Had a curious event happen today. The family went out to Sweet Tomatoes
(salad bar buffet restaurant chain)
today, my 20 year-old daughter drove the 2000 Toyota Siena van. While
getting on the highway, she floored
it for about 10-15 seconds to be able to merge in front of a monster RV
(greyhoud-bus class). She commented
about the car "shaking" right after that. I didn't notice it at first,
but soon it was more pronounced, felt like
an intermittent miss. Later, it got worse, I stopped by an auto parts
store on the way back home and bought
a set of spark plugs, taking a wild stab at what it might be, and
knowing they hadn't been changed in forever.

The rear plugs are a total bear on this car, but the internet helped me
find out you take the cowl panel with the
windshield wiper mechanism out to get access to the rear bank of the
engine. One plug of the rear bank
had the ground electrode bent all the way against the center electrode.
I don't THINK I manhandled it enough
to do that getting the plug out of the well and past the intake
manifold, but I can't be absolutely sure of that.
Obviously, the plug wasn't like that before the misbehavior, could a
severe knock do that to a plug? Could a chunk
of carbon have come off the piston and crunched the plug electrode? It
was bent, but not totally smashed.

This car has no distributor, and has 3 spark coils. So, each coil
serves two cylinders. What happens if one plug
is shorted? Does that short out the other plug, too? Was the other
cylinder missing intermittently, as the coil
barely had enough current to make a weak spark with one plug shorted?
The shorted plug was on the branch
with the long plug wire, the coils are on top of the front bank plugs.

Got all the plugs back in, started it up and it ran smoothly. I didn't
drive it yet, but before the work it was
running so badly I thought it might leave us stranded. Unless it needs
the leaner mixture for a warmed-up engine
to misbehave, it sure feels like it is fixed. The check engine light
came on as we were driving home,
I was waiting for that to happen.

Anyway, has anyone had an experience like this, where there was very
obvious ignition miss immediately after a
full throttle acceleration? I've had plenty of dirty spark plugs and
bad plug wires over the years, and they generally
slowly got worse. I've never had a miss develop suddenly while
driving. All the old plugs looked quite normal,
although the gaps were all worn a bit.

Jon

On Mon, 30 Aug 2010 00:34:04 -0500, Jon Elson wrote:



The rear plugs are a total bear on this car, but the internet helped me
find out you take the cowl panel with the
windshield wiper mechanism out to get access to the rear bank of the
engine. One plug of the rear bank
had the ground electrode bent all the way against the center electrode.
I don't THINK I manhandled it enough
to do that getting the plug out of the well and past the intake
manifold, but I can't be absolutely sure of that.
Obviously, the plug wasn't like that before the misbehavior, could a
severe knock do that to a plug? Could a chunk
of carbon have come off the piston and crunched the plug electrode? It
was bent, but not totally smashed.

This car has no distributor, and has 3 spark coils. So, each coil
serves two cylinders. What happens if one plug
is shorted? Does that short out the other plug, too? Was the other
cylinder missing intermittently, as the coil
barely had enough current to make a weak spark with one plug shorted?
The shorted plug was on the branch
with the long plug wire, the coils are on top of the front bank plugs.



If that plug was wet with fuel or fouled when you took it out then it could
have been pre-existing. If the insulator looked similar to the other plugs,
then it happened as you took it out.

The most likely cause for getting a miss starting on one cylinder after a bit
of hard acceleration, that then comes and goes, is that the insulation has
broken down on one of the three coils. If you can access the coils and inspect
them _very_ closely, you may see a small burned spot. Or you may not :-(

It'll probably only affect one cylinder, even though they are shared coils,
this is because the coils are double ended, not parallel connections.

A coil swap is usually quicker than a plug swap on these modern engines :-|


HTH

Mark Rand
RTFM

On Aug 30, 1:34*am, Jon Elson wrote:
Had a curious event happen today. *The family went out to Sweet Tomatoes
(salad bar buffet restaurant chain)
today, my 20 year-old daughter drove the 2000 Toyota Siena van. *While
getting on the highway, she floored
it for about 10-15 seconds to be able to merge in front of a monster RV
(greyhoud-bus class). *She commented
about the car "shaking" right after that. *I didn't notice it at first,
but soon it was more pronounced, felt like
an intermittent miss. *Later, it got worse, I stopped by an auto parts
store on the way back home and bought
a set of spark plugs, taking a wild stab at what it might be, and
knowing they hadn't been changed in forever.

