924Board.org

[canyonblaster]

After sitting any longer than a couple days. I am able to get it to start after bumping the ignition/starter in small increments and after 10 mins of this or so. When it first does begin to start it only runs for 1-2 seconds then dies. When it finally starts it runs fine as long as I keep revving it until warm.

I do have a refurb cold start valve from Ideola that I have yet to install. I also have a new ignition switch and lock cylinder to install.

Any other ideas.

Thanks
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PCA Licensed Club Racer & Driving Instructor Current P cars: 1981 931
Past P cars, 1985 944, 1987 951, 1990 911 C4, 2002 Boxster S, 2005 996 GT3, 2013 911 C2S
Daily Driver P cars: 2008 Cayenne GTS, 2013 Cayenne GTS

[ideola]

It sounds like the cold start valve, but it would be best to do a CIS test to be sure.

Be aware that problems with cold start could be any one or more of the following:
1: CSV is failing mechanically (i.e. not spraying fuel properly or leaking)
2. CSV is failing electrically (check resistance at connections per Haynes)
3. TTS is failing mechanically (i.e. no longer properly sensing water temp)
4. TTS is failing electrically (check resistance at connections per Haynes)
5. Electrical wiring between TTS and CSV has a fault

The TTS (thermo time switch) is the large sensor that is screwed into the larger port on the rear water flange. Here is a pic of the location from a motor on a stand: the bronze colored dohicky with the brown plug in the lower left of the photo:

Obviously not easy (but also not impossible) to get to with the engine in situ. Make sure the connector is attached before you do anything else. If it is, then you need to systematically test all of the variables listed above, for which Haynes has pretty good instructions, at least good enough to help you isolate the problem. The first thing I would do after checking that the connectors are properly secured is to pull the CSV and see if it sprays any fuel at all during the cold start cycle.
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erstwhile owner of just about every 924 variant ever made

[Rasta Monsta]

You need a CIS pressure tester to evaluate proper function of the warm up regulator, or you are just blindly throwing parts at the car. . .sounds to me like the car is firing on the CSV but cold enrichment is not working well enough to keep it running.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[canyonblaster]

thanks Dan & Rasta!
I will pursue these with the shop, as well as have them install the parts (might as well - I already have them).

I will report back.
_________________
PCA Licensed Club Racer & Driving Instructor Current P cars: 1981 931
Past P cars, 1985 944, 1987 951, 1990 911 C4, 2002 Boxster S, 2005 996 GT3, 2013 911 C2S
Daily Driver P cars: 2008 Cayenne GTS, 2013 Cayenne GTS

[canyonblaster]

The Porsche specialist shop that works on the car has all the right equip and they cant find the problem. Everything checks out and still has cold start issue. Weirdest thing is that the fuel pump doesn't always come on with the key and now the headlight switch turns on the fuel pump...yes, turn key then turn on headlights, then fuel pump turns on....very weird....
_________________
PCA Licensed Club Racer & Driving Instructor Current P cars: 1981 931
Past P cars, 1985 944, 1987 951, 1990 911 C4, 2002 Boxster S, 2005 996 GT3, 2013 911 C2S
Daily Driver P cars: 2008 Cayenne GTS, 2013 Cayenne GTS

[fiat22turbo]

Ground issues. Your experts are idiots for not checking the grounds first. Especially the one between the taillights in the rear and under the dash on the firewall.
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

[canyonblaster]