pyscho7

I just checked timing and you can see a clear misfire in the leading coil at idle. I am assuming this is why my car is misfiring up around 5500 rpms as well. I have replaced the leading coil once with another used coil...and it seemed to fix my problem for about 10k miles. is there a better solution to just replacing it with another coil? I can't say I've ever looked at aftermarket ignition components for the 7 as I don't ever plan to have more than 325 whp and I could of sworn I read somewhere that they were already decent units. But this can not keep happening.

AFR's stay about 11.7:1 and then right at 5500 it backfires or misfires and you can see it goes lean, I am assuming that its just raw gas touching the wideband sensor as I am running 10psi and its fine all other times. Maybe this is more of a rant than a question, but this is a awful problem that needs to end.

pyscho7

OK got ahold of a different leading coil as well as some cheap spark plug wires to test both, which it still misfires.

What else could be responsible for a misfire like this? CAS? TPS? fuel pump seizing? I put a timing gun on it and I can clearly see a misfire only on the leading coil.

J-Rat

iTrader: (2)

How do the plugs/wires look?

pyscho7

I did a resistant check on the wires, magnecore 10mm wires, the leading wires were around 6k ohms, the trailing was like 4.5? I cant remember, but they were consistent with trailing and leading sides, I went ahead and got some cheaper plug wires just to test it out, as I said, replaced the leading coil just as a test, still problematic. One thing that I noticed has changed is it idles higher. I idle around 13.8-14.0 afrs, I don't know if thats rich upon idle or not, but you can hear it misfire at least once per 7 seconds, then of course the major one at high rpm, gas mileage is about a steady 19 mpg, fuel filter is changed, spark plugs are pretty new, replacing them tomorrow just to be sure, its killin me.

pyscho7

was looking at timing today, spotted something new, if you open up the CAS cover, the leading coil is firing on either plug where its supposed to as well as about 90 degrees apart, as if there is an interruption.