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)

[swl]

Hey Dominic, I just went over your other post about your fuel pump surging and noticed that your pump has been relocated to the front. That means that your wiring has been hacked. Probably a pretty good hack since the pump is still using the proper fuel pump power from the relay board. I'm willing to bet that your problem is somewhere in that wiring hack and the problem you are seeing now is just the surge problem getting worse. Before you do anything else with the relay board you should find the join between the original wiring and the 'extension cord' up to the front. I'll bet if you stress that joint a bit it will fall apart - just making marginal contact and as you do your troubleshooting you are moving the wires enough that the contact returns. The original wire comes out of the harness up in the front right corner of the engine compartment then passes down through a grommet to the original location. This is pretty much right under the ecu. Your joint is probably right there.