I have a 1987, 744 Turbo. Because it was over fueling, blowing black smoke out the exhuast, it has sat for about 3 months. I had to replace the battery because the battery was dead and would not hold a charge. I read information on the site about the fuel pressure regulator and have since replace the fuel pressure regulator. I have checked the fuse it was fine, and still replaced it. I don't hear the main pump when I turn the ignition on however. The car has been parked in the driveway ever since, and had start fine until the batter went dead. Short of putting a new main fuel pump, is there anything else I can do before replaceing it?

JamesDad

If your having excess fuel problems you may look at this fix I did to mine:
http://www.brickboard.com/RWD/index.htm?id=486629
Jeremy

first test to see that you have a spark, then test for presence of fuel pressure.

second try the fuel pump relay located behind the ashtray. put your finger on it and turn the key on you should feel a click.

third try the noise suppresion relay located under the hood on one of the shock towers, once again it should click when powered up.

third above the battery on the fender is a group of resistors that are fragile(4 resistors in an aluminum case (about 1 1/2 x1 1/2 x 3), usually with 5 green wires
this may have been bumped when changing the battery. It controls the injectors, if you have spark and fuel pressure make sure that all the wires have continuety.

Hope this helps

Merci

Yvan
--
65 122s/73 1800es/80 262c(350ci v8)/89 745t/87 780/89 740/89 740t/ 86 745 and too many parts cars and projects to list

Hi Yvan:
I also have a 740 (88 non-turbo) that won't start.

I have tried repacing a lot of parts , incl. AFM, ECU, power stage, dist cap coil, fuel filter ( I had spares that I knew worked ok) with no success. Seems that pumps are working ok but injectors are not putting out enough gas to start. It did run for a wjhile last weekend but then mysteriously quit again and wouldnt restart, so I'm searching for a loose connection or ground in the injection. However, I can't find any group of resistors or an aluminum case near battery that you have described. Do you think that an 88 or a non-turbo would be different ? Any other location that you know of? thanks for your knowledge contributions. jim dunne