Fuel Pump Power

[FORSFED]

I was under the impression that with the key on, the fuel pump turns on, hence a constant 12V with the ignition......

[FORSFED]

Ok, the way I understand the fuel pumps operation is as follows::

-Turns on for a few seconds with initial key on to pressurize the system.
-Next it shuts off.
-Turns back on while engine is cranking.

I have none of the above happening. I've traced everything back to the ecu and had no luck. The wiring is fine, the MPI relay is fine (can hear it clicking), ecu works, MPI fuse under hood is not burnt out. What does this leave??? I wired it to have keyed on power for the time being, but I'd much rather have it work with the factory wiring like it's supposed to...

[A//// Guy]

Do you have a logger? Try running the fuel pump with that? Otherwise try a different pump.

[LightningGSX]

Originally posted by FORSFED@Oct 10 2004, 05:36 PM
Ok, the way I understand the fuel pumps operation is as follows::

-Turns on for a few seconds with initial key on to pressurize the system.
-Next it shuts off.
-Turns back on while engine is cranking.

I have none of the above happening. I've traced everything back to the ecu and had no luck. The wiring is fine, the MPI relay is fine (can hear it clicking), ecu works, MPI fuse under hood is not burnt out. What does this leave??? I wired it to have keyed on power for the time being, but I'd much rather have it work with the factory wiring like it's supposed to...
Have you tested the output from the ECU? Have you bypassed the ECU and tried actuate the relay directly?

[caustad]

I had a similar problem after my car sat for about a year. It turned out that the ECU fried because of the capacitors leaking while sitting, then I tried to start it and had no fuel pump power. Then when I hardwired the fuel pump like you are thinking the pump turned on but didn't shut off and the injectors sprayed wide open non-stop.

[FORSFED]

Eric, I don't know what wires to test. There are like 3 that connect to the MPI relay according to the diagrams in the manual. What would you suggest I test? I did try swapping a different ecu out of curiosity whether or not that had something to do with it, but I didn't get any different results.

[TsiEagleTalon92]

Back when my dad had the white fireturd steve would remember something broke and the fuel pump was dead he hardwired it too but yea it would be a temp solution except you would have to turn up your idle which basically ruins the point of doing so to me.

[Alpine TSi]

Was that english? Complete and coherent sentences, please.

[TsiEagleTalon92]

Back when my dad had the white fireturd, Steve would remember that. Something broke and the fuel pump was dead, My dad hardwired it. It would be a temp solution except you would have to turn up your idle which basically ruins the point of doing so to me.

Makes perfect sence now..