1988 Mustang GT Stalls with Throttle Apply

Kaline

Kaline

Forum Member
I am helping a friend and figured there are some experienced Ford guys on this forum. A friend of mine is building a Factory Five Cobra, using a another friend's wrecked 1988 Mustang GT as a donor (speed density EEC-IV system). The engine is 100% stock and ran fine in the donor Mustang before it was pulled. The transmission is a T5 manual. Both are now installed in the Cobra and the engine starts, but stalls once the throttle is applied. I am trying to help him trouble shoot it (blind leading the blind, as neither of us have much experience with troubleshooting FI).

The fuel pump, fuel pressure regulator and Maniford Air Pressure (MAP) sensor are new. The Throttle Position Sensor (TPS) appears to work fine, based off probe testing. I suggested he replace the Thick Film Ignition module on the distributor, incase it is getting flaking.

Does it sound like an engine management problem or a wiring problem with the harness? We are not ruling out a wiring problem, as the OE harness was salvaged from the Mustang and modified to fit the Cobra. He does not think he crossed two wires, but a reversed signal could be our issue.

Any advice is appreciated.
 
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Clean the TB, TPS and IAC, check for Vac leak. Fuel pump relay? Timming.

Plug a scanner into it also.
 
he said speed density car (no maf) , so possible vaccum leak ? check with carb or brake clean to find leak, also like said before iac ?
 
I had 1 with a bad pick up in the dist. Acted weird would idle poorly but no accel. Would also backfire. Poor spark. Not the Tfs module.
 
I've had a similar issue in the past w/my 5.0 which turned out to be a bad EGR sensor (not the metal valve, but the sensor on the back). Can you pull codes?
 
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