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kcoyle · Joined: 15 Jan 2011 Posts: 712 Location: Long Island, NY

I am trying to troubleshoot my new to me 931 which hasn't been really running right and finally decided to die on the way home yesterday. I managed to restart it and limp home and it died again while trying to back it into the garage. when the car died I heard a buzzing and clicking so I popped the hood and the coil was still firing??? and the CSV was buzzing/humming like it was still on. I was under the impression the CSV cuts off when the ground is lost fron the TTS. Or does it only run when the starter is engaged?Either way it sounds like the CSV shouldnt run for more that few minutes.

Original symptom was stumbling when hot until around 3000rpm and it smoothed out.
Cold start was fine, cold idle was around 1100rpm, warm start was fine, warm idle was bad, hunts between 800 and 1000rpm or so. I just left it for dead for now.

FWIW I have the vacuum elbows and CIS tester on the way from Ideola, plus I picked up new vacuum hoses to install from FLAPS. I also have this site and the Haynes for guidance.(the counter guy even knew bosch CIS, told me to get a long allen key).

I am going to go Kenny Powers on this thing and get it running if its the last thing I do.

Thanks for the ramble.
Kevin
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1982 931- Stock with MBC at 8psi

Relax, all right? My old man is a television repairman, he's got this ultimate set of tools. I can fix it.

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

How did you ascertain that the coil was still firing?

The buzzing you are hearing is probably the frequency valve, located slightly forward of the throttle body.
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

Smoothie · Posted: Tue Mar 15, 2011 1:17 am Post subject:

Ya, CSV should only run while the key is turned to the start position, and for a max of something close to 10 seconds when the engine is cold. (Should run a shorter time with a slightly warmed engine, and not at all when hot.)
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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

Joes924Racer · Posted: Tue Mar 15, 2011 3:32 am Post subject:

Check dizzy cap, /the csv unit runs quitley and floods the engine
unless its at throttle.

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1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

kcoyle · Joined: 15 Jan 2011 Posts: 712 Location: Long Island, NY

Joes924Racer · Posted: Tue Mar 15, 2011 4:33 am Post subject:

and its only run on initial start-up for very few seconds by design.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

Smoothie · Posted: Wed Mar 16, 2011 1:29 am Post subject:

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

dpw928 · Joined: 02 Nov 2002 Posts: 1860 Location: owasso, ok 74055

You will always have 12 volts at the cold start valve during cranking but it only injects fuel if the thermotime switch has completed the ground.

Dennis
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81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black

kcoyle · Joined: 15 Jan 2011 Posts: 712 Location: Long Island, NY

Well, I'm not sure just what the original problem was, but I apparently fixed it. I have taken a bunch of stuff off, cleaned and replaced a bunch of other stuff, and put it all back together. I have a few hundred miles on it and so far, so good.
Basically I replaced all the vacuum hose/elbows, coolant hoses, water pump, timing belt/roller thermostat and temp switch in radiator. I found 2 kinda loose injectors and cleaned all grounds I could find. I took a bunch of white sludge out of the AOS and breather pipes/elbows. Timing looks spot on, valve clearance looks good, compression test was good too.

I also managed to get to Hershey for my first swap meet (family car) and must say I was underwhelmed. The weather WAS terrible, but I did find a few interior bits.

Thanks!
_________________
1982 931- Stock with MBC at 8psi

Relax, all right? My old man is a television repairman, he's got this ultimate set of tools. I can fix it.

pcelenta · Joined: 16 Feb 2007 Posts: 546 Location: long island,ny

kevin,
so where on laaaawng Island are you? I'm over in lynbrook. Close?

Paul

Joes924Racer · Posted: Tue May 03, 2011 4:48 am Post subject:

Thats great to great to hear bro, seems some of the want to accomplish cause its a porsche & I can do, in other words magic or just plain
american fortitude and no-how worked for u . Anywhoooo Gratzi on getting it sorted.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

kcoyle · Joined: 15 Jan 2011 Posts: 712 Location: Long Island, NY

Pcelenta,

I'm in New Hyde Park, about 15 minutes away. Ever make it out to Oak Beach on Sunday mornings?

Joes924Racer,

Thanks. Sometimes it just needs to come apart get cleaned up and go back together. I do some low voltage work and when troubleshooting I'll do just that, take it apart and re-do everything and boom, it works. Customer asks what it was and I tell em, I have no idea!
_________________
1982 931- Stock with MBC at 8psi

Relax, all right? My old man is a television repairman, he's got this ultimate set of tools. I can fix it.

pcelenta · Joined: 16 Feb 2007 Posts: 546 Location: long island,ny

yes. Try to get down to OBI as often as I can...my turbo isn't running yet (soon) but I have an old 356 Envemo Super 90 cabriolet that I take down there. Haven't been down there this year yet (working on my kitchen) but will once we get a full taste of spring and I'm done with the stinking kitchen. We should definately meet up.

regards,
Paul

kcoyle · Joined: 15 Jan 2011 Posts: 712 Location: Long Island, NY

Very cool car. PM me when you might be heading down, I'd love to see it.
_________________
1982 931- Stock with MBC at 8psi

Relax, all right? My old man is a television repairman, he's got this ultimate set of tools. I can fix it.