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[CorsePerVita]

I've encountered a new issue with our 931. It seems to enjoy stalling when it's extremely cold outside. Symptoms are as follows:

-Idles fine
-Drives fine
-Upon driving for any amount of distance, pushing in the clutch results in the car dying. Instead of returning to idle, it just dies. Sometimes if I'm lucky it'll hunt and then return, most the time it won't.
-Sometimes, if given a small blip on the throttle, it can be manually coerced into not doing this, and then will return to idle.
-After it dies, it is a royal pain in the butt to get started again. I can crank and crank and it may not start. This is pretty embarrassing at a light. Give it 15 seconds and you can coerce it into starting again.

Mind you this is happening at extremely cold temperatures. 5F currently (-15C for you folks on the other side of the pond).

Now... the car was running pig rich. I cleared the plugs, backed the mixture off just a wee bit, and now the plugs after looking at them are about where they should be, not too lean, not too rich. It idles consistently. However, the car still dies when it's extremely cold.

This is an '80 by the way. My 911 did this same thing in the winter time (it was also CIS equipped with an O2 sensor). I never did figure out what it was, it's not a consistent issue unless it's EXTREMELY cold outside. I find it interesting that my normal CIS car does not do this, but my 911 did it a lot when it was cold which leads me to wonder if it's a Lambda thing. Could it be? How do I check?
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- 1977 Porsche 924 2.0 N/A (Trackday Project)
- 1979 Porsche 924 2.0 N/A (The other daily)
- 1980 Porsche 931 (Daily)
- 1987 Lamborghini Jalpa
- 1999 Ducati 900SS

[morghen]

Some old cracked rubber bit acting up?
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Supercharger and EFI kits
https://www.the924.com

[CorsePerVita]

[CorsePerVita]

In the second pic you can see the main line is replaced. However, 2 of the others are still old. I opted not to replaced them just yet as I didn't see any obvious cracking when I took them off. Doesn't mean there couldn't be, however, I still don't know how that would affect an issue like this specifically when it's about 5F and no other time when the car is running.
_________________
- 1977 Porsche 924 2.0 N/A (Trackday Project)
- 1979 Porsche 924 2.0 N/A (The other daily)
- 1980 Porsche 931 (Daily)
- 1987 Lamborghini Jalpa
- 1999 Ducati 900SS

[Paul]

Air flow meter or fuel distributor piston sticking at idle? (slams shut when you lift off the throttle then sticks closed instead of opening slightly to provide some fuel.)

But as always check your system and control pressures.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[CorsePerVita]

Hi Paul,

I did the palm trick with the CIS mix screw (touch slightly with a small allen wrench, see if richening makes it worse or better) and the idle became even worse. I backed it off just a hair. The car idles awesome and runs 10x better now.

I replaced and gapped new plugs. The battery died the other day in -22F weather. Replaced the battery. The car has given me ZERO trouble since. Runs better than it ever has. So THIS is how a turbo should feel
_________________
- 1977 Porsche 924 2.0 N/A (Trackday Project)
- 1979 Porsche 924 2.0 N/A (The other daily)
- 1980 Porsche 931 (Daily)
- 1987 Lamborghini Jalpa
- 1999 Ducati 900SS