The rear plugs are a total bear on this car, but the internet helped me
find out you take the cowl panel with the
windshield wiper mechanism out to get access to the rear bank of the
engine. *One plug of the rear bank
had the ground electrode bent all the way against the center electrode. *
I don't THINK I manhandled it enough
to do that getting the plug out of the well and past the intake
manifold, but I can't be absolutely sure of that.
Obviously, the plug wasn't like that before the misbehavior, could a
severe knock do that to a plug? *Could a chunk
of carbon have come off the piston and crunched the plug electrode? *It
was bent, but not totally smashed.

This car has no distributor, and has 3 spark coils. *So, each coil
serves two cylinders. *What happens if one plug
is shorted? *Does that short out the other plug, too? *Was the other
cylinder missing intermittently, as the coil
barely had enough current to make a weak spark with one plug shorted? *
The shorted plug was on the branch
with the long plug wire, the coils are on top of the front bank plugs.

Got all the plugs back in, started it up and it ran smoothly. *I didn't
drive it yet, but before the work it was
running so badly I thought it might leave us stranded. *Unless it needs
the leaner mixture for a warmed-up engine
to misbehave, it sure feels like it is fixed. *The check engine light
came on as we were driving home,
I was waiting for that to happen.

Anyway, has anyone had an experience like this, where there was very
obvious ignition miss immediately after a
full throttle acceleration? *I've had plenty of dirty spark plugs and
bad plug wires over the years, and they generally
slowly got worse. *I've never had a miss develop suddenly while
driving. *All the old plugs looked quite normal,
although the gaps were all worn a bit.

Jon

I'd have to go with a chunk of *something* in the cylinder. Carbon is
always a possibility, probably from the EGR system.

Could have been a piece of anything from the intake tracts, from build
day or a service, waiting to get jostled just right.

Make sure it has an air filter in it.


Dave

Jon Elson wrote:
Had a curious event happen today. The family went out to Sweet Tomatoes
(salad bar buffet restaurant chain)
today, my 20 year-old daughter drove the 2000 Toyota Siena van. While
getting on the highway, she floored
it for about 10-15 seconds to be able to merge in front of a monster RV
(greyhoud-bus class). She commented
about the car "shaking" right after that. I didn't notice it at first,
but soon it was more pronounced, felt like
an intermittent miss. Later, it got worse, I stopped by an auto parts
store on the way back home and bought
a set of spark plugs, taking a wild stab at what it might be, and
knowing they hadn't been changed in forever.

The rear plugs are a total bear on this car, but the internet helped me
find out you take the cowl panel with the
windshield wiper mechanism out to get access to the rear bank of the
engine. One plug of the rear bank
had the ground electrode bent all the way against the center electrode.
I don't THINK I manhandled it enough
to do that getting the plug out of the well and past the intake
manifold, but I can't be absolutely sure of that.
Obviously, the plug wasn't like that before the misbehavior, could a
severe knock do that to a plug? Could a chunk
of carbon have come off the piston and crunched the plug electrode? It
was bent, but not totally smashed.

Being a 2000 you probably had a chunk of carbon break free.
I would try running a can of seafoam through it using the instructions
on the can for "upper intake cleaning". Basically your going to run the
engine up to temp. Then use a vacuum line to draw in the seafoam until
the engine quits. Shut the key off and let it set for an hour or so.
Then start it back up and drive it a bit to blow all the loose crap out.

Word of MAJOR WARNING, DO NOT DO THIS PROCEDURE IN A GARAGE OR WITH THE
EXHAUST POINTING AT ANYTHING YOU WANT TO KEEP CLEAN!!!

It WILL generate a smoke cloud that will make you think the place is on
fire, and the loose carbon,crud and crap that come blasting out of the
exhaust is VERY sticky!!!



This car has no distributor, and has 3 spark coils. So, each coil
serves two cylinders. What happens if one plug
is shorted? Does that short out the other plug, too? Was the other
cylinder missing intermittently, as the coil
barely had enough current to make a weak spark with one plug shorted?
The shorted plug was on the branch
with the long plug wire, the coils are on top of the front bank plugs.

