Q: Cylinder #2 Not Firing (1997 Ford Mustang, V6, 3.8L)

1997 Ford Mustang, V6, 3.8L
- Car has lost power and engine is running rougher.
- Autozone diagnosed that cylinder 2 wasn't firing.
- Removed #2 spark plug wire from ignition module, held close to
module and no spark.
- Swapped #2 & #6 wires and #2 wire was okay.
- Cleaned and regapped #2 spark plug - didn't fix problem.
- Tested #2 plug by swapping #2 & #6 wires at ignition module and saw
a spark from #2 engine cylinder to #6 ignition module.
- Measured primary & secondary resistance on ignition module and they
were within specificaiton.
- Question1: what are possible causes of no spark from ignition coil
for cylinder #2 and how can I troubleshoot? Could it be a sensor or
computer problem?
- Question2: can I check ignition wires by measuring resistance with
an ohm meter?
- Comments: spark plugs need to be replaced but I don't think this is
the issue.

Tony wrote:
> 1997 Ford Mustang, V6, 3.8L
> - Car has lost power and engine is running rougher.
> - Autozone diagnosed that cylinder 2 wasn't firing.
> - Removed #2 spark plug wire from ignition module, held close to
> module and no spark.
> - Swapped #2 & #6 wires and #2 wire was okay.
> - Cleaned and regapped #2 spark plug - didn't fix problem.
> - Tested #2 plug by swapping #2 & #6 wires at ignition module and saw
> a spark from #2 engine cylinder to #6 ignition module.
> - Measured primary & secondary resistance on ignition module and they
> were within specificaiton.
> - Question1: what are possible causes of no spark from ignition coil
> for cylinder #2 and how can I troubleshoot? Could it be a sensor or
> computer problem?
> - Question2: can I check ignition wires by measuring resistance with
> an ohm meter?
> - Comments: spark plugs need to be replaced but I don't think this is
> the issue.

The 3.8L V-6s had head gasket issues and what you are describing sounds
to me like a blown head gasket. Before going through all the
diagnostics, and spending money on unneeded parts, I recommend looking
at the oil dipstick for traces of coolant and/or testing the coolant for
the presence of hydrocarbons. This is a simple test that any garage
should be able to do by dipping a strip of paper into the radiator and
seeing if it turns a certain color. If it shows positive for
hydrocarbons then my guess is you have a blown head gasket. You might
also want to get a compression test done (you can do this yourself very
easily with a gauge). This should difinitively tell you if there is a
head gasket problem.

Hello Michael,

Thank you for your help. Can you explain how the head gasket issue
would prevent the generation of a spark at the ignition coil located
on top of the engine? When I did my testing, I left the spark plug
wire connected to the spark plug and removed the other end that
connects to the ignition coil, I held the wire very close to the coil
module and looked for a spark when I turned on the car. The other
five coils that I tested in the same manner sparked. I was thinking
that there is an electrical issue that is preventing the generation of
a spart at the module.

Thanks again,
Tony

"Tony" > wrote in message
...
> Hello Michael,
>
> Thank you for your help. Can you explain how the head gasket issue
> would prevent the generation of a spark at the ignition coil located
> on top of the engine? When I did my testing, I left the spark plug
> wire connected to the spark plug and removed the other end that
> connects to the ignition coil, I held the wire very close to the coil
> module and looked for a spark when I turned on the car. The other
> five coils that I tested in the same manner sparked. I was thinking
> that there is an electrical issue that is preventing the generation of
> a spart at the module.
>
> Thanks again,
> Tony
>
>

that is very hard to see, attach it to a timing light, or just hold it and
see if it snaps ya.
I think you have the dual firing plug things, you may have to replace that
module. (no distributer cap)

Tony wrote:
> Hello Michael,
>
> Thank you for your help. Can you explain how the head gasket issue
> would prevent the generation of a spark at the ignition coil located
> on top of the engine? When I did my testing, I left the spark plug
> wire connected to the spark plug and removed the other end that
> connects to the ignition coil, I held the wire very close to the coil
> module and looked for a spark when I turned on the car. The other
> five coils that I tested in the same manner sparked. I was thinking
> that there is an electrical issue that is preventing the generation of
> a spart at the module.

I mistook the "no fire" comment and it didn't register with me that you
had no ignition fire at the plug. Does the engine in your car have
individual coils for each cylinder? If it does then try and swap coils
between a working cylinder and #2. About the only thing I can think
that would affect one cylinder is a bad coil (if you have six coils),
something wrong with the crank pickup sensor or a computer malfunction.
You have checked the other things I would suspect. Checking the
sensor might be a job depending on where it is located and may require
specialized equipment. I don't know of any way to check the computer
yourself other than to plug in a working unit and see if that solves the
problem. I doubt it is the computer though as those failures usually
mean a dead engine.

have a 1991 mustang 4 cl not firing have changed every thang coils /module/
crank sensor/ computer/ it has 8 spark plugs /i need help with this 1
..have checked all wires car was ruing ,but at times it ran on 2 /cylinder
but know it wont spark at all..thanx

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"noisemaker555" > wrote in message
lkaboutautos.com...
> have a 1991 mustang 4 cl not firing have changed every thang coils
> /module/
> crank sensor/ computer/ it has 8 spark plugs /i need help with this 1
> .have checked all wires car was ruing ,but at times it ran on 2 /cylinder
> but know it wont spark at all..thanx
>

title says you have a 6, in your post you say it is a 4, and has 8
sparkplugs ?

also a 1997 OR a 1991 ?

let us know what you have, and we can help

"noisemaker555" > wrote in message
lkaboutautos.com...
> have a 1991 mustang 4 cl not firing have changed every thang coils
> /module/
> crank sensor/ computer/ it has 8 spark plugs /i need help with this 1
> .have checked all wires car was ruing ,but at times it ran on 2 /cylinder
> but know it wont spark at all..thanx
>
Wow this guy is confused! 91/97 model v6/i4/v8 is not firing all/some of the
time when car is ruing? Maybe it is the extra plugs you have installed in 91
on your 97 model?