"Snuffy "Hub Cap" McKinney" wrote in message ...
What's a good way to test plug wires and coil without buying new parts? Parts stores around here only sell full sets of wires. I guess I could get one from a junk yard but would still want to test it.

OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting - after warming up runs smooth. Checking with ohmmeter, both wires are 7.1-7.2 ohms. For comparison, I checked the wire from another cylinder and it was 10 ohms.

=====

Gave up on the shade tree troubleshooting. Had it checked at a reliable mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not leaking. #1 plug, possibly other, was cracked. Replaced all plugs. Runs like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD gave bad info.

"Snuffy "Hub Cap" McKinney"
OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting -
after warming up runs smooth. Checking with ohmmeter, both wires are
7.1-7.2 ohms. For comparison, I checked the wire from another cylinder and
it was 10 ohms.

=====

Gave up on the shade tree troubleshooting. Had it checked at a reliable
mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not
leaking. #1 plug, possibly other, was cracked. Replaced all plugs. Runs
like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD gave
bad info.


OBD was correct.

Phil Kangas wrote:
"Snuffy "Hub Cap" McKinney"
OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting -
after warming up runs smooth. Checking with ohmmeter, both wires are
7.1-7.2 ohms. For comparison, I checked the wire from another cylinder and
it was 10 ohms.

=====

Gave up on the shade tree troubleshooting. Had it checked at a reliable
mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not
leaking. #1 plug, possibly other, was cracked. Replaced all plugs. Runs
like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD gave
bad info.


OBD was correct.

One trick to nail bad wire is to look at them under hood in the dark
when engine is running. Bad wire will cause mini fire work.

"Phil Kangas" wrote in message ...

"Snuffy "Hub Cap" McKinney"
OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting -
after warming up runs smooth. Checking with ohmmeter, both wires are
7.1-7.2 ohms. For comparison, I checked the wire from another cylinder and
it was 10 ohms.

=====

Gave up on the shade tree troubleshooting. Had it checked at a reliable
mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not
leaking. #1 plug, possibly other, was cracked. Replaced all plugs. Runs
like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD gave
bad info.


OBD was correct.

I can see it was right about the #1 and #4 misfires. Why was it correct about EGR having insuffient exhaust flow?

"Snuffy "Hub Cap" McKinney"
wrote in message
"Phil Kangas"
wrote in message

"Snuffy "Hub Cap" McKinney"
OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting -
after warming up runs smooth. Checking with ohmmeter, both wires are
7.1-7.2 ohms. For comparison, I checked the wire from another cylinder
and
it was 10 ohms.

=====

Gave up on the shade tree troubleshooting. Had it checked at a reliable
mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not
leaking. #1 plug, possibly other, was cracked. Replaced all plugs. Runs
like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD
gave
bad info.


OBD was correct.

I can see it was right about the #1 and #4 misfires. Why was it correct
about EGR having insuffient exhaust flow?


You did not say anything about EGR codes, only misfiring!

"Phil Kangas" wrote in message
...

"Snuffy "Hub Cap" McKinney"
wrote in message
"Phil Kangas"
wrote in message

"Snuffy "Hub Cap" McKinney"
OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting -
after warming up runs smooth. Checking with ohmmeter, both wires are
7.1-7.2 ohms. For comparison, I checked the wire from another cylinder
and
it was 10 ohms.

=====

Gave up on the shade tree troubleshooting. Had it checked at a reliable
mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not
leaking. #1 plug, possibly other, was cracked. Replaced all plugs.
Runs
like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD
gave
bad info.


OBD was correct.

I can see it was right about the #1 and #4 misfires. Why was it correct
about EGR having insuffient exhaust flow?


You did not say anything about EGR codes, only misfiring!
Different thread :-)
--
SC Tom

In alt.home.repair, on Thu, 27 Aug 2015 16:59:15 -0700, "Snuffy \"Hub
Cap\" McKinney" wrote:

"Snuffy "Hub Cap" McKinney" wrote in message ...
What's a good way to test plug wires and coil without buying new parts? Parts stores around here only sell full sets of wires.

I save some of the previous set of wires, in case my girlfriend's
brother steals some of mine. But they're useful for testing too.

Even from one car to the next. I save the longest ones, plus a center
one.

I guess I could get one from a junk yard but would still want to test it.

OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting - after warming up runs smooth. Checking with ohmmeter, both wires are 7.1-7.2 ohms. For comparison, I checked the wire from another cylinder and it was 10 ohms.

longer or shorter wire. The resistance should match length.

=====

Gave up on the shade tree troubleshooting. Had it checked at a reliable mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not leaking.

I once had a leaking head gasket according to the compression test. Two
adjacent cylinders in a V-8 were low. Car ran fine for 3 or 4 more
years. I think there's a difference between air escaping to the next
cylinder at cranking speeds versus running speeds. Much harder at
running speeds.

Although maybe if it were two diferent cylinders leaking hot exhaust
stroke gas would have ignited input or compression stroke gas in the
other cylinder. Can that happen?

#1 plug, possibly other, was cracked. Replaced all plugs. Runs like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD gave bad info.

