lightangel

MY 1982 928 TURNS OVER AND HAS SPARK.
BUT THE FUEL PUMP DOES NOT ENERGISE
PUMP CHECKS OUT GOOD WITH DIFFERENT 12 VOLT SORCE.
DOES ANY KNOW OF A GOOD FLOW CHART FOR NO START CONDITION.
I HAVE THE PORSCHE CD MANUEL BUT THE FOLW CHART SEEMS TO BE FOR A NEWER STYLE EFI.

SharkSkin

Check the fuse and the relay. If the fuse is good and the horn works, try swapping the fuel & horn relays. If the car now starts but the horn doesn't work, the relay is the problem.

Please note that typing with "caps lock" on is not considered "ideal" in these parts...

Scott M.

Here is another thread of the same problem for you to peruse...

https://rennlist.com/forums/928-forum/227957-no-spark-and-no-fuel-on-my-84-a.html

WICruiser

Relays are known to cause this behaviour. I am not sure about the 82 but my '85 has 3 relays that need to be checked out. The easiest way to confirm is to pull the relay and use jumper wire to bypass it. You should hear the pump run when the pump relay is bypassed. If it still doesn't run bypass the others and see if it starts. This can sort out what relay is causing the problem.

Jack Riffle

I hate to keep repeaqting myself, but here I go again. When you jumper an L-jet fuel injection relay, there are 2 # 87 terminals that must be jumpered to the #30 terminal. Yes, I know, The WSM show only 1 #87 terminal, and they are WRONG! Jumper BOTH #87 terminals to #30 and start her up!

sublimate

Of course that's for the injectors. His problem is with the fuel pump.

Jack Riffle

No fuel pump, no injectors....try it, it costs.....NOTHING!

John Struthers

lightangel,
Seems we are in the same boat.
I haven't jumpered at the relay panel but have swapped the relays out of my 82'
which didn't help. Then installed the relays out of the 'BAD'sHARk into the 82 and they worked fine.
Also made a set of small jumper with alligator clips and jumped from battery to fuel pump and it works fine.
I'm thinking ignition switch, another suggestion was Grounds ... haven't sorted it out yet will check again this evening and let you know. My spare fuel pump turned out to be DEAD anyhow.

WallyP

The green wire (from the ignition box) that triggers the relay may be faulty...

1981 Shark

Anyone got a pic of a "jumper" they've built so I can see how it's done?

sublimate

This thread shows the jumper that was in my car when I first got it:
https://rennlist.com/forums/928-forum/184779-won-t-turn-over-efi-relay-q.html

1981 Shark

Thanks. That's pretty much what I had envisioned, but wanted to make sure. Now for the big question (at least to me). How do I know what prong goes in what relay/prong slot when there are multiple slots for each relay? Bear with me on these questions; I'm still learning (and prefer my barbecues outside ). Thanks. Sorry, not trying to hi-jack thread.
David

UKKid35

Since your car is manual you should already have a jumper you can use occupying the reversing relay socket (the relay is only present on autos), not sure if this applies to MY81 as well as later cars.

sublimate

If you're asking which relay goes in which slot, check the 928 specialists site:
http://www.928gt.com and click on fuse charts to on the left (BTW, I think there are some errors there for MY 82-83, but that's for another post).

But I think you may be asking about the orientation of the relays? If so, you'll notice that the sockets are essentially keyed, as some of the slots go horizontal and some vertical, so the relay can only go in one way.

BTW, in the picture I posted in that othe thread the FI relay is jumpered so the the 15 bus (switched power) is providing power to the injectors. Not sure if that's te best way to do it (as the 15 bus power is probably a little lower voltage and may not be as electrically clean?). As designed, with the relay in place, when the 15 bus is energized then the relay connects the 30 bus (direct from battery) to the injectors. To duplicate that just jumper all 3 across the center horizontally (the 2 shown plus the one to the left, instead of the one below). But I wouldn't leave it like that when the car is parked, as then the injectors will continue to have power even w/ the engine off.

mulik51

Get yorself a voltmeter. Then open up the electric chart(in the WSM. mine were on CD either but had it). Then check for 12V before each switch or relay, or motor. Go backwards. You know that there is no voltage on the pump, so check the relay board, ignition switch, etc.

Klim