Got all the plugs back in, started it up and it ran smoothly. I didn't
drive it yet, but before the work it was
running so badly I thought it might leave us stranded. Unless it needs
the leaner mixture for a warmed-up engine
to misbehave, it sure feels like it is fixed. The check engine light
came on as we were driving home,
I was waiting for that to happen.

Anyway, has anyone had an experience like this, where there was very
obvious ignition miss immediately after a
full throttle acceleration? I've had plenty of dirty spark plugs and
bad plug wires over the years, and they generally
slowly got worse. I've never had a miss develop suddenly while
driving. All the old plugs looked quite normal,
although the gaps were all worn a bit.

Jon

With that plug grounded out it would have stopped both cylinders on that
coil from firing. Makes the engine S H A K E like a paint mixer...


--
Steve W.
(\___/)
(='.'=)
(")_(")

On Mon, 30 Aug 2010 10:55:57 -0400, "Steve W."
wrote:

Jon Elson wrote:
Had a curious event happen today. The family went out to Sweet Tomatoes
(salad bar buffet restaurant chain)
today, my 20 year-old daughter drove the 2000 Toyota Siena van. While
getting on the highway, she floored
it for about 10-15 seconds to be able to merge in front of a monster RV
(greyhoud-bus class). She commented
about the car "shaking" right after that. I didn't notice it at first,
but soon it was more pronounced, felt like
an intermittent miss. Later, it got worse, I stopped by an auto parts
store on the way back home and bought
a set of spark plugs, taking a wild stab at what it might be, and
knowing they hadn't been changed in forever.

The rear plugs are a total bear on this car, but the internet helped me
find out you take the cowl panel with the
windshield wiper mechanism out to get access to the rear bank of the
engine. One plug of the rear bank
had the ground electrode bent all the way against the center electrode.
I don't THINK I manhandled it enough
to do that getting the plug out of the well and past the intake
manifold, but I can't be absolutely sure of that.
Obviously, the plug wasn't like that before the misbehavior, could a
severe knock do that to a plug? Could a chunk
of carbon have come off the piston and crunched the plug electrode? It
was bent, but not totally smashed.

Being a 2000 you probably had a chunk of carbon break free.
I would try running a can of seafoam through it using the instructions
on the can for "upper intake cleaning". Basically your going to run the
engine up to temp. Then use a vacuum line to draw in the seafoam until
the engine quits. Shut the key off and let it set for an hour or so.
Then start it back up and drive it a bit to blow all the loose crap out.

Word of MAJOR WARNING, DO NOT DO THIS PROCEDURE IN A GARAGE OR WITH THE
EXHAUST POINTING AT ANYTHING YOU WANT TO KEEP CLEAN!!!

It WILL generate a smoke cloud that will make you think the place is on
fire, and the loose carbon,crud and crap that come blasting out of the
exhaust is VERY sticky!!!



This car has no distributor, and has 3 spark coils. So, each coil
serves two cylinders. What happens if one plug
is shorted? Does that short out the other plug, too? Was the other
cylinder missing intermittently, as the coil
barely had enough current to make a weak spark with one plug shorted?
The shorted plug was on the branch
with the long plug wire, the coils are on top of the front bank plugs.

Got all the plugs back in, started it up and it ran smoothly. I didn't
drive it yet, but before the work it was
running so badly I thought it might leave us stranded. Unless it needs
the leaner mixture for a warmed-up engine
to misbehave, it sure feels like it is fixed. The check engine light
came on as we were driving home,
I was waiting for that to happen.

Anyway, has anyone had an experience like this, where there was very
obvious ignition miss immediately after a
full throttle acceleration? I've had plenty of dirty spark plugs and
bad plug wires over the years, and they generally
slowly got worse. I've never had a miss develop suddenly while
driving. All the old plugs looked quite normal,
although the gaps were all worn a bit.

Jon

With that plug grounded out it would have stopped both cylinders on that
coil from firing. Makes the engine S H A K E like a paint mixer...


No, a grounded plug on a double-ended coil affects ONLY the cyl with
the damage. BOTH plugs fire at the same time, every time. With the one
plug grounded, the other plug gets the full charge, just like with a
coil per plug system, or a conventional distributor type system, where
the "inner" end of the coil secondary is grounded.

