DFI and ECMDiscuss all aspects of DFI (Digital Fuel Injection), ECMs (Electronic Control Module), scanners, and diagnostic equipment. Fine tune your Third Gen computer system for top performance.
Welcome to ThirdGen.org!
Welcome to ThirdGen.org.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!
Hello, guys, New to the site, and I just acquired a 91 Firebird 305 tbi. It came with the issue of the fuel pump not wanting to run. The po had wired in a toggle switch to the pump relay and hot wire to get power to the pump so it would run. I found a thread talking about replacing the transistor in the ecm. But, I have to admit, its greek to me. Which one is it in the ecm? And where can I find the replacement transistor, and with what kinda part #? Sorry to be a newb, just not much of an electrical genius. Thanks in advance!
You may want to test the output to the relay at the ECM first before assuming its bad. The pin on the ECM that controls the relay is pin A1 (see pinouts below). With the engine running the ECM should provide battery voltage to operate the relay. If it doesent, than its probably easiest to just replace the ECM with another. If battery voltage is present, than it may be the relay itself, or the circuit.
Well I tested the Voltage on the pin for the fuel pump driver(dk grn and whitewire) with the car running.It showed 13.8 volts. So obviously it isnt the ecm. I guess the relay is next in line.
