Air/Fuel/Idle Mixture Adjustment-924

aaroncuyler · 08-07-2019, 08:26 AM

Hiya,

I've got a 924 1983 that I've managed to get running- new fuel distributor, injectors, fuel pump, fuel filter. I can just about get it running from cold but the longer it's running and gets hot the worse the idle gets and eventually car will just die. It is chugging quite alot and really doesn't idle at all, need to keep the foot on the gas to keep it alive. has a hard time starting again from hot. I have adjusted the idle a little bit before and it wasn't quite right after that. Can anyone advise on what is correct for the idle and also for the air/fuel flow adjustment next to the distributor?

Cheers,

kdjones2000 · kdjones2000's Garage

Sounds like your WUR may be faulty.

I recommend you post on the 924board.org site - they are experts on your car.

GuyS · 08-08-2019, 05:03 AM

Sounds like you got some blockages in your WUR or FD. CIS cars are very sensitive to sitting and don't like old gas. Sometimes, fuel cleaner will help but likely you will be flushing parts and fuel lines to make it right.

aaroncuyler · 08-09-2019, 02:20 AM

Cheers Guys.

I've just replaced the Fuel distributor and have only run the engine briefly since replacing. It does seem as soon as the engine runs for about 5 minutes and get warm it wants to cut out. it's got brand new gas in it and also has had fuel cleaner run through the system. New plugs also. Do you know if WUR has a blue plug? If so, that connection does look dodgy on mine...

944 Ecology · 08-09-2019, 04:55 AM

CIS is a particularly old school, analog fuel injection system.

In a previous life, I owned 1980s Audis and VWs, which used the CIS system. My recollection is that you cannot properly diagnose running problems without the appropriate fuel pressure setup. Check with a local old guy who still has his CIS fuel setup for how to adjust the system.

(IIRC, the electric plug on the WarmUpRegulator was to provide heat to change from cold running to warm running.)

GuyS · 08-09-2019, 05:44 AM

Quote:

Originally Posted by 944 Ecology

CIS is a particularly old school, analog fuel injection system.

In a previous life, I owned 1980s Audis and VWs, which used the CIS system. My recollection is that you cannot properly diagnose running problems without the appropriate fuel pressure setup. Check with a local old guy who still has his CIS fuel setup for how to adjust the system.

(IIRC, the electric plug on the WarmUpRegulator was to provide heat to change from cold running to warm running.)

You are right on the money. Gauges will tell you your warm pressure and cold pressure etc. These systems function by pressures. When debris enters the system it cause the pressures to increase. The higher the pressure, it will lean out. This is likely why the car runs when cold and gets progressively worse.