Please help diagnose my problem!!!!

[mayday]

I have a 2001 GT and as of late it has been miss firing when it is under a load, but only when in between 1000 and 1500 RPMs. I believe that it is electrical, but I am not sure of how to isolate the problem. I thought that a spark plug had fouled out so I changed them all to NGK's, but the ones I took out looked fine. I even changed the coil-on-plug pack to the Granatelli aftermarket packs. I am not sure how to check the PCM (EEC) or at the moment even where it is on the car. If anyone has had this problem let me know how you fixed it.
Thanks,
Mayday

[MAXSTANG]

Originally Posted by mayday

I have a 2001 GT and as of late it has been miss firing when it is under a load, but only when in between 1000 and 1500 RPMs. I believe that it is electrical, but I am not sure of how to isolate the problem. I thought that a spark plug had fouled out so I changed them all to NGK's, but the ones I took out looked fine. I even changed the coil-on-plug pack to the Granatelli aftermarket packs. I am not sure how to check the PCM (EEC) or at the moment even where it is on the car. If anyone has had this problem let me know how you fixed it.
Thanks,
Mayday

You getting a code?

[mayday]

I checked tonight and there are not any codes in the computer.

[Santo]

compression problem mabey?

did you try the plug wires?

[bill94gt]

clean off the mas with throtle body cleaner had a friend with a simlar prob and that fixed it

[MAXSTANG]

Originally Posted by Santo

compression problem mabey?

did you try the plug wires?

Thats what I was thinking. It might be your plug wires. Also check the connections on the distributor where they connect to the cap.( little metal things on the inside.)

[mayday]

I don't have spark plug wires. I have the coil-on-plug setup. However I did check those too and they all seem to be working.

[Santo]

Originally Posted by mayday

I don't have spark plug wires. I have the coil-on-plug setup. However I did check those too and they all seem to be working.

yea slipped my mind that mod engines are distributerless(all i work on is pushrod motors) but anyways...
if you havent already found out the problem... do what bill94gt said and clean the maf sensor and the o2 sensors. what octane are you running? try using the next level octane next time you fill up and see if it runs better, which if your running the reccomended octane could be a bad thing being that it sounds like your car is just a mild tune. My tractor (yes tractor) was misfiring on 1 & 4 cylinders. but before i knew that i upped the octane thinking it was just some crappy gas and it ran better. and it turns out i had very little compression in those cylinders, so in order to keep those cylinders firing correctly it needed a higher octane. keep in mind that this is a old pushrod 4banger from the 60's so it might be a different story with the mod motors.

[mayday]

Originally Posted by Santo

yea slipped my mind that mod engines are distributerless(all i work on is pushrod motors) but anyways...
if you havent already found out the problem... do what bill94gt said and clean the maf sensor and the o2 sensors. what octane are you running? try using the next level octane next time you fill up and see if it runs better, which if your running the reccomended octane could be a bad thing being that it sounds like your car is just a mild tune. My tractor (yes tractor) was misfiring on 1 & 4 cylinders. but before i knew that i upped the octane thinking it was just some crappy gas and it ran better. and it turns out i had very little compression in those cylinders, so in order to keep those cylinders firing correctly it needed a higher octane. keep in mind that this is a old pushrod 4banger from the 60's so it might be a different story with the mod motors.

I cleaned the MAF sensor and all I have run in it since I got it new is premium 93 octane gas. I also cleaned the IAC just for good measure. I am going to try changing the cam and crank sensors, because now the car won't even start. I did check the compression on all the cylinders, and they are all at 180 or so. While I was doing that, I checked the plugs and they looked fine. Anymore good IDEAS anyone?????? I am desparate. Thanks to all that have tried to help.

[kev_94gt]

It sounds like your pcm is shorting out and sometimes the pcm wont show codes when it a going out. good luck