On Mon, 30 Aug 2010 10:55:57 -0400, "Steve W."
wrote:

Word of MAJOR WARNING, DO NOT DO THIS PROCEDURE IN A GARAGE OR WITH THE
EXHAUST POINTING AT ANYTHING YOU WANT TO KEEP CLEAN!!!

It WILL generate a smoke cloud that will make you think the place is on
fire, and the loose carbon,crud and crap that come blasting out of the
exhaust is VERY sticky!!!


And we know this how?
G

Gunner


I am the Sword of my Family
and the Shield of my Nation.
If sent, I will crush everything you have built,
burn everything you love,
and kill every one of you.
(Hebrew quote)

Gunner Asch wrote:
On Mon, 30 Aug 2010 10:55:57 -0400, "Steve W."
wrote:

Word of MAJOR WARNING, DO NOT DO THIS PROCEDURE IN A GARAGE OR WITH THE
EXHAUST POINTING AT ANYTHING YOU WANT TO KEEP CLEAN!!!

It WILL generate a smoke cloud that will make you think the place is on
fire, and the loose carbon,crud and crap that come blasting out of the
exhaust is VERY sticky!!!


And we know this how?
G

Gunner


I am the Sword of my Family
and the Shield of my Nation.
If sent, I will crush everything you have built,
burn everything you love,
and kill every one of you.
(Hebrew quote)


SOP to warn folks. I've used it and GMs top cylinder cleaner quite a few
times. There is a fine print warning on the can and some folks don't
bother reading it. One friend of mine didn't pay attention to my warning
and had to repaint a section of his garage wall and air it out for about
2 days.

I know of a person on a list I'm on who was actually pulled over by the
police while he drove around to burn off the cleaner. They thought the
car was on fire!!

--
Steve W.
(\___/)
(='.'=)
(")_(")

On Mon, 30 Aug 2010 22:17:44 -0400, "Steve W."
wrote:

Gunner Asch wrote:
On Mon, 30 Aug 2010 10:55:57 -0400, "Steve W."
wrote:

Word of MAJOR WARNING, DO NOT DO THIS PROCEDURE IN A GARAGE OR WITH THE
EXHAUST POINTING AT ANYTHING YOU WANT TO KEEP CLEAN!!!

It WILL generate a smoke cloud that will make you think the place is on
fire, and the loose carbon,crud and crap that come blasting out of the
exhaust is VERY sticky!!!


And we know this how?
G

Gunner


I am the Sword of my Family
and the Shield of my Nation.
If sent, I will crush everything you have built,
burn everything you love,
and kill every one of you.
(Hebrew quote)


SOP to warn folks. I've used it and GMs top cylinder cleaner quite a few
times. There is a fine print warning on the can and some folks don't
bother reading it. One friend of mine didn't pay attention to my warning
and had to repaint a section of his garage wall and air it out for about
2 days.

I know of a person on a list I'm on who was actually pulled over by the
police while he drove around to burn off the cleaner. They thought the
car was on fire!!


Ok. I was just wondering if you had found this out personally.

Something Ive never done. Oh no..not me!

I did however do something similar in my last garage, when trying the
"Decarbon by pouring water down the carby while racing the engine"
trick.

Got the carbon out of that old truck. Sure as hell did! Worked great! I
think it cleaned out 30 yrs of carbon from that old 64 Chebby. Cleaned
out the muffler too!!! And the tailpipe..and the ashtray......

Only problem was..I too had to wash walls for 2 weeks to get rid of the
spooge....sigh..I ultimately had to buy a couple gallons of dish
soap..and marinate the walls for that **** to come loose.

It got so black in there..I had to run outside to breath. Seriously.


Gunner



I am the Sword of my Family
and the Shield of my Nation.
If sent, I will crush everything you have built,
burn everything you love,
and kill every one of you.
(Hebrew quote)

Jon Elson writes:

Anyway, has anyone had an experience like this, where there was very
obvious ignition miss immediately after a
full throttle acceleration?

Something like that happens if you occasioned damage to the torque
converter; it shudders from then on not unlike a missing cylinder. Of
course, replacing spark plugs won't help this.

