Jeff Doble

My car idles really crappy when cold. In fact sometimes the car dies altogether. Mostly it will just drop to about 100rpm and kind of sputter before catching and revving to about 1500rpm by itself before returning to a normal speed. The car works great when warm.

The weird thing is it used to be ok until I got that Motorvac carbon clean done to the car. I figured it must've dislodged a big piece of carbon and lodged it elsewhere. Who knows.

Anyway, I decided to test my cold start valve to see if that could be the problem. I tested it per the procedure in the Bentley and saw a mist of fuel come out while a friend cranked the starter. Is the flow of fuel supposed to be a more defined cone, or is a fine mist ok? It looked to just spray a mist out everywhere in a non-defined pattern.

JD

854KSQ

Sounds good. It only sprays when starting. W/eng running, mixture controlled by cis-e.

854KSQ

Is it an oil flush? If it was a valve decarbonizing you should see an improvement, not the opposite. Hmmm........

Jeff Doble

http://www.motorvac.com

854KSQ

If it was not an oil flush, the engine was running while this process was done. Unless like you said something wierd like a flake of carbon/deposit dislodged and is stuck in an orifice somewhere, you should have seen an improvement. There are some extremely fine tolerances in the cis system. Dude, you're on your own.....Just kidding. You may have to remove lines(pressure/return) and back flush the fuel distrib. (blow in the return). Maybe remove the regulator (gray box on fuel dist) and clean passages w/ carb cleaner. Anyone have other ideas? Now for the technical side... you need to see if the current to the regulator is correct(key on,cold). If it is, you should see a corresponding pressure drop in the lower chamber pressure with pressure guage attatched. Usually .3,.4 bar. This is what richens the mixture. Barring unforseen problems this is the surest way to test for a lean mixture. Hopefully you won't have to resort to parts replacement!