wrote:
...

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however,
have
those electric valves on top. It might have a bowl, but its
location
is not obvious or visible.
...

I hadn't looked at the closeup pictures before, but just did after
thinking about the year. It's one of the hybrid injection systems.
I've had a couple but never had to work on one so forget the
earlier
thoughts posted--they're not pertinent to these.

I think the phrase is "throttle body injection" for looking for
information.

If I were to hazard a complete guess, it would be after two years
idle
the injectors are plugged. How to attack them, specifically, I
don't
know, sorry.

--

How do they work, do they create pressure, or are they just valves,
with the pressure created by the in-tank pump?

i

A fuel injector is just a solenoid actuated spray nozzle. The in-tank
pump provides the fuel pressure and the pressure regulator regulates
that pressure sending excess fuel back to the tank via the return
line.

OK, now I have the picture, I think. I am now thinking of proper ways
to troubleshoot this.

I guess that a first test would be to activate the fuel pump without
cranking (by turning the ignirion key almost to the crank position),
and apply 12v to the injectors.

Depending on whether they spray fuel or not, I will know what is wrong
or at least will move in the right direction.

Thanks

i


To be kind to the injector coils I'd only apply full 12V to the
injectors
for a second or so. Normally injector drive circuits limit the current
or
PWM after the injector opens.

I probably would just check for the presence of voltage at the injector
coil
during cranking.

Eliminates pretty much everything but clogged injector.



OK, now the 64,000 dollar question: can they be un-clogged?


I would think soaking them in fresh gasoline should probably
do the trick

"Dennis" wrote in message
. au...

"PrecisionmachinisT" wrote in message
news:RYKdnYQDn8Mz2KbSnZ2dnUVZ_hWdnZ2d@scnresearch. com...

"Dennis" wrote in message
...

"Ignoramus10095" wrote in message
...
On 2012-02-15, Pete C. wrote:

Ignoramus10095 wrote:

On 2012-02-15, dpb wrote:
On 2/14/2012 7:14 PM, Ignoramus10095 wrote:
...

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however,
have
those electric valves on top. It might have a bowl, but its
location
is not obvious or visible.
...

I hadn't looked at the closeup pictures before, but just did after
thinking about the year. It's one of the hybrid injection systems.
I've had a couple but never had to work on one so forget the
earlier
thoughts posted--they're not pertinent to these.

I think the phrase is "throttle body injection" for looking for
information.

If I were to hazard a complete guess, it would be after two years
idle
the injectors are plugged. How to attack them, specifically, I
don't
know, sorry.

--

How do they work, do they create pressure, or are they just valves,
with the pressure created by the in-tank pump?

i

A fuel injector is just a solenoid actuated spray nozzle. The in-tank
pump provides the fuel pressure and the pressure regulator regulates
that pressure sending excess fuel back to the tank via the return
line.

OK, now I have the picture, I think. I am now thinking of proper ways
to troubleshoot this.

I guess that a first test would be to activate the fuel pump without
cranking (by turning the ignirion key almost to the crank position),
and apply 12v to the injectors.

Depending on whether they spray fuel or not, I will know what is wrong
or at least will move in the right direction.

Thanks

i


To be kind to the injector coils I'd only apply full 12V to the
injectors for a second or so. Normally injector drive circuits limit
the current or PWM after the injector opens.

I probably would just check for the presence of voltage at the injector
coil during cranking.

Eliminates pretty much everything but clogged injector.


IIRC at least some are low side driven. They have +12 supplied all the
time and the injector is opened by taking the other coil pin to ground.
But you're right, no +12 will mean no fuel.

Thinking you should still see *something* if you were to place the voltmeter
in parallel with the coil...might not be anywhere near to a full 12 volts
because of the pwm duty cycle but...

On 2012-02-15, Pete C. wrote:

Ignoramus10095 wrote:

On 2012-02-15, Pete C. wrote:

azotic wrote:

"Ignoramus10095" wrote in message
...
On 2012-02-14, Winston wrote:
Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

(...)

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

Yup. But first, remove the contaminated gasoline
from the tank, pump and lines. Safest would be
to remove the gas tank and have it de-rusted,
cleaned and lined.

--Winston

We did this, thanks.

i

Onboard computer bad ?
Check fuel line pressure ?

Looks like throttle body injection (TBI), lots of stuff to go wrong.

Best Regards
Tom.

Yes, if it is TBI it does not have a carburetor, it has a throttle body
which only superficially looks like a carb. The TBI setup has an in-tank
high(er) pressure fuel pump and two fuel injectors in the throttle body.
You can check to see if the injectors are being opened by the PCM with
"NOID" lights which you can usually borrow from an auto parts place
(with deposit). If the injectors are getting driven by the PCM they may
well be clogged/stuck, I don't believe a set of those injectors is all
that expensive. If they are not getting driven by the PCM there could be
issues with sensors like crankshaft or camshaft position.

