Fuel pump runs non-stop when ignition in "on" position *solved*

[Ether-D]

1992 m20b25, eaton m90 supercharger, and Whodwho ms2 has been running great for 3 weeks since I installed the s/c. …but…

Usually, when I turn the ignition to the on position, I hear the fuel pump run for a few seconds and then it stops. Lately, it won't stop running and the car won't start. Sometimes it will turn itself off and when it does, it starts fine. Relay? Pump? Any ideas guys? Thanks in advance.

[FLG]

sounds like a relay issue, could try swapping the dme and fuel pump relays and see if it still does it.

[Ether-D]

I'll start out in the morning with that. I have the pump out to look it over. Thanks bro.

[nando]

sounds like a relay issue, could try swapping the dme and fuel pump relays and see if it still does it.

You cant swap the FP and main relays, they are different.

[Ether-D]

Does anyone know why the fuel pump turns on for a few seconds then turns off under normal conditions? Does it have some kind of pressure switch?

[Ether-D]

Solved. It was the white, 5-prong relay in the bank of three on the strut tower, driver side. You were on to something FLG. When you turn the ignition to on, it should go "click…clickyclick" then the fuel pump will shut off. Mine was just clicking once, and no shut off.

[FLG]

Glad you solved it. Yeah just remembered the main relay is 5 prong and thing FP relay is 4?

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[Ether-D]

Glad you solved it. Yeah just remembered the main relay is 5 prong and thing FP relay is 4?

Correct. Thanks again.

[gettinscurvy]

So it was the main relay that needed replacing?

My car just developed this issue yesterday, Ignition "ON", fuel pump runs non-stop, whereas last weekend it was operating as designed (Ignition "ON", fuel pump runs for 1-2 seconds).