Fuel System/ECU Help! PLEASE!
 

I have an 1989 LX 5.0 Coupe. Problem is when I turn the key on without starting it even, the fuel pump keeps running. The injectors are also injecting fuel to the motor. It will start but, it blows some light black smoke, bogs down, stalls, and if I try to drive it, it won't go over 1500 RPM, even on the floor. It just jerks and hesitates. Also, there is a popping noise coming from the engine, I think its intake backfiring. After it started this it did it for about 2 hours, then drove normal for about 15 minutes, then started to do it again. It finally died on me and wouldn't restart, so I replaced the ignition control module, and it started. But it continued to hestitate, jerk, and smoke. PLEASE HELP. I have replaced the Throttle Position Sensor, Ignition Control Module, Fuel Pressure Regulator, and the fuel pump is a couple months old. Next guess is the ECU. I'm open to any suggestions! Thanks The check engine light is also on, and I tried to use a code reader on it, but it wouldn't work.

Check your ACT sensor. It's on the driver side of the lower intake just forward of the plenum. It's kind of angled and has a big round connector going to it. Mine got fouled once and had similar symptoms.

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351W 89 Mustang GT Convertible