Richard J Kinch wrote:
Jon Elson writes:

Anyway, has anyone had an experience like this, where there was very
obvious ignition miss immediately after a
full throttle acceleration?

Something like that happens if you occasioned damage to the torque
converter; it shudders from then on not unlike a missing cylinder. Of
course, replacing spark plugs won't help this.
Well, I didn't want to declare success until the car had been driven and
brought up to full engine temp, etc. I STILL don't know what the hell
happened, but it must have been in the plugs. I might Ohm them out
before chucking them. So, my wife drove it yesterday and said it ran
perfectly fine. The funny thing is it really felt like it was missing
on at least TWO cylinders, it was much more than a little rough at the
end, and continuing to get worse. We restarted it twice after the
initial rough running.

Jon

Jon Elson wrote:

This car has no distributor, and has 3 spark coils. So, each coil
serves two cylinders. What happens if one plug
is shorted? Does that short out the other plug, too?

Most coil pack systems fire two plugs at once. The secondary is connected plug tip,
block, block, and plug tip. Jumping the gap on the non compression plug is trivial. If
shorted, even easier.

Wes

Jon Elson wrote:

Anyway, has anyone had an experience like this, where there was very
obvious ignition miss immediately after a
full throttle acceleration? I've had plenty of dirty spark plugs and
bad plug wires over the years, and they generally
slowly got worse. I've never had a miss develop suddenly while
driving. All the old plugs looked quite normal,
although the gaps were all worn a bit.

The other thing you should do is ohm out your spark plug wires. 6-10 ohms. I've had a
bad wire make my 4 cylinder Saturn do the shakes. I put an old wire on it that I saved
and drove it for many miles.

Also look for arc over from boots on coil packs.

My car is about 52,000 miles since the last plug change and 70,000 since I changed the
wires according to Quicken. I hope to get this corrected this weekend. I have the parts
but it has been too freaking hot after work lately.

Responding made me do the research on my car. I bet my rough idle issues go away soon.

Wes

On Mon, 30 Aug 2010 22:19:12 -0500, Richard J Kinch
wrote:

Jon Elson writes:

Anyway, has anyone had an experience like this, where there was very
obvious ignition miss immediately after a
full throttle acceleration?

Something like that happens if you occasioned damage to the torque
converter; it shudders from then on not unlike a missing cylinder. Of
course, replacing spark plugs won't help this.
My PT cruiser has had an easy life for the last couple months, but
last weekend I floored it pretty good to pass a double trailer semi on
a two-lane - and it missed for the rest of the trip out (about another
10 miles) and all the way home (about 20 miles).
I was going to pull the plug wires to see which cyl was missing when I
got home - and low and behold, it idled PERFECTLY.
Hasn't missed a beat since, so I won't worry about it unless it starts
misbehaving again.

On Tue, 31 Aug 2010 18:50:27 -0400, Wes
wrote:

Jon Elson wrote:

Anyway, has anyone had an experience like this, where there was very
obvious ignition miss immediately after a
full throttle acceleration? I've had plenty of dirty spark plugs and
bad plug wires over the years, and they generally
slowly got worse. I've never had a miss develop suddenly while
driving. All the old plugs looked quite normal,
although the gaps were all worn a bit.

The other thing you should do is ohm out your spark plug wires. 6-10 ohms. I've had a
bad wire make my 4 cylinder Saturn do the shakes. I put an old wire on it that I saved
and drove it for many miles.

6 to 10 K ohms. Not 6-10 ohms with radio suppression wires.

Also look for arc over from boots on coil packs.

My car is about 52,000 miles since the last plug change and 70,000 since I changed the
wires according to Quicken. I hope to get this corrected this weekend. I have the parts
but it has been too freaking hot after work lately.

Responding made me do the research on my car. I bet my rough idle issues go away soon.

Wes

"Jon Elson" wrote in message
...
Richard J Kinch wrote:
Jon Elson writes:

Anyway, has anyone had an experience like this, where there was very
obvious ignition miss immediately after a
full throttle acceleration?

