W126 idle problems
 

Yes, I've search, and tried everything. No sucess.

(1983 380SEL) will start as normal, but the either stall out or the revving will go up and down (50-2000 rpm) until the car warms up.


Sofar I've:
-Checked and re-soldered the ICU (and cleaned contacts)
-Cleaned the air-slide valve (cleaned with brake cleaner and lubed with atf)
-Replaced thermostat and coolant (had green coolant)
-Changed spark plugs
-Cleaned contacts on the sensors on the thermostat housing


Every contact that was cleaned also got a dose of di-electric greese. cleaner used was caig deoxit. Only thing left if the fuel system (injectors and injector seals) an italian tuneup, maybe?

Sounds like you have a major air leak. The reasoning for that opinion is your statement of severe surging.

Try this: have someone start the car while you gently push down on the airflow meter flap. KEEP YOUR FACE OUT of the way, it can back fire. As you push the flap more fuel will be added. When the amount of fuel is right for the amount of air the engine will run smooth. What is the speed when that happens?

The speed of the engine is determined by the amount of air entering. Fuel only makes it happen. Look for broken brake booster check valve or any other leak. If you can keep it running with the flap trick you shoul be able to hear the leak, especially with a stethescope or a long tube. if using an automotive stethescope remove the end such that one just has a hose with earpieces. Move it around.

Will check.


Another user noted something along the lines of old injectors and worn seals on them, he replaced them and it ran perfect.

A trick I've used is to spray a little carb cleaner at suspected leaks and see if the engine RPM changes. Be careful where you spray it, since its flamable.