Spidey944

when you are testing for power at the fuel pump connector, are you cranking the car?

potent951turbo

Yeah, there is no power during cranking or just sitting with the key on.

phlip

Do you have 12 v at terminal 30 of DME relay? If yes, and jumping 30 to 87b
does not give you 12v at fuel pump harness the you have an open. Next thing I'd do is use a ohm meter and some long jumper wires to test continuity from relay socket to fuel pump harness connector. I dont think there is anything between terminal 87b and pump harness, but it has been a long time since I looked at a diagram of that . Hope this helps.

potent951turbo

I will double check for 12v at terminal 30, but I am pretty sure its there because when I put the jumper in place it causes the waterpump for the turbo to kick on.

phlip

I think you may be checking at the wrong relay socket. The wiring diagram I have shows a seperate relay for turbo coolant pump.

potent951turbo

No its definately the DME relay as I am very familiar with it from my other 944's and diagnosing problems.

potent951turbo

Update- Well I was finally able to get the time to work on the car. When I first got the car I opened the DME up and it looked like an explosion had happened on the circuit board and it was burned black. However after switching the computers the car still would not start and the fuel pump was not coming on, so I switched it with what was a good spare pump last time I had used it however that didn't change anything so I figured something else must have been wrong and wasted many hours testing other components. So last weekend I got someone to crank the car while I had a volt meter hooked up at the fuel pump and sure enough there was power back there but no pumping. I bench tested both the fuel pumps and neither of them would pump all they would do is give a slight jolt and stop, so my spare must have gone bad from sitting on the shelf. Today I installed a brand new fuel pump and filter and the car fired up for the first time in over 2 years.

The PO said the car just shut off on him and wouldn't start up anymore so it sat for about two years before I bought it this fall. My theory is that the DME must have gone bad, and then the fuel pump must have frozen up from sitting so long. So now the real ordering can begin with new front seals, vacuum lines, water pump, timing belts etc. Then it will go in for paint.

bscpanther

I'm trouble shooting my fuel system now so I'm a little confused. I thought clarks directions were to jumper terminals 30 and 87b?? am I missing something?

potent951turbo

Clarks garage has two ways listed. I forget why he suggests using his preferred way over the other but he explains it on his site.