94 tbird fuel problem v6 (need help fast!)

[94tbird]

Hey everyone,

Got a 1994 bird that won't start. The fuel pump is not working. It has been replaced and it still won't work. We replaced the pcm today and it still won't work. Checked the inertia switch with a meter and it is fine. The bypass mode with the DLC doesn't even get the fuel pump to operate. Is there a fuse that I don't know about or something. I am using a Haynes manual to help me diagnose this and it has me running in circles. Any ideas?

Thanks in advance.

[Notorious_Ford_Guy]

there is a relay in the power distirbution box under the hood that control the power to the pump,
i would check that

[94tbird]

Thanks Notorious,

I will do that. Do you know if the sending unit is self grounding or does the gas tank and sending unit need to be fully in the vehicle to have a complete circuit? Thanks again for your reply.

[fordforlife]

this may sound stupid, (but i did it, so)when i replaced my fuel pump in my 93t-bird, i forgot to hook the wire harness back up. The one that is outside of the tank, under the car. I turned the ignition on and it said the tank was full (it was empty) so i knew something was wrong.

[94tbird]

Thanks Fordforlife.

Doesn't sound stupid at all. Stuff happens, especially when you are working on cars. The only one I know of is the one that goes directly into the sending unit and I never unhooked it. Just disconnected the negative side of the battery to be safe.

Thanks for the reply.

[fordforlife]

oh-ok, sorry i cant help ya anymore. when u turn the ignition on, the pump doesnt make a sound at all right? no little whirring sound or light hum?

[94tbird]

Nope,

It doesn't do a thing. Thanks for the reply though.

[flewthecoupe]

It might be time to start checking for voltages along the power wire to see if you have a disconnected or broken wire.

[94tbird]

That was one of the weird things. I checked the voltage at the pump wires and it was just over 10 volts. I found that to be odd. Man, I hope that this isn't a broken wire..... Thanks for the reply.

[flewthecoupe]

Poor ground or a bad pump?

[94tbird]

The pump is new and it works if I hit it with a battery charger. Not sure about the ground. I asked previously if the sending unit was grounded through the wires it is connected to or if the unit has to be in the vehicle to get proper ground? I'm starting to think this is gonna be wiring. I am really starting to despise this car. Thanks for your reply.

[88v85LT-bird]

have you been in an accident or been off-roading recently? jolts to the impact switch set it off and that turns the fuel pump off which may be your problem.

[94tbird]

No accidents or off-roading. The inertia switch is functioning properly, I checked it with a meter.

Thanks for the reply.

[discipled1]

Hey, just a thought... you might want to check the manual shut-off switch on the left side of the inside of the trunk. It may need to be reset. Also, check error codes on the computer. I'm guessing, but the fuel pump only energizes for a brief time during start-up when the key is turned on. It may take several twists of the key of off and on to get pressure up, it it works like another car I have. If all else fails, manually supply voltage to the pump and get pressures up, and start the car. Disconnect the manual jumper wires, and reconnect to system wiring, and restart the car and check for opperation (the car stays running). If you have a light, you can put that on the pump to monitor when it's being energized.

P.S. the 10V DC could be poor contacts in the circuit due to the old pump drawing too much amps. So, look for a relay that is bad at the contacts with an ohm meter, or just replace the fuel pump relay if 12v are going in and only 10 are coming out.