Here's the deal:

- '90 240 wagon. Purchased recently. The hose from the intake bellows to the idle control valve had been replaced with a non-standard hose. There was a hose clamp in the middle of the hose. Tighten it, idle goes down; loosen it goes up;

- idle control valve was unplugged. If I plug it in, it won't idle but still runs fine above idle;

- microswitch clicks when throttle is barely moved;

- throttle body is clean;

- the aperture in the idle control valve seems stuck at about 1/8", and cannot be moved manually.

So, two questions:

- is the idle control valve bad? Is it testable?

- the car idles OK (could be better), but above idle, it runs great (best of the 3 240s I've owned). Am I hurting anything? Logic says that the air that is making it idle is always present and never gets cut off. Does that mean the engine is running lean?

OK, that was more than two questions

monty

 

I would say either Idle motor or throttle switch is bad.