95 Mustang GT 5 speed with major issues. If the car sits for a couple days it will start right up and drive 5-10 miles with no issues then all of a sudden it will go to running very rich and misfiring. I have changed all this so far: MAF, Coil, plugs, wires, TPS, IAC, IAT, tested fuel pressure(within range), both O2 sensors. I am thinking it is either an ECM or a grounding issue somewhere. Here is all the codes it shows: 113,157,189,543,15. I am at a total loss with what the next step is in the process. I highly doubt its the Distributer or PIP sensor, however there is a small chance it could be. Does anyone have any ideas??

Thanks,

 

sounds like the ignition module on the distributor to me

EDIT: not sure if they still put ignition modules on the 95s. regardless, a bad module will cause a misfire after it warms up. If you want to test it, you could go out there with a heat gun and warm it up while the car is cold. If the car has the problem immediately, you will know that is the issue. you can also visually inspect it by taking it apart.

the computer could also be the issue, it just seems that the way you described, heat has to build up under the hood before the problem starts.

 

if you are sure the car is going rich, check the ground that hooks into one of the bellhousing bolts. It shouldn't cause a misfire, but it will cause the car to run rich. I ran into that problem after a clutch install. I had the wrong bellhousing bolt in that hole, causing the bolt to bottom out before tightening up, thus causing a bad 02 ground

my car has a wieband, so it was easy to spot the problem after the clutch install

 

The 94/95's have ignition modules, but they're located on the passenger side strut tower (under the air box I think, from what I remember back when I had the factory air box) not on the distributor like on the fox's

 

I have a other ICM and swapped it and nothing changed, I would rule that out as well.

 

I plan On looking this week for grounding issues., just been really busy at work. It's been trying with this car for sure.

 

i would start at the battery. more times than not, those cheap replacement $1 leads will break before they are tight. for $5 the ones with steel mixed in with the lead can be had. those can be tightened up

 

The factory ones on the 94/95's suck so bad too, mine would not start at random for the first few months I owned it until I got around to replacing it. Very irritating.