What model year is it? I had a 1990 FS Blazer with the TBI 350 and the
TBI 454 was an option. I *think* I still have the manuals for it around.

This does seem to be TBI (not that I know much) and the engine is a
Chevy 454!

If you have anything on it, I would love to get a copy or a scan!

Thanks a lot!

i

http://wpnet.us/TBI_Fuel_Control.pdf

Sorry it's not in order, my scanner has ADF but no provisions for double
sided.

Pete, thanks, I have downloaded it and I am studying it.

i

On 2012-02-15, wrote:
On Tue, 14 Feb 2012 17:10:19 -0600, Ignoramus10095
wrote:

I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

Supposedly, and I believe the person who told me the story because I
know him very well, a pump gasoline inside the gas tank went bad on
it. A while ago, tank was disconnected and we put it back when we got
the truck.

Truck sat outside for 2 years without any further work.

We bought a new pump from NAPA.

The truck cranks, but would not start without fuel added to carb.

If I remove the nut holding the line near the carb, then gas pours out
of it when the pump in the gas tank is activated. So, gas gets to the
carburetor.

If I pour gasoline in the carburetor, the engine starts great. It
also runs great when the engine runs and I continuously add a small
stream of gas to the carb.

However, without that stream, it does not get any gas.

There are two electric valves in the carb. If my guy cranks the motor
and presses the gas pedal, I see some drops of gasoline, but not
nearly enough for this Chevy 454 engine.

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i
. Except it is not a carb. You have a TBI engine - throttle body
injected. What year is the puppy? If it is pre-1996 a good code
scanner can tell you everything you need to know, if you know what you
need to know - if you know what I mean.

The two "solenoids" are fuel injectors - and the other part - the
metal hat with the adjuster screw in it is the fuel pressure
regulator. See if the connection to one injector has 12 volts on one
side any time the key is on and it a 12 volt lamp (test light, noid
light, or 194 side marker lamp in socket) connected across the
connector flashes when the engine is turned over. If you have 12 volts
and the light flashes the injectors or regulator are likely the
problem. If not, you have electrical problems. Ther will be a "shrader
valve" somewhere on the fuel line. You need to verify your fuel
pressure. It should be roughly 10-12 PSI if my memory serves
correctly.

If it is pre 1996 you can get the trouble codes off the check engine
light by shorting terminal A to B on the aldl connector. That's the
two end terminals of the top row on the right side.

You should get a code 12 - flash - - flash flash.

Look for a code 33 or 34 (map sensor), 54 (fuel pump circuit) 55 (bad
ECM) 21 or 22 (throttle position switch), or 14 or 15 (intake air temp
sensor) Any other codes should not prevent it from starting. Also be
sure you ARE getting spark. No spark usually means no trigger for the
injectors as well.

A somple injector function test is a stethoscope - you should hear
them go "tick-tick" when the engine is cranked.

Do you think that I should try to clean them in an ultrasonic cleaner?

If so, what liquid should I use for cleaning?

Also, if I need to clean them with ultrasound, should I submerge them
completely?

i

Ignoramus10095 wrote:

On 2012-02-15, PrecisionmachinisT wrote:

"Dennis" wrote in message
...

"Ignoramus10095" wrote in message
...
On 2012-02-15, Pete C. wrote:

Ignoramus10095 wrote:

On 2012-02-15, dpb wrote:
On 2/14/2012 7:14 PM, Ignoramus10095 wrote:
...

dpb, here's where I am lost.

The carburetor, visibly, does NOT have a bowl. It does, however,
have
those electric valves on top. It might have a bowl, but its location
is not obvious or visible.
...

I hadn't looked at the closeup pictures before, but just did after
thinking about the year. It's one of the hybrid injection systems.
I've had a couple but never had to work on one so forget the earlier
thoughts posted--they're not pertinent to these.

I think the phrase is "throttle body injection" for looking for
information.

If I were to hazard a complete guess, it would be after two years
idle
the injectors are plugged. How to attack them, specifically, I don't
know, sorry.

--

How do they work, do they create pressure, or are they just valves,
with the pressure created by the in-tank pump?

i

A fuel injector is just a solenoid actuated spray nozzle. The in-tank
pump provides the fuel pressure and the pressure regulator regulates
that pressure sending excess fuel back to the tank via the return line.

OK, now I have the picture, I think. I am now thinking of proper ways
to troubleshoot this.

I guess that a first test would be to activate the fuel pump without
cranking (by turning the ignirion key almost to the crank position),
and apply 12v to the injectors.

Depending on whether they spray fuel or not, I will know what is wrong
or at least will move in the right direction.

Thanks

i


To be kind to the injector coils I'd only apply full 12V to the injectors
for a second or so. Normally injector drive circuits limit the current or
PWM after the injector opens.

I probably would just check for the presence of voltage at the injector coil
during cranking.

Eliminates pretty much everything but clogged injector.



OK, now the 64,000 dollar question: can they be un-clogged?

i

If they are clogged they are pretty cheap. A quick search on Autozone
has 1990 Chev TBI 7.4 injectors at $65ea.

