1990 Cabby Karman build, noob here.

[Wolfsig139]

Hello all I just bought a 1990 cabby karman edition. I don't know a lot about VWs other than they are cool little cars. Finally at a point where I can play with a car hobby and I have a few questions.

First off I'm into the car for about 2500. The cabby has been garage kept, paint is about a 8of10 and the interior has new carpet and seat trim. Also she has a new top with glass window and boot.
Mechanically it ran... Black smoked and cut out past 3k very bad. I have replaced the timing belt dist. Cap, button, and plugs. I set the timing to the 6 degree mark with a light at 2200 rpms. (Digifant). Anyway the cabby ran better but continues to black smoke at idle, cutout at idle and at high rpms. So after all this I drive off for a test run and she dies... Tank pump went out. Replaced that and the cutout problems subsided for the most part. Second test drive yielded a further than 10 foot drive thank the good lord. Afterwards I screwed with the timing some and observed the less advanced the less it black smoked. Well back to the 6 degree advance it loads up when warm. Noi have noticed it does zero loading on first crank when the rpms are above 1k. But at idle speed after 30 seconds it will start to load. I know its a wall but want you pros to know my progress thus far, any thoughts? Thanks!

[ToplessBunny85]

My only thought is there's no such thing as a "Karmann Edition." All Cabriolet's were built by Karmann.

Sorry, it's a pet peeve of mine.

[snyder2338]

I am not sure about the black smoke, but the cab has 2 fuel pumps on it. Correct me if I am wrong, but it sounds like you replaced the inner tank pump. There is also an external high pressure pump that is responsible for keeping her running. This pump runs between $200-$250. Generally you will find this some place around the underside of the passenger seat. I just went through this with my cab (mine was running, but not up to high standards). Does the car smell like she is running rich?

[Wolfsig139]

Definately smells rich. I did replace the inner pump. The cabbys stutter has stopped for the most part. Now the issue seems to be rough idle, a studder at 4k under load but past this rpm band is very smooth and strong. Also it seems the wiring to the idle stabilizing thing (250.00) part, the wires have been cut. Idle holds steady at 800ish, is just rough. I'm leaning towards the coolant temp sensor and or o2 sensor?

[stronglikebull]

i would alos double check to make sure there are absolutely no leaks or misrouting or non routing of all of the vacuum hoses.

[Wolfsig139]

Good thought. I have a chiltons book on the car but its vague at best. Any better books out there for the cabbys. The diagrams in mine are horrible.

[phatatude]

Bentley ... Read it, live it, love it...

Cabby's "Lady's love Em... That's why we drive Em..."

[s2kvondeutschland]

HOLY CRAP GUYS. :banghead:

OP, it's your coolant temp sensor, the blue one on the coolant flange. It's best to buy a new one from VW, as there are concerns over the quality of the parts store brands. It should be about $15-20, the $100 part is for the Vanagon, and won't work.

It could be your O2 sensor, but they can't adjust the mixture as far as the blue CTS, Try the CTS first, and the the O2.

[Wolfsig139]

Ok cool I will try the sensor. Any thoughts on the idle stabilizer part. Is it a must, or can the cabbys live without it? Also if its needed the wires appear to be burned in two, and my book shows nothing about its proper wiring.

[CajunSpike]

It could be your O2 sensor, but they can't adjust the mixture as far as the blue CTS, Try the CTS first, and the the O2.

On digi car, black smoke = dead 02 sensor.

I had a cooked 02 sensor, wasn't bad enough to make black smoke though.
Pulled it out, installed a used one I thought was good.
Black smoke
pulled used one out
installed new one
fresh and clean smooth running, nothing else was touched.

[s2kvondeutschland]

My trashed CTS caused black smoke and 17mpg.. Guess you can go either way. CTS is cheaper though. As for the ISV, you can remove it, but you'll have to manipulate the pedal when cold to keep the idle from dropping off. Might I suggest cleaning it out and hooking it back up? Do a Google search for "cleaning ISV. "

[CajunSpike]

My trashed CTS caused black smoke and 17mpg.. Guess you can go either way. CTS is cheaper though.

I agree with trying the cts first by the way.. :-)

[Wolfsig139]

Id love to hook the isv back up but my current book does not show where the wires hook up to. Gonna get a bentley and use it from now on I guess. Chilton not so great for the cabbys.

[Wolfsig139]

Ok finally made it home today and was able to put in some hood time to the cabby. I replaced the coolant temp sensor and the o2 sensor. The cabby runs like a top now, just wanted to say thanks for all the suggestions. Now its time to tag and insure the ol' girl.

[s2kvondeutschland]

Glad you got it running!

[CajunSpike]

Glad you got it running!

Hey we get to share the points on this one for getting it right!