dkarten

I posted a while back, my cars performance had deteriorated last July,mechanic said worn motor, motor replaced with 23,000 mile used motor, problem remained, after reading extensively in this forum I was convinced I had a bad Fuel Accumulator, when I removed it I found it very rusty, new one came today, it's not the problem, car barely starts, runs rough, any gas given it drowns, plugs are black, I just got my Bentley & will start researching, any suggestions???????????

LarryF_in_Ca

Read "How to Tune & Modify Bosch Fuel Injection" by Ben Watson. I had a similar problem with my 87' CS Turbo. It turned out to be the Warm-Up Regulator. I replaced the accumulator, but it would not stay running. The tailpipe had black soot pouring out. I replaced the oxygen sensor, since I figured that this soot was clogging the sensor. I then replaced the sensor, but still was getting the same conditions that you describe. I found a killer deal on e-bay for a complete set of CIS fuel pressure gauges, and two books all for $75 bucks.
Make a long story short, Once I connected the gauges it was clear that my warm-up regulator needed to be replaced.
Once I replaced the warm-up regulator, the car starts up like a champ.
You need to read up on the CIS cause properly maintained, it is sort of bullet proof.
Lastly, realizing that my 87' sat for around 3-4 years, so I ran some strong fuel injector cleaner through the system with only half a tank of gas, figuring that this would over concentrate the injector cleaner / fuel mixture. This also helped smooth out the idle among lubing the fuel system.
LarryF_in_Ca

dwengi

+1 - fuel pressure is everything with CIS - you need the special fuel pressure gauge to diagnose trouble. I also recommend Charles Probst "Bosch Fuel Injection & Engine Management" as a reference - in my opinion better than Watson although I use both along with Bentley. And of course SJM has a nice informative website.

I totally agree that CIS once running properly is a very robust and reliable system.

LarryF_in_Ca

Right Dwengi, that was the second book that came with the CIS-fuel gauge and book offer that I stole off of e-ebay.

Dkarten, you'll need to get a fuel gauge connected to see exactly what is going on.

Blauparts has a tester, see below.

I wouldn't replace anymore CIS parts till you get fuel gauge on the system to see exactly what fuel pressures you are currently having.

Good Luck
LarryF_in_Ca<ul><li><a href="http://www.blauparts.com/tools/cis%20tester.htm">http://www.blauparts.com/tools/cis%20tester.htm</a</li></ul>

dkarten

I'll start my search for a gauge &amp; more written info, thanks for the posts guys!!

thanatos

If the the rich running is accompanied with hard start ( after eliminating fuel pump check v, WUR and vacuum leak it is Fuel pressure regulator-behind the distributor box. Any junkyard one , even from 4000 will do...

dkarten

While I'm waiting for Fuel pr. Gauge I will check FPR, I have used one. where is the WUR (warm up regulator?), I have checked Bentley but find no mention. LarryF, what were your symptoms?

S4for73

My freind put my WUR together wrong? and black soot everywhere, even on the grass. Second time he got it right. I took it apart to clean the screen. Now I have a direct fuel line to my dash with a one inch fuel guage permanently installed so I can monitor that sucker. Funny thing is that it doesent read the same every day, but the car runs well.

LarryF_in_Ca

My symptons were, car started, blew out black soot from tailpipe, idled high, then stumbled and died when warm. Pretty much like what you discribed. WUR is located on driver"s side of motor below the spark plugs, you can"t miss it, there are two fuel lines coming from the fuel dizzy down past the spark plugs to the WUR.

LarryF_in_Ca

dkarten

MY car is non turbo 5000S Quattro, as best as I can tell there is no WUR.So far I have installed a used FPR &amp; FD with DPR from a supposedly running car, as well as the new Fuel Accumulator, no change, I removed the ICU (pass. side footwell) &amp; that ran my 1990 100 fine, anyone have any issues with the Altitude Sensor or ECU. I'm waiting for pressure test parts &amp; trying anything else I can