924Board.org

[p0rsche]

Car ran well untill a few months ago. Began to start/stall a few times before eventually starting and running well. Found and repaired a minor fuel leak in the flexible fuel return line near the tank. Had to drain the tank to fix. Cannot get the car to run since the repair. Starts and stalls after 2 seconds - over and over again.
It will run (badly) if i continuously spray starting fluid directly into the intake. Any advice would be appreciated.
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Jeff

1980 924 Turbo

[ideola]

Sounds like a serious fuel delivery problem of some sort. You need to start with a proper CIS test. If that checks out (warm + cold x system + control pressures, + leakdown), then you need to check fuel delivery (volume, flow, pattern, etc. at the injectors).

But before you do any of that, make sure the overboost cutoff switch didn't get inadvertently disconnected. To eliminate it as a culprit, I strongly recommend grounding that lead out until you complete the other diagnostics.

Recommended reading:
http://www.924board.org/viewtopic.php?t=35734
http://www.924board.org/viewtopic.php?t=28790
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erstwhile owner of just about every 924 variant ever made

[p0rsche]

Thanks very much! I'm sure it will take me a while to get through all this. I don't have much free time.

I don't have a tester and may not be able to afford one. How much are yours? Are any other special tools needed for other tests? I have a good collection of standard tools.

I'm trying to decide if I should cut my losses. The car also needs the shifter linkage bushings replaced, a heater blower motor, a rear bumper and some exhaust work.

Thanks again.
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Jeff

1980 924 Turbo

[p0rsche]

So I bypassed the overboost switch and the car tried a little harder to run. It ran a bit longer (~3 sec). So I'm guessing the switch is at least a contributing factor to the problem. I'd like to check/replace all the vacuum lines next.

Where I can find a comprehensive list (with pictures) of all lines that should be checked/replaced?

Also, it smells like it might be running rich. Any thoughts?
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Jeff

1980 924 Turbo

[ideola]

[Rasta Monsta]

[p0rsche]

Update:

Fuel pumps are working and all small vacuum lines have been replaced with silicone. Other lines and elbows have not yet been replaced.

I can get the car to idle smoothly if I hold the metering plate down slightly. Otherwise it stalls quickly.

If I throttle-up, it will stall. If I throttle-up while pushing down on the metering plate I can get it to rev nicely.

I will continue to replace vacuum lines and elbows. Is there anything else I should be focused on?

Thanks!
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Jeff

1980 924 Turbo

[Grenadiers]

Have you tried turning out the idle air screw on the throttle body? Sounds like you are running rich, surprised it starts if so.
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'83 944 Track car.
'88 924S Track car.
'89 944 Turbo
2004 Winnebago Vectra monster RV
2012 Jeep Wrangler
2014 Kia Soul
2001 Ford F350 powerstroke

[ideola]

Have you purchased a CIS Tester and conducted the tests yet??????
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erstwhile owner of just about every 924 variant ever made

[ptheskil]

You are running lean. Pushing down the metering plate on the 931 increases the fuel flow rate. There are many problems which can cause lean running but only two causes : too much air or too little fuel. You are working on the too much air problem by chasing down vacuum leaks (any leak after the metering plate, not just past the throttle plate). To rule out fuel problems you MUST do the fuel pressure and flow rate tests - it is the only way to reliably diagnose CIS fuel delivery problems. Once you know the results of those tests you can systematically put things right. I suspect that your initial running of a few seconds is due to the additional fuel supplied by the cold start injector. You could spend a lot of money and time replacing things you don't need to if you take a "short cut" by not doing the CIS tests.
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1981 931 series2 Euro spec