I may have had a relay board failure. My pump quit working. I want to test the board. I can run a positive wire to wire 12 for the fuel pump and it runs. The problem is when I wired the 928 engine I added the cold start and AAR to work when the pump is turned on. So by jumping the pump I still have stuff not working.

I've swapped relays but no good.

What pins can I jump on the relay board to see if it's still functioning? 78 to 30?

I don't have a spare relay board.

Rick,

It looks like 87 to 30 is the switch -according to the VW engine wiring diagram. It's the relay diagonal to the corner and towards the center of the board near the 4 prong connector going to the fuel valve and thermo switch.

That's what I thought. I'll try it later today. Busy day today. Gots ta work!

So are you trying to find primary power to the board? I'm kind of in the middle of the same thing right now(minus the 928 engine). My manual says that the main feed from the ignition switch is terminal 1 on the plug from the main loom... but it's wrong. It's actually terminal 2. I would sooner suspect an open connection to the board(or failed relay) than a failure on the board itself. So find the primary power terminal and jumper that and see if it does whatever it's supposed to do on your car.
BTW, how/why are you using the stock relay board with the shark engine? What are you using for fuel control? It's kind of hard to do a third party diagnosis when we don't know your modifications.
Mark D.

Um, that 's the relay towards the center of the long axis, not the short axis of the board. Number 22 on the VW diagram.

The Porsche factory diagram sucks. I will scan the VW factory diagram that shows just the engine compartment wiring later.

Ken

I have CIS. No management needed except some basic stuff like cold start, WUR, AAV, and a couple of things. Some of which are not working. My engine is pulsing at idle and flooding when it sits over night.

So I have a few issues to unravel. First I need to sort the no power through the relay. Then base line the throttle body, Then start checking the fuel system for leaking injectors and fuel pressure settings.

I'm really not able to devote the time I need to properly test and diogniose this right now. I need 10 hrs in a row without interuption. Working on the Alien is like doing brain surgury through a coke bottle neck.

OK, First the relay board diagram on Pelican has the 85 and 86 pin position swapped at the fuel pump location. This has nothing to do with my issue it just is one of those strange things that make you scratch your head.

So, If I ran a jumper from pin hole 87 to 30 ( which I did ) and the fuel pump runs (which it did ) does that mean I have a dead relay board?

I swapped out 5 known good relays and no joy.

If my helper comes over tomorrow, I'll get him to dig thru the shed and send you a board to swap out. I'd do it, but my hand is in a brace (sprained wrist). If I get it out, I'll send it Monday.

Thanks Bruce, I'm out of touch, What happened to your wrist? Work related?...

Do you need my address? PM? $? pay pal?

yep work related.....either that or to much self abuse

On our way to a call, hit a big dip in the road....stuck my right arm out to ballance myself and came down on the edge of the door frame right on my wrist...

All this time off and I can't do nothing.

Same address as where I sent the hood bumper?

See the tech article for reference: Carb Fuel pump Tech Article

Not necessarily a bad relay board.
It could be you are missing the Power Supply relay or
the power supply relay is bad.
The fuel pump contacts are powered directly from the fuse so jumpering
pins 87 & 30 tests that the relay board connections from the fuse
to the fuel pump socket and continuing to the fuel pump are good.
However, the fuel pump coil gets its power from the Power Supply relay.
If that relay is not installed or bad, then the fuel pump relay will not energize.


If you have a volt meter, Pin 30 (closest to firewall) of the fuel pump relay socket should
be +12v all the time. Pin 85 of the coil (at pin closest to driver side of car)
should go to +12 when ignition is turned on if power supply relay is working
properly working.

Another set of simple tests would be to touch/listen for relay clicks.

When you ground pin 3 of connector T4 (see tech article if in doubt)
see if the fuel pump relay energizes. You should be able to hear it or
feel it "click". If not, and you have a known good fuel pump relay, then
check to make sure the power supply relay is functioning.

When ignition is turned on and Coil goes to +12v, the power supply relay
should activate. Have a partner turn the key on while you feel the power supply
relay. If it doesn't energize the fuel pump relay will not energize.

Given, your pump works when you jumper the fuel pump relay, I'd take
a look at the power supply relay.


--- bill

Does Canada have workers comp? Yes same address. Thanks!

Thanks for the link Bill. I'll double check the power supply relay but I swapped relays and no joy. I'll try the 87 to 30 jumper on it.

Here you go Rick,

The original VW 1.7 engine wiring diagram with what goes where.

Look to the starter for power lines.

Part 1

Ken

Well that was entertaining, the picture was 600x800 and the file was TOO LARGE to attach.

Once again, the infamous VW Engine Wiring Harness Diagram for a 1.7

Ken

And the Rosetta stone to decipher what goes where......