matthewpims

Correct me if im wrong but arnt you suppose to be able to hear the fuel pump in an 84 se run with the key turned to run? I get all the dash lights etc but no fuel pump sound, car runs great too....

Steve Shulz

No, should only run when the engine is turning. (signal off the blue spade connector on the trailing coil). Yours is doing what its supposed to.

Rex4Life

That's close but not the whole story. The fuel pump will run when either of these two scenarios are true:

1) The key switch is turned to the start position.

2) The key switch is in the run position AND the AFM flow switch is closed.

And yea assuming there is power in the battery, wires and fuses are good, and the circuit opening relay is functioning properly.

You can fake out the flow switch by gently pushing in on the flow flapper, doesn't take much deflection to make the switch.

Scott

Steve Shulz

According to the service manual to check fuel pump operation you make sure the terminal U of the trailing coil (blue spade) is connected and ecu main fuseable link is in proper order. There is a bypass terminal (next to the AFM) but the AFM is for the ecu to properly schedule fuel to the injectors not to trip the relay for the fuel pump. If that is the case then why is the fix to a flooded -se is to remove that connector (trailing coil) and turn it over? Please elaborate cause Im just not seeing it (manual or wiring diagram).

hornbm

OK heres how to check. Check the manual, there should be a test connector that you can ground to prime the fuel system. Its either by the airbox or by the drivers side fire wall. I cant remember which one it is on a GSL-SE.

Anyway, its a one wire connector. Ground it, then turn the key to ON. You should be able to hear the fuel pump running. This causes the fuel pump to run at all times.

To unflood the car, you want the opposite. You want to make sure that pump is NOT running.

gsl-se addict

iTrader: (3)

Okay guys,

I will try to clarify this. Rex4Life is correct under which condition the fuel pump operates. Besides these conditions, the AFM switch can be bypassed by jumping the connector with the rubber boot over it next to the AFM. This will cause the pump to run whenever the ignition is in the on position. The purpose of it is so that you can check fuel pressure, injector leakage, etc. without the engine running or cranking. You can achieve the same thing by turning the ignition on and propping the AFM door open.

As for the blue spade connector on the trailing coil, it is used to tell the ECU when to fire the injectors (one injection per ignition event). So, if you unplug this connector to unflood the engine, the fuel pump still runs, but the injectors do not squirt any fuel into the engine.

Some achieve the same goal using a kill switch for the fuel pump. In this case the injectors still try to fire, but once there is no fuel pressure in the line they don't squirt any fuel.

Hope this helps.

Kent

Steve Shulz

Thanks