Car won't start, perplexing problem

The car wouldn't start. Put a new battery in, it took a good time to turn over. Car ran 20 minutes no issues.

Next morning, car won't start. Battery is fine, cranks but no go. So suspected fuel pump.

Took it to the mechanic as I can't do a fuel tank, and the new pump burned up. He's had the car two weeks now.

Any ideas? He says I have a short somewhere, but would that cause the fuel pump to burn out?

Year? Is the pass key light on? Can he prove the pump is burnt up or he just doesn't know? If you jump the car at the starter will it run about 5 seconds and shut off?

It's a 94, no pass key. Car won't respond to a jump at all, won't run at all.

All other electrics seem fine.

The guy I brought it to has been doing our cars for 20 years, and he's a good mechanic. I'm sure he's pulling his hair out over it.

Car previously had an issue where I had low fuel pressure and had to crank a bit to get the fuel back up to pressure.

Any ideas?

You can tell if the `pump is fried very simply.

At key on the ECM gives the pump a few seconds to build pressure while it's looking for an ignition signal. You can hear the relay kick in and out from inside the cabin,   If you have someone else do it, you can stick your head under the car and listen for the pump at key on.

Further testing of circuit.

On the left side, Underneath the car, by the rear bumper , is the electrical connection for the pump.

Disconnect it. With a spare battery or battery charger you can run jumper  wires to power the pump.(you'll need to be inventive a bit)

There are three wires. you want the Grey and Black wires. The third wire is for your fuel gaugege.

From your power source, attach plus "+" to the grey, and ground (-) to the black. You should be able to hear the pump whirling aound at that point.

The other way, is that there is a valve on many of the fuel rails near the throttle body so that  a fuel pressure gauge can be attached. It looks like  a little pipe sticking up with a  tire valve stem cap on it. Take the cap off (obviously) and attach the gauge.  Crank it over a few times. You should see some pressure building up.

Perhaps someone else can tell you whatt that pressure should be for TBI vs LT1

Dave

Check the fuel pump wiring in the tank,. they have a habit of failing

I mentioned it to him, he was familiar with it. He is trying new wire to the pump.

Not happy about this at all, it's going to be miserable if I get stuck home on christmas.

also being a 94,. the auxilliary battery post by the underhood fuse box maybe NFG too,.

phantom 309 wrote:

also being a 94,. the auxilliary battery post by the underhood fuse box maybe NFG too,.

Ok I will mention that. Any pic of that around?

It goes here: https://s113.photobucket.com/user/MrCadillac_Magnum/media/Dr%20Buick/Engine10-1.jpg.html

So the end result was a wire under the fuse box had gone bad between the relay and ignition.

The fuel pump wasn't bad but was badly burned up on the contacts and a replaced.

How can I clean the contacts in the fuse box? They are badly oxidized.

Contact cleaner, also called Pot/potentiometer cleaner will work to clean them, I think baking soda and a old tooth brush work well too. If you want to after use a spray on protectant for electrical.