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Help.. Any thoughts.. fuel pump wont stop running..

Dynamic Duo

Dynamic Duo

New Member
I have a 1991 LX Coupe 5.0 liter. Most recently I replaced the ECU due to fuel pump continuing to prime and vehicle not starting. After trouble shooting I was able to narrow it down to the ECU. Bought a replacement while verifying vind #. type of trans. and all specs. for correct ECU replacement.. Installed New ECU ( used ) and car started right up ran fine for a few months. Then I noticed most recently when I drove the car the other day that even though the car starts, runs, and drives fine that the fuel pump continues to run as I noticed a slight change in my amps reading under 14 volts because it continues to draw power. Before I start pulling my hair out again lol I just reaching out to see I anyone had any suggestions... Thank you..
 
broncojunkie

broncojunkie

Well-Known Member
When you say the fuel pump continues to run, I presume you are talking about key on/engine off? I realize that's what was going on before changing the ecu. But reading your post, I'm trying to figure out if the same thing is happening now (except that the car will actually start and run).
 
Redtwilight

Redtwilight

Shinigami
Dynamic Duo said:
I have a 1991 LX Coupe 5.0 liter. Most recently I replaced the ECU due to fuel pump continuing to prime and vehicle not starting. After trouble shooting I was able to narrow it down to the ECU. Bought a replacement while verifying vind #. type of trans. and all specs. for correct ECU replacement.. Installed New ECU ( used ) and car started right up ran fine for a few months. Then I noticed most recently when I drove the car the other day that even though the car starts, runs, and drives fine that the fuel pump continues to run as I noticed a slight change in my amps reading under 14 volts because it continues to draw power. Before I start pulling my hair out again lol I just reaching out to see I anyone had any suggestions... Thank you..
Click to expand...

How old is the pump? It could possibly be the pump itself going bad. Also check the relay for the fuel pump.
Lastly, since it is a used unit, you could pull the ECU, remove the cover, and check for any corrosion or bad spots on the circuit board. Usually the capacitors will start to leak and corrode.
 
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