I have a problem my check engine light stays on even while I'm running the codes it just flashes brighter for me to get the code. I get a code 54 which is low-voltage to the fuel pump could this be why my light is always on I'm also only getting about 14 mpg. I own a 1987 2.8 MPFI firebird any help would be appreciated.

 

If your car still runs i'd bet it is your fuel pump relay. Turn your ignition on and you should hear your fuel pump run for 2 secs then shut off. The oil pressure switch is overriding the relay causeing a "hard start" condition. Nothing to do with bad gas milage though....

 

What about the light staying on even when I'm getting the codes any suggestions.

 

Sounds like a bad ground to the ECM, or a defective ECM, or both. Check all of the ground connections to the ECM for continuity (< 2 ohms) to ground, with the power off.

 

After thinking about it, it may also be the circuit that supplies power to the ECM & fuel pump. Check the voltage at the ECM "hot all the time" (orange) wires, and the power feed (orange) wire at the fuel pump relay, with the car running. The voltage should be around 13 - 14 volts. The 20 ampere in line fuse near the battery supplies power to the fuel pump & the ECM. If the voltage is low, check the wiring from the fuse to the ECM / FP relay / FP oil pressure switch. The fuel pump is controlled by the fuel pump relay and the fuel pump oil pressure switch. Both are in parallel, so it is not too likely that either the relay or the oil pressure switch is defective.


Tim