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Pca944 · Joined: 11 Jul 2005 Posts: 180 Location: SoCal

As you may remember i bought a 100 dollar 1978 924 and a few hundred dollars later and new parts its up and running.

One of the main issues left with the car occurs on cold starts. If I don't play with the gas pedal the car immediately shuts off after startiing it. The battery, most of the fuel system, and the spark plugs are new as well.

Once the car warms up a bit it idles at 900 rpm comfortably and drives with no problems.

Anyone have ideas about what part I need to replace?

Thanks in advance.

Lizard · Posted: Wed Sep 14, 2005 3:14 pm Post subject:

I would start by taking out the AAV (auxilary air valve) and verifying that it is functioning properly,
do a board search as this was recently gone through at length.
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3 928s,

teo · Joined: 07 Sep 2001 Posts: 637 Location: Hungary, Europe

FAQ
Do you have the Haynes or the factory booklets?
It's better if you know why you replace it and what to expect by replacing a part. (not that I do know all the time...)
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Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

How keen is it to start?

If it starts right away and then fails to keep going then it could be the AAV, as Lizard says.

If you have to let it grind away more as the temperature goes down (how cold does it get in Calabasas?) before it starts, try disconnecting the CSV (cold start valve - at the rear of the air plenum) and see if that makes things any better.

Although I know you shouldn't need to, I always start my car with my foot part-way down on the gas, then release the pedal when the engine starts and before the revs rise too much. Try this - if it still stalls, it's definitely the AAV.
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

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Pca944 · Joined: 11 Jul 2005 Posts: 180 Location: SoCal

The car dies immediately after starting it, so I will take a look at the AAV to make sure it is functioning correctly. Thanks.

Lizard · Posted: Thu Sep 15, 2005 3:28 pm Post subject:

try to hold the throttle partially open and see if the car stays running, as all the AAV does is to allow more air into the engine while cold.
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3 928s,

Paul · Posted: Fri Sep 16, 2005 8:29 am Post subject:

Another way to troubleshoot this would be to:

Right before you shut it off for the last time of the day, adjust the idle to about 1300 rpms by backing out the idle speed screw.

Let it sit over night, then start it and see what happens.
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White 87 924S "Ghost"
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Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.