Ignoramus10095 wrote:

On 2012-02-15, wrote:
On Tue, 14 Feb 2012 17:10:19 -0600, Ignoramus10095
wrote:

I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

Supposedly, and I believe the person who told me the story because I
know him very well, a pump gasoline inside the gas tank went bad on
it. A while ago, tank was disconnected and we put it back when we got
the truck.

Truck sat outside for 2 years without any further work.

We bought a new pump from NAPA.

The truck cranks, but would not start without fuel added to carb.

If I remove the nut holding the line near the carb, then gas pours out
of it when the pump in the gas tank is activated. So, gas gets to the
carburetor.

If I pour gasoline in the carburetor, the engine starts great. It
also runs great when the engine runs and I continuously add a small
stream of gas to the carb.

However, without that stream, it does not get any gas.

There are two electric valves in the carb. If my guy cranks the motor
and presses the gas pedal, I see some drops of gasoline, but not
nearly enough for this Chevy 454 engine.

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i
. Except it is not a carb. You have a TBI engine - throttle body
injected. What year is the puppy? If it is pre-1996 a good code
scanner can tell you everything you need to know, if you know what you
need to know - if you know what I mean.

The two "solenoids" are fuel injectors - and the other part - the
metal hat with the adjuster screw in it is the fuel pressure
regulator. See if the connection to one injector has 12 volts on one
side any time the key is on and it a 12 volt lamp (test light, noid
light, or 194 side marker lamp in socket) connected across the
connector flashes when the engine is turned over. If you have 12 volts
and the light flashes the injectors or regulator are likely the
problem. If not, you have electrical problems. Ther will be a "shrader
valve" somewhere on the fuel line. You need to verify your fuel
pressure. It should be roughly 10-12 PSI if my memory serves
correctly.

If it is pre 1996 you can get the trouble codes off the check engine
light by shorting terminal A to B on the aldl connector. That's the
two end terminals of the top row on the right side.

You should get a code 12 - flash - - flash flash.

Look for a code 33 or 34 (map sensor), 54 (fuel pump circuit) 55 (bad
ECM) 21 or 22 (throttle position switch), or 14 or 15 (intake air temp
sensor) Any other codes should not prevent it from starting. Also be
sure you ARE getting spark. No spark usually means no trigger for the
injectors as well.

A somple injector function test is a stethoscope - you should hear
them go "tick-tick" when the engine is cranked.

Do you think that I should try to clean them in an ultrasonic cleaner?

If so, what liquid should I use for cleaning?

Also, if I need to clean them with ultrasound, should I submerge them
completely?

i

Page 4-23 of the docs I scanned say that the fuel injectors should not
be submerged in any type of liquid solvent or cleaner.

Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

Supposedly, and I believe the person who told me the story because I
know him very well, a pump gasoline inside the gas tank went bad on
it. A while ago, tank was disconnected and we put it back when we got
the truck.

Truck sat outside for 2 years without any further work.

We bought a new pump from NAPA.

The truck cranks, but would not start without fuel added to carb.

If I remove the nut holding the line near the carb, then gas pours out
of it when the pump in the gas tank is activated. So, gas gets to the
carburetor.

If I pour gasoline in the carburetor, the engine starts great. It
also runs great when the engine runs and I continuously add a small
stream of gas to the carb.

However, without that stream, it does not get any gas.

There are two electric valves in the carb. If my guy cranks the motor
and presses the gas pedal, I see some drops of gasoline, but not
nearly enough for this Chevy 454 engine.

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

2 years on a dry carb means you will need a kit and clean and rebuild
the carb.

--
Steve W.

Ignoramus10095 wrote:
I have a Chevy Kodiak dump truck that I am trying to fix.

Pictures of the truck and carburetor are he

http://igor.chudov.com/tmp/Chevy-Kodiak/

Supposedly, and I believe the person who told me the story because I
know him very well, a pump gasoline inside the gas tank went bad on
it. A while ago, tank was disconnected and we put it back when we got
the truck.

Truck sat outside for 2 years without any further work.

We bought a new pump from NAPA.

The truck cranks, but would not start without fuel added to carb.

If I remove the nut holding the line near the carb, then gas pours out
of it when the pump in the gas tank is activated. So, gas gets to the
carburetor.

If I pour gasoline in the carburetor, the engine starts great. It
also runs great when the engine runs and I continuously add a small
stream of gas to the carb.

However, without that stream, it does not get any gas.

There are two electric valves in the carb. If my guy cranks the motor
and presses the gas pedal, I see some drops of gasoline, but not
nearly enough for this Chevy 454 engine.

Any ideas what could be wrong? Carb cleanout and rebuild necessary?

thanks

i

Should have looked at the pictures. That is NOT a carb. It is fuel
injected. If you installed a pump for a carbed truck you have the wrong
pump. If you installed the injected pump then you need to flush the
injectors with cleaner.

--
Steve W.