Fuel Pump Frustration Options

[dcheek]

I have a bone stock 24000 mile 1976 914 2.0. Owned it since new. It's been sitting for a while. I started it up and let it idle, which it did for about 5 minutes, then quit. I cranked and cranked and it would not start. I had a buddy spray some starting fluid and it would run as long as he was spraying. So, it must be a fuel problem. I removed the fuel pump, hit it with a plastic head hammer and it started. I drove home to do some maintenance and, after parked in the driveway, it would not start again. I tried the hammer routine without any luck. So I figured the fuel pump is toast.

I just installed a new pump and fuel filter and drained all the gas out of the tank. Before I buttoned everything up I turned the key to see if I could hear the pump "spool up" for the second and a half that the computer tells it to........nothing. I disconnected the pump leads and hooked it up to a separate battery and the pump spins. Then I hooked up the pump again, turned the key and nothing, no spool up. I hooked a test light to see if I'm getting voltage when I turn the key, and yes, the test light goes on. Then I hooked up a separate ground wire to the negative terminal of the pump and grounded to the chassis, turned the key and it spooled up.

Is this a symptom of a faulty fuel pump relay or is the negative wire to the pump is bad, or both. Or is this a problem with the computer control unit. Incidentally, I swapped the voltage supply relay with the fuel pump relay, since they are the same, but that didn't seem to make any difference.

Frustrated,
Dave

[Tom]

Sounds like your problem is with the ground. Common for these cars. I'm not sure where the ground connection is for the fuel pump, maybe someone else can tell you. You need to remove the grounds from the stud and clean them and reattach. I'm sure there is one in the front trunk somewhere. Look for brown wires connected to a stud.
Tom

[dcheek]

Sounds like your problem is with the ground. Common for these cars. I'm not sure where the ground connection is for the fuel pump, maybe someone else can tell you. You need to remove the grounds from the stud and clean them and reattach. I'm sure there is one in the front trunk somewhere. Look for brown wires connected to a stud.
Tom

Tom,
Thanks for posting. The ground (or lack of ground) must be the problem since adding another remote ground wire worked. I traced the wire, and of course it's buried to the far right where the fuel pump mounts. I removed the spade connection a couple of times to see if that would improve the contact. Of course that didn't work. I will have to remove the outlet lose to the pump to see if I can clean up the connection to the chassis. I will also test the ground wire to see if it is okay. IF all else fails I will run another ground wire to a new location. I'll keep you posted.

Dave

[D1A3]

I had a similar problem with my '76. Quick fix was to rewire the power and ground. My ultimate fix was to get a new relay board.

Yes, I traced every wire, tested and retested everything. Replacement of the relay board was the only thing that worked. However, check the multi-spade ground below the relay board. I seem to remember that there is a ground there that might influence the pump's operability.

I have also had a recurring issue with the factory original pump overheating at AutoX's on the hottest of days. In those cases, a quick pour of some ice cold water usually does the trick. I've had several folks suggest replacing the pump, but have yet to get around to that.

Good Luck!

[dcheek]

Well, today I completely removed the original fuel pump ground wire. I checked continuity on a VOM and, guess what? The wire was completely dead! So, the ground to the chassis was fine, it was the actual ground wire that was bad. I cut off the connectors and soldered on new ones. The pump spooled up 1 1/2 seconds when you turn the key and the car started right away. As with any backyard mechanic repair you learn something every time. Now, with electrical problems, I will check the ground FIRST.

Thanks to all that gave me suggestions on how to solve my problem. Here is a picture of my car after washing today and tucked away in the garage. Next week I will be changing all the fluids; oil, brake etc.

[swl]

bravo!

and well done with keeping your car in such great shape. Not easy to do in the north east!

[jonferns]

bravo!

and well done with keeping your car in such great shape. Not easy to do in the north east!

It's because it never gets driven (IMG:style_emoticons/default/poke.gif)

[dcheek]

bravo!

and well done with keeping your car in such great shape. Not easy to do in the north east!

It's because it never gets driven (IMG:style_emoticons/default/poke.gif)

Hey, I'm averaging 685 miles a year! LOL.

Dave

[Spoke]

Good job.

About the test light test you did where the test light lit up but the pump wouldn't turn: As you found out, the ground wire was bad.

The test light worked because it is a high resistance (low current) and the bad wire (also high resistance) allowed enough voltage across the light to light it up.

The best way to test is with a voltmeter across the terminals with the pump installed. Test lights won't necessarily show a drop in voltage. in the wiring.

[Jasfsmith]

bravo!

and well done with keeping your car in such great shape. Not easy to do in the north east!

It's because it never gets driven (IMG:style_emoticons/default/poke.gif)

Hey, I'm averaging 685 miles a year! LOL.

Dave

Come on Dave. Drive that beauty. Hell I did that mileage last weekend....

[JawjaPorsche]

Nice looking 76. I can tell it is your pride and joy!

[76-914]

I'm no genius but in my experiences the ground is the guilty culprit 90% of the time. Electricity is always searching for a ground.

[dlee6204]

Nice car! (IMG:style_emoticons/default/drooley.gif) Glad you got it fixed!

[dcheek]

bravo!

and well done with keeping your car in such great shape. Not easy to do in the north east!

It's because it never gets driven (IMG:style_emoticons/default/poke.gif)

Hey, I'm averaging 685 miles a year! LOL.

Dave

Come on Dave. Drive that beauty. Hell I did that mileage last weekend....

I do plan on driving it more, well, not as much as you! I forgot how much fun these cars are to drive!

Dave