Fuel pump issues, no power to pump Options

[Tab914]

Hello all,

Well took the teener out today to start my summer driving. Charged the battery and car started on first cranks. Let the car run for a bit, turned it off and turned it back on. Pulled out of the garage and took pictures to get a new insurance policy and let the car sit for half an hour.

Here is where the fun begins. Go to start the car to put it back in the garage and......nothing. Don't hear the fuel pump buzz when I turn the key. Push the car back in the garage and start testing.

The car is a 1974, 2.0lt d-jet.

Direct power to the pump shows that pump works.
Jumping the relay shows that power from the relay board will reach pump.
When pump is running while jumping the relay, the car cranks but won't start.
Then, when checking the main power relay, looks like I am getting no power to the relay board.
Swaped out the computer (brain) for another and still no power to the relay board.
Tried jumping the wires at the relay under the passenger seat and still nothing.


Been going over and over the electrical diagrams and getting nowhere.
Got tired and can't think anymore.

Very frustrating after having the car start right off the first crank.

Is there something simple I am not thinking of?

Thanks in advance to whoever can help. Appreciate all answers / suggestions.

Will check tomorrow after a nights sleep.

Cheers,
Dominic. (IMG:style_emoticons/default/beer3.gif)

[Tab914]

Well after being at it all day I finally got the car running again...... hopefully for a bit longer this time.

After going through alot of the motions again I was finally able to nail the problem. While checking the wiring from the egine bay to the front at the relocation spot, I found the connections to be okay but I touched them up while I was at it none the less.

Doing this allowed me to find out that it was actually the pump that was faulting. When turning the key to the "on" position the pump would sometimes buzz and sometimes not. When it wouldn't after lightly tapping it with a ratchet handle it would buzz. Sometimes it would buzz but not for the full 1.5 sec. and it sounded like it was struggling. Then eventually there was just nothing.

Every time before that I checked it with direct power to it, it would run. But it was in fact the pump that was running intermitently. Unfortunately it took a while for it to fault when I applied direct power to it so it made things confusing. Now the pump would not run at all and I was sure that it was burnt or finished.

Anyway next thing was to empty the fuel tank and remove the pump. With nothing to lose, once the pump was out, I opened it up and seperated the pump part from the motor part. While inspecting the motor I found that the two carbon (I think they are carbon) brushes or post were sticking and not making contact with the middle shaft. They are pushed towards the middle shaft by a small spring each. I removed the two post, cleaned the interior of the small slots the slide in and put everything back together. Now the springs were able to push the post forward and against the middle shaft. Probably a varnish build up from the fuel sitting in the pump all winter. Tested the pump off of the car with direct power and made it pump fuel into a jar. Pump twirled right away and was pumping fine. I was worried the pump might leak once put back together but there are no leaks and pump is running strong for now.

Now the pump is back on the car and does what it should everytime the key is positioned to "on". I just hope it last for a while.

Thanks again to all who helped. Hope this post will help others.

Dominic. (IMG:style_emoticons/default/beerchug.gif)