Misfiring even after replacing coils

[Sadimsosad]

2015 Ford Mustang GT. 48,000 miles.

Catless long tube headers and tuned on E85.

Warmed up car and drove 30 seconds before I got a p0351 and p0354 code. Replaced all 8 coils and plugs which were gapped at .030 from the car previously having a Whipple blower on it. New plugs gapped at .050 .

Still have the same codes.



Checked for constant 12v at coil - ok

Checked continuity between coil and PCM - ok

Checked for spark - ok

Checked for fuel injector power - ok

Checked for fuel injection signal - ok

Check for blockage in injector - ok

Re-flashed E-85 tune file - no change

Flashed 93 octane tune - no change



I can’t tell whether or not it has E -85 or 93 octane in it

Sponsored

 

[engineermike]

Time for a compression test.

 

[WildHorse]

2015 coils are different from the 16-17 coils. Make sure you got the right ones ;)

 

[Sadimsosad]

Time for a compression test.

Would bad compression show ignition coil codes?

 

[Cobra Jet]

Malfunctioning IMRCs as well as the VCTs will cause misfire codes too.

Also, I don’t know if it will help, but attached is the Misfire diagnosis from shop manual:

 

[Jackson1320]

What plugs are you running. You might try bringing the gap down a little

 

[Sadimsosad]

2015 Ford Mustang GT. 48,000 miles.

Catless long tube headers and tuned on E85.

Warmed up car and drove 30 seconds before I got a p0351 and p0354 code. Replaced all 8 coils and plugs which were gapped at .030 from the car previously having a Whipple blower on it. New plugs gapped at .050 .

Still have the same codes.



Checked for constant 12v at coil - ok

Checked continuity between coil and PCM - ok

Checked for spark - ok

Checked for fuel injector power - ok

Checked for fuel injection signal - ok

Check for blockage in injector - ok

Re-flashed E-85 tune file - no change

Flashed 93 octane tune - no change



I can’t tell whether or not it has E -85 or 93 octane in it

Found that I was looking at the wrong coil. I was looking second from the drivers front and it was 4th from passenger front. Found that the coil had melted because it was getting a constant ground from the pcm So the coil was overheating.

 

[WildHorse]

Found that the coil had melted because it was getting a constant ground

and why was it getting a 'constant ground'?

 

[Sadimsosad]

and why was it getting a 'constant ground'?

I unplugged the pcm connector and it lost ground. I tested the wire between the coil and pcm and it’s got good resistance with no continuity to ground until I plug it in on the pcm side. These coils have a constant 12v from ignition in one side and the other wire should be a ground pulse that the pcm makes internally, so constant ground means failed pcm I think

 

[WildHorse]

means failed pcm I think

See post #3.

 

[Sadimsosad]

See post #3.

Don’t think it’s an issue caused by the wrong coil because it is the same cylinder misfire before and after replacing coils. Also cyl #4 is the only one with a constant ground on the signal wire

 

[Cobra Jet]

You might want to check this other thread regarding melted coils - you’re not the first:
https://www.mustang6g.com/forums/threads/dtc-code-p0354.145419/#post-3112309

Sponsored