94GT Fuel Pump Won't Prime

[phatstang]

While driving and taking a corner at around 15 my car just died. It would crank but would not start. I noticed I could not hear the fuel pump prime when i first turned the key to on. I checked the cutoff switch and it was not triggered. Once I got my car home i jumpered the fuel pump test connector and still could not hear the pump run. I decided since I still had the original pump in mine I would go ahead and change it. I dropped the tank and unplugged the electrical connector to the fuel pump. I decided to try and test the new pump so I fished it up into the trunk and plugged it into the new pump. I turned the key and could not hear the pump run. I jumpered the test connector and still nothing. Is this a valid test? Does the pump have to be in the tank to run for any reason?

If the new pump should have come on the next thing I am going to try is test the voltages in the pump circuit starting with the cutoff switch and the CCRM. Any other suggestions?

 

[phatstang]

Should the pump run with just the electrical connector hooked up and the pump not in the tank?

 

[toyman]

I would think so. Try running a temporary power lead from another point to see. If it turns on and I expect that it will you'll need to work back along the circuit to see where the power ends. Grounding the FP lead at the DLC will allow the pump to run continuously with the ignition switch on. It's the pin on the short side of the diagnostic link connector (DLC).

 

[five0xpres]

You might want to double check and make sure the inertia switch in the trunk hasn't been tripped. It's behind the trunk liner on the driver's side near the turn signal housing. There is a button that you just press to reset it. You can also use a test light or voltmeter to make sure there is power on both sides of the switch, since that circuit is the direct power line feed to the fuel pump inside the tank.

If possible, you might also want to pull any codes. When my fuel pump failed last month, I got a code 542, indicating a problem with the fuel pump and the ECA to motor ground connection.

Good luck.