924Board.org

[ourkid]

We've had it down to minus 4c over the last few weeks and it started instantly and idled better.

Now it's turned mild it struggles and takes quite a few cranks.I've seen this behaviour repeat itself a few times this year.I've already done the hot start switch mod and that does the job but i'm thinking something else is going on?

Ade.
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1983 924 N/A

[Smoothie]

Moisture maybe? Checked inside the distributor cap?
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"..it's made in Germany. You know the Germans always make good stuff."


'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

[Rich H]

Check the Aux air valve is getting power, it'll stay open for longer in cold weather anyway but even longer if its not getting electric.

TTS might also be firing the CSV for longer if its not getting power.
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

[Rasta Monsta]

A car that runs better cold is too rich.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[Adismo]

You can see a lot info in 924.org like this

Why won't my car start when it's warmed up, even though it starts fine when it's cold?

This is a common problem on 924's. The first thing to do is make sure that the car is running and tuned properly. Go through the tune-up section above, to make sure all the basics are covered. Secondly, make sure that it's only a hot-start problem, not when the car is cold. Cold-start problems are different, with different solutions (cold-start FAQ section).

If none of these fix the problem, chances are you do have the "hot-start' problem. This is caused by fuel pressure not being retained at a high-enough pressure after engine shutdown. It is characterized by an engine that will restart within, but not after, about 15 minutes of engine shutdown. To fix this problem, go to the Technical Section under Fuel System.

orrr



2 - Hot Start Problem Fix

A very common problem on 924's is the "hot-start problem." This is where the car will start very nicely when cold, runs properly, and is properly tuned, but will not start without a great deal of cranking when warm, if it has been let sit for more than 15 minutes or so after shutdown. This problem is usually caused by, for one reason or another, not maintaining the high fuel pressure in the engine compartment. Most commonly this is caused by injectors leaking after engine shutdown (they should close shut below a certain minimum pressure) or fuel draining back into the tank - the fuel accumulators and a check valve in the fuel pump (in some cases) should prevent this occurrence. If you are experiencing hot-start problems (as opposed to general starting problems, hot or cold), and the car is properly tuned and in good running order (no vacuum leaks, etc.), then check the injectors and fuel accumulators.

David Russell has provided a very good write-up of how to wire the cold-start valve (usually used on cold starts only) to be actuated manually to help overcome this problem. Hot Start Problem Fix

http://www.924.org/techsection/hot_start_problem_fix.htm

I hope that you find something useful