Blast! Another non-start issue

[mikester]

Did a little bit of searching and of course there are all sorts of ideas about what could be wrong but I'm pretty sure it's the fuel pump.

I drove it home yesterday - no problem.

Get in this morning, no fuel pump noise. I had a pretty noisy one so I was actually expecting it to go. I hear a slight ringing or whine but the fuel pump is definetly not pumping and while the engine turns over there is no fire.

Figured I would call up our host today to see if my wife can stop by and pick up a new pump.

Anything else it could be? Pretty sure the fuse is okay, pretty sure the wiring is "okay" but I have to get on it with my tester I suppose.

Well, at least its a long weekend.

[MBEngineering]

HI mikester push the fuel pump relay back in to the holder in the fuse box , if it is not the relay , check the fuse (as the pump has been noisy) for bad connection/burnt. Then report back!

regards mike

[psalt]

Mike,

You are probably hearing the CD unit whine. If you want to test the fuel pump, remove the air filter, turn the key to ON, and lift the air sensor plate momentarily, you should hear it run. Only do this briefly, you are spraying fuel inside. The pump only runs on the START position and when the engine vacuum lifts the sensor plate. I woulds also check for spark with a spare plug and make sure there is fuel in the tank, the 911 gauge has fooled many below 1/4.

Paul

[vash]

paul's move is ALWAYS my first go-to move. if no, go to the red relay, yank it out, and borrow a black one to test if it is the relay. good luck mike.

[mikester]

Welll, I can't pick up a pump today so I'll do some troubleshooting later today when I get home from work. To be honest; the gas tank is pretty darn close to empty (if you're not living on the edge you're taking up too much space) so it could simply be out of gas...

[MBEngineering]

that will not stop the pump working , only make it very noisy until it burns out of it is not pumping fuel??? push the relay back in.

regards mike

[mikester]

Well, I'm starting to think it isn't the fuel pump but there is a noise that was there that is no longer there when I turn the ignition on. It has been replaced with a whine or ring coming from the left of the engine compartment. There appears to be a fuel filter and I think the rear fuel pump there as well as another bosche box that I am unaware of what purpose it is. I'm not sure which the whine is coming from as it is pretty high pitched. I held a tube up to all the parts and my ear but it really didn't sound like it was coming from any of them. It may be lower in the compartment but I was unable to find the cause. When I raise the pressure plate inthe air box I do not hear the pump come on but when I remove the relays I hear a noise and when I plug it back in I hear a noise.

I'm starting to suspect something ignition related.

Oh, and I put 1 gallon of gas in just in case.

[mikester]

I'm 1 and 1 today - couldn't fix the porsche (so far) but I did fix my lawn mower. So at least I did right by one air-cooled engine eh?

[psalt]

Mike,

Again, it sounds like the CD box (ignition) whine, which is normal. It also sounds like you need a CIS manual and you need to read up on the troubleshooting section. The pump does not run unless the engine is cranking or pulling vacuum through the airbox, it is a safety feature. If the pump doesn't run with the key ON while lifting the sensor plate, try jumping terminal 30 and 87a at the red relay socket. Also check the fuse #16, remove it and test it with a meter. If you can't get the pump running, get under the car and test for voltage at the pump connections.

Paul

[mikester]

The whine is the CD box. The problem was the fuel pump, it was the OE fuel pump. Had a new one installed today and all is well. I hope the fuel smell goes away otherwise I'll be back at the shop tomorrow...

Again, thanks for the help and advice.