[Rick Lee]

Guys, this is my old SC. I miss her and want her healthy for when Fax sells her back to me.

Fax, the WUR is almost new. I replaced it shortly before you bought it. I don't believe the injectors have ever been replaced, though I did mark date and mileage on the fuel filter last time I changed it. FWIW, my lean mixture problem in my 993 was remedied once I got my injectors ultrasonically cleaned. Ran me $164 and was worth every penny of it. I never drained the gas tank, so it may indeed have some gunk down there.

[Cliff Claven]

Originally Posted by type954

this thread will be very important to me also to help learn about CIS. my fault is that the engine will high idle ~1400-1600 rpm when hot. i was told to suspect the warm up regulator. any comments/questions?

What kirk says. Could be one or more of several different potential faults. You need to figure out, is it a fuel mix problem or false air problem. This means checking both your mixture (emissions levels) and fuel line pressures under different conditions. The so-called warm-up regulator, more accurately called a control pressure regulator, works (through fuel pressure control) to enrich the mixture on cold start (and on hard acceleration). Auxiliary air valve works to add extra air-flow past the throttle plate on cold start, which also causes higher idle if not shut down on warm-up. AAV can be tested with the freezer test, though it could work fine in the test but still not function properly on the car due to an electrical fault in the circuit that controls it. There are also vacuum lines contolling fuel/air switchs that can influence idle. You just need to start testing.

As for the original question, could very well be clogging in the fuel distributor, which is a major pain in the ass and/or high dollar repair (though possibly a good excuse for investing in carbs).

[phaques]

I bought the Bosch Fuel Injection book by Pobst, which seems to be great. Dropped the fuel tank, rinsed and dried it thoroughly, installed a new fuel pump, pumped gas from the tank through the new pump up to the inlet side of the fuel filter to flush that line, installed a new fuel filter, and started the car to see what I got (hoping I got really lucky..). Car started fine cold, ran fine for 30-45 seconds, then started wah-wah-wahing, backfired, said f*ck you, and died. I'm assuming the pump is fine (since it is new), but I guess I should test flow rate through the filter and in the return line between the pressure regulator and the gas tank. Also, if I had a bench fuel injector tester (hint, hint....RickV?) I could test the injectors.

[Rick Lee]

Fax, I put a new fuel pump in there in Dec. 2004 and I think I gave you the receipt for it. This one is a real head scratcher.

[markwemple]

How was the tank filter. "We" always remember to change the one in the engine bay but I believe yours came with one that was a screen in the tank as well.

[phaques]

Rick,
Thanks - I got a good deal on a basically new pump, so I bought it. But, I never throw any parts out so I'll label your old pump w/date and mileage and stow it somewhere. My diagnostic skills in this area are weak, and I'm baffled. There was quite a bit of visible junk in the tank when I took it out and held my match down in there to look around, but I rinsed it pretty well and blew it dry....my working theory is that I've got a clogged injector or two, but I need to find a way to test them. I may try the quick check method first (run the pump with the car off, stick the injector in a jar while still attached to the distributor).

[phaques]

Tank filter didn't look too bad. No holes, and a rinsed it and blew it dry, and tried to blow any debris out of it.

[phaques]

Okay, in my searching on the topic, I have found a couple of very good links on this topic. One, http://www.classicsaab.net/library.html contains a link for the COMPLETE Bosche K-Jetronic with Lambda technical manual (first link under the Engine section), but BEWARE, it is 178 Megs and a total hog to download. On the same page is an excellent link for CIS troubleshooting, the second link under the engine section, and a much more manageable download.

[86911TLCAB]

while no expert on this...when i tested my injectors, i pulled all six and stuck them each in a bottle so as to prevent getting unburnt fuel into the engine. Can lead to other undesireable issues...tito

[Cliff Claven]

phaques, what noah said earlier, you need to check the flow to the injectors cuz its very possibly the fuel distributor. when that kind of crud from the tank gets past the fuel filter, it can end up clogging the furel distributor. unfortunately a rebuilt fuel distributor costs big $$$$$. and it's hard to rebuild yourself. could be a good excuse for switching to carbs.