No Warning, died overnight

[Mac1947]

1990 Metro. New valves, ran smooth, great mileage. Parked it, next morning, no start. Noticed fuel pump did not cycle when ignition was turned on. Cranked normal, no start.

No pressure in fuel line at throttle body static or while cranking.

No voltage present on pink wire under seat (to fuel pump), Igniton on, cranking starter.

Checked coil on fuel pump relay. Coil pulls down contactor on the bench ok. Not in car with key on or while cranking. Volatge to the coil is present positive side of coil and from the F1 relay. Appears to not be grounding thru the fuel pump relay coil, no pull down.

Cut and grounded negative side of the fuel pump relay coil(socket), key on, power is now at the plug under the back seat to the tank pump.

It appears the computer provides the ground, am I correct? What would happen if I provided a ground to the fuel pump relay so that anytime the igniton was on, the relay was energized (fuel pump energized)? I am thinking bad computer.

Can we make it simple again or not?

[mcalvo]

Can you make a direct test to the fuel pump? Just to be sure there is no energy on the wires that came from the ECU. I recommend taking off the ECU wires at all before test the pump.

Hope this helps.

MC.

[Mac1947]

Hi, There was no power going to the pump (ign on or start). I cut the wire below the socket for the fuel pump relay, wired the socket side of the negative side of the coil to chasis ground. Now running normal.

It appears that the ECU provided ground and either this wire to the ECU is broken or the ECU has failed on just this one port. Getting under that dash is a job for an old guy like me. Everything else is normal regarding operation.

I did not ground the wire going to the ECU since I found somewhere near 50 ohms on this wire. I capped the wire going to the ECU.

In that the F1 relay powers the coil for the fuel pump relay, there is no power to the fuel pump relay until the ignition is on. I will know more in the morning. If my battery is dead and the engine is full of fuel then I was wrong. haha...seriously, I tested the pink wire from the fuel relay to the pump and with the ignition switch off, there is no power on the relay.

I think I will see how this operates and after some time, go back to try to confirm whether the lost ground is ECU or wiring.

I drive a F150. Thats why I am trying to "restore" this old GEO. The 150 gets 14-15mpg while the GEO gets 50-55 depending on the speed I drive it. At near two bucks a gallon here in Indiana, the rest of the story is obvious.

Thanks for your reply.