924Board.org

berenlotr · Joined: 23 Oct 2006 Posts: 71 Location: Western MA

alright guys i am getting pretty frustrated, my 79 924 non turbo absolutley doesn't want to start, she is getting a good spray from the injectors, timing is good, but even if the timing was off she should still at least backfire and i am cranking and cranking and not getting anything, please help

Paul · Posted: Fri Dec 22, 2006 11:31 am Post subject:

Are you sure you are getting spark?

The last thing I remember you were having flooding problems, so maybe the plugs are wet or shorted with carbon?
_________________
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.

berenlotr · Joined: 23 Oct 2006 Posts: 71 Location: Western MA

yea all 4 are getting spark and are clean

Lizard · Posted: Fri Dec 22, 2006 12:51 pm Post subject:

is your cam, or spark plugs 180 deg out of sync perhaps
_________________
3 928s,

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

How did you test the spray, while cranking, or manually lifting the air flow sensor plate? If the latter, try taking the intake boot off and lifting the plate a little by hand while an assistant cranks and see if it kicks. . .I am thinking monster vacuum leak or massive fuel misadjustment.
_________________
Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

berenlotr · Joined: 23 Oct 2006 Posts: 71 Location: Western MA

if i crank it with the boot off and the plate lifted a little manualy, how much should i be opening the valves on the throttle body

leadfoot · Posted: Fri Dec 22, 2006 2:27 pm Post subject:

It should start without the need for any throttle...
So make sure your air bypass port on the throttle is clear and that your auxillary air valve is open as well.
Leadfoot
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

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

huckster · Joined: 22 Dec 2006 Posts: 115 Location: Burnaby B.C.

I had the same problem it was the dowel pin on crank pulley. Somone had used a soft rolepin, it sheared and did not turn the cam.

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

Yikes, my valves cringe at the thought of that! Bet it didn't turn over very smooth either, eh?
_________________
Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

huckster · Joined: 22 Dec 2006 Posts: 115 Location: Burnaby B.C.

I turned over great, seamed to have spark, so I learned what every part of the fuelinjection did, and after I tore all my hair out I figered the cam was not turning.

Smoothie · Posted: Fri Dec 22, 2006 3:14 pm Post subject:

Make sure the cold start valve is working.
I've had the problem a couple times lately where the engine had stalled, but the temperature switch was too warm to reactivate the cold start valve on a restart attempt and the engine was still too cool to start without it. I found I could pump the gas pedal while starting to cause the air metering plate to overswing and deliver a richer mix and with that, it would start right up (without any help from the CSV).
Symptom was - not even the slightest hint of it wanting to start. -So check the CSV. Also try the repeated pedal pumping while starting - that might get you going and serve as a quick-easy diagnostic.
_________________
"..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

StienbargerR · Joined: 28 Oct 2005 Posts: 1362 Location: Richmond, IN

What does it sound like when you crank it? Does it sound like its about to start up? Mine sounded like that, and it was just a spark timing issue.

Ryan
_________________
1978 924 NA
-250lb lowering springs, Euro Pistons

berenlotr · Joined: 23 Oct 2006 Posts: 71 Location: Western MA

it doesn't really sound like it is about to start up, i don't think the gas is igniting at all but it does have spark so maybe the air/fuel ratio is way off, not really sure though, going to check the AAV today, clean off all the plugs and try again today

Paul · Posted: Sat Dec 23, 2006 12:29 am Post subject:

All you need for it to fire is the cold start valve, compression, and ignition.

Your timing has to be off, or the plugs are not firing....
_________________
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.