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How to temporarily hotwire fuel pump to ignition

2618 Views 6 Replies 2 Participants Last post by  DirtyHarry
Will not have time to properly fix the next day or two. Car cuts off at 35 seconds when the fuel relay kicks off stalling the engine. I suspect it may be the ECU. Heard there is a way to bypass the fuel pump to stay on when ignition is on?
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Try disconnecting the the idle switch on the TPS.
Thank you for the suggestion but unfortunately it made no difference. I'll probably fork over for an ECU at the end of the week, but it is crunch time to be able to commute. I am fairly savvy with electronics, schematics, wiring, etc. I have read several instances where others have temporarily "hot wired" the fuel pump to the ignition.

Just need some help on how to start/identify this fix, unless there is some other component that tells the ECU to shut off at 35 seconds.

Thanks everyone.

85 300ZX 170K
If you were as savvy with diagrams as you claim, you would know from the FSM that you can jump the fuel pump relay located in the RH B-pillar. This is the relay the ECU uses to switch a body ground to the fuel pump which allows maximum voltage.
For the sake of argument and simplicity, lets assume I do not know jack squat about diagrams. From what I gathered I took the wire from pin 20 that goes to the relay and left it hot. Should it have stayed grounded? It was separated from the connector. That did not power the pump. At this point I am at the mercy of others advice, hopefully not condescending, and would welcome a simple step by step method.
Grounding the wire to ECU pin 20 should activate the Fuel Pump Relay which switches a ground to the fuel pump, which should give the fuel pump maximum volts.

Now that I have driven for a bit and had a chill pill to relax, why was it so difficult to find that on a search? It always came back to someone talking about doing a hotwire from the fuel pump to an ignition source with a toggle switch, not something as simple as "ground pin 20" on the ECU. Dude, you are the savior of the day. Thanks!
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