"Phil Kangas" wrote in message ...

"Snuffy "Hub Cap" McKinney"
wrote in message
"Phil Kangas"
wrote in message

"Snuffy "Hub Cap" McKinney"
OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting -
after warming up runs smooth. Checking with ohmmeter, both wires are
7.1-7.2 ohms. For comparison, I checked the wire from another cylinder
and
it was 10 ohms.

=====

Gave up on the shade tree troubleshooting. Had it checked at a reliable
mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not
leaking. #1 plug, possibly other, was cracked. Replaced all plugs. Runs
like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD
gave
bad info.


OBD was correct.

I can see it was right about the #1 and #4 misfires. Why was it correct
about EGR having insuffient exhaust flow?


You did not say anything about EGR codes, only misfiring!

Oh,yeah, that's right. Sorry about that!

"Snuffy "Hub Cap" McKinney" wrote in message ...
"Phil Kangas" wrote in message ...

"Snuffy "Hub Cap" McKinney"
wrote in message
"Phil Kangas"
wrote in message

"Snuffy "Hub Cap" McKinney"
OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting -
after warming up runs smooth. Checking with ohmmeter, both wires are
7.1-7.2 ohms. For comparison, I checked the wire from another cylinder
and
it was 10 ohms.

=====

Gave up on the shade tree troubleshooting. Had it checked at a reliable
mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not
leaking. #1 plug, possibly other, was cracked. Replaced all plugs. Runs
like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD
gave
bad info.


OBD was correct.

I can see it was right about the #1 and #4 misfires. Why was it correct
about EGR having insuffient exhaust flow?


You did not say anything about EGR codes, only misfiring!

- Oh,yeah, that's right. Sorry about that!

I noticed today there is still a miss at 40-50 mph. Low speed is smooth. Will check the codes again tomorrow....

"Snuffy "Hub Cap" McKinney"
"Snuffy "Hub Cap" McKinney"
wrote in message
"Phil Kangas"
wrote in message

"Snuffy "Hub Cap" McKinney"
OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting -
after warming up runs smooth. Checking with ohmmeter, both wires are
7.1-7.2 ohms. For comparison, I checked the wire from another cylinder
and
it was 10 ohms.

=====

Gave up on the shade tree troubleshooting. Had it checked at a
reliable
mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not
leaking. #1 plug, possibly other, was cracked. Replaced all plugs.
Runs
like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD
gave
bad info.


OBD was correct.

I can see it was right about the #1 and #4 misfires. Why was it correct
about EGR having insuffient exhaust flow?


You did not say anything about EGR codes, only misfiring!

- Oh,yeah, that's right. Sorry about that!

I noticed today there is still a miss at 40-50 mph. Low speed is smooth.
Will check the codes again tomorrow....


It 'could' be a bad coil.. This happened on my '03 Buick.

On Thu, 27 Aug 2015 19:07:42 -0600, Tony Hwang
wrote:

Phil Kangas wrote:
"Snuffy "Hub Cap" McKinney"
OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting -
after warming up runs smooth. Checking with ohmmeter, both wires are
7.1-7.2 ohms. For comparison, I checked the wire from another cylinder and
it was 10 ohms.

=====

Gave up on the shade tree troubleshooting. Had it checked at a reliable
mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not
leaking. #1 plug, possibly other, was cracked. Replaced all plugs. Runs
like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD gave
bad info.


OBD was correct.

One trick to nail bad wire is to look at them under hood in the dark
when engine is running. Bad wire will cause mini fire work.
It MAY give fireworks. If the insulator is leaking. If the conductor
is open and the insulation is good you will see NOTHING.

On Thu, 27 Aug 2015 18:20:20 -0700, "Snuffy \"Hub Cap\" McKinney"
wrote:

"Phil Kangas" wrote in message ...

"Snuffy "Hub Cap" McKinney"
OBD2 shows cylinders 1 & 4 are misfiring. That's only when starting -
after warming up runs smooth. Checking with ohmmeter, both wires are
7.1-7.2 ohms. For comparison, I checked the wire from another cylinder and
it was 10 ohms.

=====

Gave up on the shade tree troubleshooting. Had it checked at a reliable
mechanic. Compression was 1.2 - 1.3 on all plugs. Head gasket was not
leaking. #1 plug, possibly other, was cracked. Replaced all plugs. Runs
like a sewing machine. EGR was fine.

So much for T/S by internet and "brand name" shops. Don't know why OBD gave
bad info.


OBD was correct.

I can see it was right about the #1 and #4 misfires. Why was it correct about EGR having insuffient exhaust flow?
Likely. With 2 bad plugs the vacuum is low and incosistent, causing
low EGR flow. The cause was bad plugs, but the result was low flow.
Knowing how emission controls work, and why, allowa a REAL mechanic to
determine what the problem really is. a 1 and 4 miss will virtually
NEVER be a head gasket..When there are multiple codes, you need to
figure out what can cause what - bad mixtures and bad flows can be
caused by misfires - and can also cause misfires - but generally not
consistent localized misfires.

Fix the simple obvious stuff first and most often the "strange" stuff
goes away as well.