Running rich with CIS...I believe
 

I have been tackling my new 911 and trying to get it up to decent running condition. I currently have a starting problem in that I believe that I am running too rich. My car is hard to start...mainly the car will rev up to 2000 rpms and then die and the gas pedal has no effect. After doing this 5 - 10 times the car will start but run rough and finally level off at a good idle. When I hit the gas after that it takes a second or two for the rpms to increase and it feels like the car is bogged down. So I believe that I am having an issue with fuel mixture. Does anyone have suggestions on how to go about fixing this? I was just going to turn down the mixture and give that a try. Also I am waiting 2 weeks or so for my fuel pressure gauge so I can diagnose further. What I am looking for is suggestions on where to go now or am I stuck waiting for my gauges to be delievered?
Thanks alot.
David

Make sure your cold start valve is being energized during cranking of engine when its cold. Mine, for example, don't have the cold start valve working and it is almost impossible to start but when its warm No problem. Give it a try !!
Truly, Filou.

straight from the book: rough idle when cold.

incorrect cold control pressure
auxilary air valve not opening
leaking CSV
improperly adjusted or binding airflow sensor
unequal injecto flow or spray pattern.

i would wait for the gauges.

cliff

just a stab here, but if your car starts, runs a high rpm then dies, it seems the cold start works fine. Ultimately, I think you aren't running lean, not rich. CIS cars (am I wrong about your 77 911s being CIS?) are pretty notorious for running too lean in colder conditions as the WUR isn't adjusting the control pressure low enough...thus making a lean condition during your cold weather warm-up. You'll know more once you get the guages on it. You also might want to check your mixture setting...

forget the CSV, because it would idle worse and worse as the car warms up.

If you're really bored, remove the warm-up regulator and spray something you think might de-gunk the small mesh screen in the warm-up regulator. (ie. varnish in the screen). Spray it from the inlet from the CIS fuel hose in the circular area. Let me see if I can find a link to a pic...

http://forums.pelicanparts.com/porsche-911-technical-forum/117725-lets-connect-wur-right.html?highlight=WUR

Scroll down and see a pic of the warm-up regulators. That silver dollar sized thing has fuel inlets. One of them (I think) has a mesh screen in it that if varnished can mess with your fuel pressure.