jpitman2

Re the fuses...note that both top and bottom parts that the fuse seats into can be pulled off the board (bottom harder than top, as its thicker and stiffer) and replaced after being thoroughly cleaned. Applying some anti corrosion cleaner is good. Re-tensioning the top connector is also worth doing. Its also instructive to look for heat discolouration on these parts, as well as corrosion. I have converted my high load show stopping bullet fuse holders to blade types with some home made adapters - do a search.
jp 83 Euro S AT 55k

LT Texan

I'd pull the relay and check you are getting 12v to the relay.

Then jumper the relay (is the pump running?) and check again for 12v at the jumper wire.

Then, with the jumper still there, check for 12v at the positive terminal of the fuel pump (with the fuel pump connected obviously).

I figure you'll get 12v at the CE panel and 0v at the fuel pump.

NordicSaab

Alright, new fuel pump and filter in hand. I wanted to explore the electrical to the fuel pump and I am still puzzled...

I used a tester light and the fuel pump relay is good. The wiring to the fuel pump is good. pump the power (Amperage?) is not great enough to make the fuel pump turn on. With a multimeter I am reading 12V at the fuel pump.

Just for confirmation I ran the fuel pump straight to the battery and it turns on no problem.

Ideas?

NordicSaab

So...

It would seem that the problem is upstream of the fuse/relay panel. I can now get no reading what-so-ever at the fuel pump wiring or at the relay junction. I am within minutes from pulling the panel. Anyone have any feedback?

Dennis Wilson

Check the red wires going into the bottom of the fuse panel for 12 volts. If all have 12 volts, remove the panel and look for loose/corroded connections. If less than 12 volts on all/any of the red (30 connection) wires, start at the battery and work forward paying particular attention to the connections at the starter. Also check the connections at the 14 pin connector at the front of the right (drivers side) fender well. Check the connections at the ignition module. While you are checking, jumper the relay connections 15 amd 87 then turn the ignition on (not crank). The pump should run for a few seconds, then stop. If the pump runs, the 87 circuit from the relay to the pump is good.

Dennis

NordicSaab

Dennis,

Thank you for the reply. I think I am moving in the right direction now. I pulled the Relay/fuse panel and there is quite a bit of 30 year old German dust on the contacts. I jumped one of the 3 12v power connections from the panel the the T5 line (line back to the fuel pump from the panel) and the pump engaged. I know now that my issue is limited somewhere in the panel.

The plan at this moment is the clean each of the fuse contacts and re-install with only the #22 fuse, 12v lines, ground, and #T connection in place.

I will update when I have progress... Probably going to be a long night

jpitman2

Dennis, What model years does the pump run for a short period at turn on for ? what controls this timing if the relay is jumpered ? Mine has NEVER done this in any test I have done.
jp 83 Euro S AT 55k

Dennis Wilson

Jay,

Not sure about the ROW CIS cars but all the US CIS Porsches have this to prime the system before start up. It probably has to do with the US specs that require the fuel pump to be off on a non running engine. i.e. the ignition module on US engines have an under and over rev cutoff.

Dennis

AirtekHVAC

Did not see it thrown out there, but what about in-tank strainer and 2nd pump.....my 78 has (2) pumps, and a tank strainer...I had (1) seized pump.....just sayin'

NordicSaab

UPDATE:

Relay/Fuse panel is now re installed.

I polished all of the fuse contacts with a piece of steel wool and blew off the debris with compressed air.

Re-installed only the #22 fuse and the #T plug. With the fuel pump relay jumped the fuel pump will now run off of factory wiring.

The pump will not turn on with the fuel pump relay installed however. I suspect this is because it relies on other parts of the panel to activate?

Either way, I am making progress...

In regards to the 2nd fuel pump located in the fuel tank; I was under the impression by '81 they only had 1 out of tank pump.

NordicSaab

So the new fuel pump and fuel filter are installed.

I ran the battery down over the past week or so playing with the ignition so I could not attempt to start the car due to that issue.

Overnight I charged the battery and re-installed the fuel pump relay.

With a prayer I turned on the ignition and the new fuel pump engaged for a second and then cut off. So, I have my fuel pump back. The relay is working and the car is priming its self prior to crank.

I'm heading to get fresh fuel and I'll be coming back with the intention of starting the car.

The CIS AFM door is still very heavy, but I will work around it by manually actuating it while I crank the car remotely.

Any feedback or advise is appreciated

Dennis Wilson

The resistance on the air sensor plate is due to control pressure in the fuel distributor. Have you gotten a gauge to measure your system and control pressures?

Dennis

NordicSaab

Hey Dennis,

Yes. I just came inside to try to find some information. Maybe a guide or a video? If you are up to it my phone number is (813) 480-2773.

alabbasi

Let's take a step backwards.
Has this car sat for a long time?
Can you spray carb cleaner into the intake and get the car running?
Have you pulled the plugs and seen their condition?
did you disconnect the fuel line to the FD and see if you're getting fuel flow? (1 liter every 30 seconds).

If your FD is acting out or the piston is seized, you may run into problems either getting too much fuel or not enough to your engine.

If you're getting power to the pump and know it to be running, I'd check the above.

If you don't have a fuel gauge, crack the lines slightly open on the fuel distributor and see if fuel is coming out.

NordicSaab

Thank you everyone for the advise...

I have gotten much closer to my end goal, but have yet to get the car started... Please allow me to fill you in on where I am at... I dropped the fuel tank. Purged every line on the car. tested the fuel pump and I am getting Vo3 consistently greater than specification. I also swapped out the Bosch "Blue" coil on the car with a Bosch "Silver" which from what I understand is the correct coil for this car...

I am now to the point where I am adjusting the pressures of the CIS. I have attempted to start the car, but I get nothing more than coughing and maybe 1-2 cylinders hitting at a time. With my gauge between the Fuel Distributor port (on top) and and WUR I get a 70 PSI reading with the valve closed and a 10 PSI reading with it open... From what I have read this indicates a 70 PSI System Pressure and a 10 PSI Control Pressure?

The Air Metering plate is still very heavy, but it is aligned in the middle of the venturi of the potentiometer like the manual says.

Can anyone tell met if these pressure are correct? Control pressure seems low, but I have no idea how to adjust that... Bad WUR? I'm about to give up on CIS and put on the AEM system I have sitting on the shelf...