mathesar

Car has 94K miles and is currently all stock (other than a centerforce clutch).

For the past few weeks after the car warms up it starts to misfire especially when accelerating from a stop, If I go WOT it just refuses to accelerate properly (sputter / loss of power) or even just taking off normally will cause symptoms but its worse WOT, no popping sounds or backfiring from exhaust that ive noticed.

Also when I come to a stop sometimes the idle will drop down pretty low and then resume normal idle a few seconds later (only does this after warmup).

I'm not sure where I should start and don't really have a lot of $$ to start throwing parts at the car, Ive researched the symptom and get all kinds of results, a bad coil that's failing under load, maf sensor failure, iac valve, intake leak etc.

I'm curious where you guys would start looking considering symptoms.

So far I've:

Pulled each coil and checked for cracks on the boots and made sure cylinder wells were dry (All good on both).
Made sure battery is healthy, multimeter reads 12.1V in the morning before starting car, 14.90V right after starting.
Cleaned MAF sensor with CRC maf cleaner.
Checked for trouble codes with my scanner, so far its showing 0 pending and 0 codes.

I haven't pulled any spark plugs only because I'm a little intimidated by the process on these cars (ive done it once, changed plugs 2 years ago) and I didn't think it would be a plug issue considering it runs fine when cold, but if you guys think I need to check plugs I will.

Thanks.

builtrite

Mine was doing the same thing I called my buddy who I call the 'mustang whisperer' he said replace the #4 coil. I doubted him right up to the time that I replaced the coil. I'm not sure if it would fix your issue since normally they throw a code. Just something to consider.

mathesar

Thanks looks like it might be a bad coil after all, I finally got a check engine light and its reading P0302 cylinder 2 misfire, I ordered a new motorcraft coil hopefully it does the trick.

I'll post results when I get the part

mathesar

I installed the new coil yesterday, Car has been running great since then even after warmup so I'm a happy camper, Really glad that annoying hesitation / sputter is gone.

Thanks.