Hi, Today I did a cursory inspection - just a visual - to see if anything obvious popped up to contribute to poor idle quality. Lo and behold - the vacuum line to the Cruise control bellows was disconnected - just hanging there, sucking air. After reconnecting, the idle improved by 50%, but as the car was still warming up, the idle was still at 1000 rpm. Still don't know if the actual bellows unit is leaking - someone has tried to seal it with white silicone. Will do a "hot" check tomorrow. Anyone know how to do an in-situ check of a leaking bellows?

 

sometimes the cruise bellows "accordion" is too deteriorated and silicone does not fix it. Best to replace it.

if the engine is still around 1,000 rpm when cold, it should go down to around 800 after a few minutes.

Check the rubber bellows at the Air Intake, from the front "trumpet" to the air filter, then to the AFM, then from the AFM to the aluminum elbow. A leak there will raise the idling.

 

A couple of more ideas:


1. Does the CC work. If not, it may be that the bellows still leaks. Inconclusive as there are other causes of cc failure. But, at least suggestive.


2. Plug the hose at the bellows. Any effect on idle ?


3. Cold engine idle at 1K not all that high. What is the idle rpm when warmed up?


4. As I get it, this engine is best served with the idles a bit high.


5. My two different cars idle nicely when warm at 500 RPM.


6. If the AC is on, a device on your car might up the idle speed.


Carl


3.