Traded an 83 for an 81 Euro S that has cis problems. Previous owner was seeking help here. Spent a half hour looking for obvious problems.

The banjo fitted line from the WUR is unhooked at the fuel distributor due to mismatched fittings.
Both the upper and underneath bolts at the back of the plenum were missing. A huge vacuum leak. After plugging another small leak with one of the rubber hoses connecting the plenum to an intake tube.
Fuel pump only comes on when starter is engaged. It doesn't run in the on position. Pulled the relay and a test light lights in the on position. Is this a bad fuel pump relay?
Thanks,
Fred

 

The fuel pump should run only when the ignition switch is on, and the pump relay is receiving ignition pulses from the ignition system.

 

The WUR is actually the control pressure regulator and it is setting the mixture ALL the time so with it disconnected the chance of the engine running is between slim and none. The control pressure regulator is the "brains" of CIS adjusting mixture for hot or cold ,for altitude, for acceleration under load and for warm up.

 

The fuel pump runs momentarily to provide system pressure then only runs when the engine is running. There is a circuit from the spark controller box to the relay that provides the signal to the fuel pump relay when the engine is running, connection 31b.

To test the fuel pump, remove the relay and run a jumper wire from relay socket 30 [unswitched 12 V] to 87 [switched output of the relay].

 

IF ANY ONE NEEDS WUR OR FUEL DIS REBUILT FOUND GREAT COMPANY THAT DOES GREAT WORK AND VERY REASABLE ( FUEL INJECTION CORPORATION) 2407 RESEACH DRIVE LIVERMORE, CA 94550 PHONE 925-371-6551 FAX 925-454-9715 ANY ? CAN CONTACT ME @ TIM@TIMMYTOOL.US

 

What Jim said re the WUR - and, if the banjo line is off (return to distributor body), and not leaking fuel while cranking, sounds like WUR is blocked, which will give high control pressure, and thus VERY lean mix, unlikely to do more than backfire , which is not recommended for the air plate.
jp 83 Euro S AT 49k, BTDT

 

No, it was leaking from the wur. I wasn't trying to start it knowing the pressures were all out of whack w/o the line being connected. It appears that the previous owner took an extra fuel line from the injectors and was trying to adapt it to the wur. Unfortunately the injector side fitting is too large. I'm just trying to fix the glaring problems before I proceed further.
I'm baffled why the two bolts were missing from the back of the plenum. I'm not sure what they are for but they appear to line up vertically through the plenum. I also don't know if the previous owner took them out for some reason I'm not aware of.

 

There is a very long odd bolt which goes through the plenum and back out on the bottom then pierces the lower air cleaner housing to hold it in place on top of the air flow sensor plate housing it was removed to get the air cleaner housing off of the engine. Part # 928 110 142 00 screw it is no longer available new from Porsche. It used to sell new for about $30.

 

Its alive! I got a WUR fuel line from 928 INTL, and also replaced one fuel line to an injector. I jumped the fuel pump relay and started cracking lines to see how the fuel pressure was. I could see that fuel was flowing through the system but it was bubbly. I wasn't getting the air out of the system. Then I thought maybe its out of gas, I don't have a working gas gauge. Removed the fuel line to the fuel pump and got nothing. Upon further examination I could see the rubber fuel line leaving the tank was badly cracked. Replaced the line, added fuel and jumped the fuel pump again. Now I hear a screeching chorus of noisy injectors firing. Shut the fuel pump down and backed off the A/F mixture. Jumped the fuel pump again and slowly turned up he A/F mixture so the injectors just started to flow after pushing the air flow disc down. I got that great tip here! Got in the car turned the key and she fired up. I have to thank every one who offered me suggestions as well as the countless entries found through a CIS search. This is truly an amazingly useful and powerful website!

 

Had gotten the 81 running a couple of weeks ago, CIS issues, but it wasn't running right. It wouldn't rev over 3K and it wouldn't idle. My biggest problem was I couldn't increase the idle speed enough to get it to stay idling and I need it to idle to adjust the a/f mixture. The first thing that worked was to advance my distributor timing. Now I got an idle and it would also rev nicely. I adjusted the a/f mixture by ear and it now starts and idles well.
But I was puzzled why the distributor was very close to the end of its adjustment slot and why the timing had been so far off. The car had a timing belt change just before I got it. I had replaced a number of timing belts in the past and never had timing issues afterwards. At this point I thought maybe the cam timing wasn't spot on and thats why the distributor was so far off. I brought the cams up t o their marks and the crank is about 3/8 of an inch from TDC!

 

My distributer is near the end of its adjustment slot as well. I think this is inherant t the design. Are you still having the rev'ing issues?

 

Scott, remove the 8mm screw from the distributor body, lift it 1", turn it to jump one teeth on the distributor gear and it will come back to the middle.

 

No, once I advanced the timing it revs easily. I still have to back off the tensioner to reset the cam timing, but even with the timing off a tooth or two it seems very snappy. I'm just curious to see where the distributor ends up once the cam timing is corrected. Right now it is almost as far forward as it can go in the slot.