QuestionQUESTION: The engine died (felt like suddenly running out of gas) in my 1994 1.6L 5-speed manual Geo Prizm (155K miles) and will not start. The battery's good and a jump didn't work. My Hayne's manual recommends I listen for the fuel pump while turning the ignition switch to the "ON" position. I DO NOT hear the pump when I turn the ignition switch "ON." However, I DO hear the pump when I short the Diagnostic Terminal's fuel pump test connectors. I have checked all the fuses and tested both relays and all connectors (except as noted below). I also DO hear the pump when attempting to "START" the engine which based on the fuel pump circuit diagram is expected. I have reached the point at which my Haynes manual states I need to have the ECM diagnosed. I intend to test for continuity from the the ECM to the (fuel pump) open circuit relay and unplug/replug the ECM connectors after I figure out how to get to it. But I'm not overly optimistic that will solve the issue, and I failed to check for engine codes prior to disconnecting the battery (oops)...
Now for a question:
How important to starting the engine is it that the ECM is not priming the fuel pump for a few seconds when the ignition is switched "ON"? Is it REQUIRED that the pump be primed since the starter circuit seems to activate the fuel pump anyway? And, assuming I'm on the right track and the ECM needs to be tested, is there anybody who will test these out of the vehicle? My local Chevy dealer will only test it in the vehicle which means additional towing fees.
Finally, the reason I suspect the problem could be elsewhere is because my car died a month prior the exact same way (felt like suddenly running out of gas), only I was able to jump the battery and get the vehicle home. I had been having problems with keeping the battery charged and assumed that my car died due to a dead battery or bad alternator. Turns out I needed to replace the alternator so I did and the battery has been recharging and everything seemed fine until this most recent malfunction, which as I stated, a jump didn't solve. I don't know if this last paragraph is relevant, but I thought I'd share it all the same.
Any suggestions on what I should do next would be greatly appreciated! Thanks in advance!
ANSWER: The fuel pump does not turn on when the key is on, only while cranking the engine, after that the circuit opening relay takes over to keep the pump running, when using the jumper to activate the fuel pump does it start then? I doubt that the problem is the ECM. If it doesn't start using the jumper, check to see if you are getting spark to the spark plugs while the engine is cranking.
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QUESTION: I have several sources stating that I should be able to hear the fuel pump when I turn the ignition to the "ON" position. If that information is incorrect, then my trouble-shooting to this point likely has been misdirected. I attempted your suggestions and although I could hear the pump operating and afterward, smelled gas near the air intake, I was unable to start the engine using the fuel pump diagnostic terminal. I observed sparks from all 4 spark plug wires using a rubber-handled screwdriver to create a small gap to an engine block bolt. Thank you again for your time and effort.
AnswerOk it sounds like it's getting fuel and no spark, remove the distributor cap and see if the rotor turns when cranking, if so a loss of spark is usually caused by a bad coil/igniter, I think on this one they are inside the distributor, check the rotor and the coil for cracks or arcing.
