Not to flame but the problem that was discribed is very common among FORD TFI systems. If the TFI is bad it will not send any codes. Granted the ECC will store code without a CE light but most of those codes are not faults that will kill the engine. If you go to the www.corral.net you will have a code de-coder and allthe instructions to run the Key on engine off diagnostic as well other good information.<br><br>Allen

Any good shop can tech that for you quickly, but I would expect the idle motor or idle motor circuit is faulty. Do you have any friends with good handheld diagnostic tool?

first thing I`d invest in is a ford code reader and check the computer for stored codes my guess is you have a bad TPS (throttle positioning sensor)but the best way to check is the codes good luck

I'd second the previous suggestion of a code reader (~$30) and checking the TPS (It should read just under 1 VDC with the engine off and the key on accross the green and black wires). <br><br>You mentioned that the A/C was on. I would look at testing the A/C clutch and/or compressor. If its engaging or disengaging hard it might be slowing down the engine to the piont of stalling. When you turn the A/C on the computer is suppose to up your idle rate to compensate for the added load on the engine, but if the A/C is messed up.... you see where I'm going. Good Luck.

If you are not getting the check engine light the code reader will not help. What it sounds like is the TFI module is bad. This is the grey module on the distribtor. The AC being on doesnt matter except it will add to the heat and this may be too much heat for the TFI. I would replace it but if you get a new one get a FORD one . Aftermarket ones tend to fail a few months later. A good site for info is www.corral.net Good luck<br><br>Allen

the ECM will store codes without check engine light coming on. a jumper wire is all thats needed to give you stored codes by blinking them to you with check engine light

$10 or so will get you a code book at auto parts store and it includes instructions to jumper self test connectors. allways check your computor codes first cause its so easy, then look for non electronic problems

Modern cars are complicated systems making troubleshooting impossible unless you take the time to use this complexity to help you. With a simple jumper wire it will tell you in digital language what is wrong with itself. If you are a Mustang hobbiest take the time and spend 20 bucks and buy a code manual. Your local auto parts store should be able to hook you up with it or check J.C.Whitney or a book store for Ford Fuel Injection & Electronic Engine Control by Charles O. Probst, SAE, Robert Bentley Publishers.<br>A simple code check will tell you if you have electronic problems or mechanical problems. You can't fix a problem you can't find. Bob.

Not to flame but the problem that was discribed is very common among FORD TFI systems. If the TFI is bad it will not send any codes. Granted the ECC will store code without a CE light but most of those codes are not faults that will kill the engine. If you go to the www.corral.net you will have a code de-coder and allthe instructions to run the Key on engine off diagnostic as well other good information.<br><br>Allen

Any good shop can tech that for you quickly, but I would expect the idle motor or idle motor circuit is faulty. Do you have any friends with good handheld diagnostic tool?