Something like that happens if you occasioned damage to the torque
converter; it shudders from then on not unlike a missing cylinder. Of
course, replacing spark plugs won't help this.
Well, I didn't want to declare success until the car had been driven and
brought up to full engine temp, etc. I STILL don't know what the hell
happened, but it must have been in the plugs. I might Ohm them out
before chucking them. So, my wife drove it yesterday and said it ran
perfectly fine. The funny thing is it really felt like it was missing
on at least TWO cylinders, it was much more than a little rough at the
end, and continuing to get worse. We restarted it twice after the
initial rough running.

Jon

My old 4 cyl Toyota PU had an intermittant rough running problem.
It always happened on the road and was fine as soon as I got home.
One night it happened again and I pulled off and popped the hood to
see what was happening. I heard a odd tick-tick-tick like an electrical
discharge but there was no visible sparking. Back at home it was
running ok as usual so I pulled the plugs - all ok. Ohmed out the plug
wires - all ok. I bought a new set of wires, they were cheap enough,
and installed them. Ever since it has been running perfectly and my gas
mileage has gone up 10% too.
Art

On Tue, 31 Aug 2010 20:42:30 -0400, wrote:

On Mon, 30 Aug 2010 22:19:12 -0500, Richard J Kinch
wrote:

Jon Elson writes:

Anyway, has anyone had an experience like this, where there was very
obvious ignition miss immediately after a
full throttle acceleration?

Something like that happens if you occasioned damage to the torque
converter; it shudders from then on not unlike a missing cylinder. Of
course, replacing spark plugs won't help this.
My PT cruiser has had an easy life for the last couple months, but
last weekend I floored it pretty good to pass a double trailer semi on
a two-lane - and it missed for the rest of the trip out (about another
10 miles) and all the way home (about 20 miles).
I was going to pull the plug wires to see which cyl was missing when I
got home - and low and behold, it idled PERFECTLY.
Hasn't missed a beat since, so I won't worry about it unless it starts
misbehaving again.
I have, on occasion, seen a bit of carbon caught between plug
electrodes.
Gerry :-)}
London, Canada

wrote:

On Mon, 30 Aug 2010 22:19:12 -0500, Richard J Kinch
? wrote:

?Jon Elson writes:
?
?? Anyway, has anyone had an experience like this, where there was very
?? obvious ignition miss immediately after a
?? full throttle acceleration?
?
?Something like that happens if you occasioned damage to the torque
?converter; it shudders from then on not unlike a missing cylinder. Of
?course, replacing spark plugs won't help this.
My PT cruiser has had an easy life for the last couple months, but
last weekend I floored it pretty good to pass a double trailer semi on
a two-lane - and it missed for the rest of the trip out (about another
10 miles) and all the way home (about 20 miles).
I was going to pull the plug wires to see which cyl was missing when I
got home - and low and behold, it idled PERFECTLY.
Hasn't missed a beat since, so I won't worry about it unless it starts
misbehaving again.


That sounds like the old stepvan I had. The gas tank was rusting,
and some flakes made it through the fuel pump and would cut off the flow
at the fuel filter if you pushed it. Shut it down, and they would drop
back to the fuel pump.


--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

wrote:

The other thing you should do is ohm out your spark plug wires. 6-10 ohms. I've had a
bad wire make my 4 cylinder Saturn do the shakes. I put an old wire on it that I saved
and drove it for many miles.

6 to 10 K ohms. Not 6-10 ohms with radio suppression wires.

Damn. You are correct. Spare keyboard, my normal one got drenched.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

Jon Elson wrote:
Well, I didn't want to declare success until the car had been driven
and brought up to full engine temp, etc. I STILL don't know what the
hell happened, but it must have been in the plugs. I might Ohm them
out before chucking them. So, my wife drove it yesterday and said it
ran perfectly fine. The funny thing is it really felt like it was
missing on at least TWO cylinders, it was much more than a little
rough at the end, and continuing to get worse. We restarted it twice
after the initial rough running.
OK, I Ohmed out the plugs, and one definitely had an open resistor. If
you really leaned on the center electrode
it would make intermittent contact, but otherwise was infinity Ohms.
The other plugs were difficult to measure
due to non-conductive deposits on the electrode, but if you poked
through that, most of them seemed to read
around 6 K Ohms. A couple others might also be a bit flaky, the
deposits made consistent readings difficult.

So, I did find an actual defect in at least one plug. I can imagine a
plug with a disintegrating resistor going
fully bad after a 10-15 second full-throttle sequence.

Jon