300E misses when hot

I would say in your case, it is most likely the engine temperature sensor that may be the issue as your computer thinks the engine is still cold so provided too much fuel. Another possibility is idle control valve is bad... I would take it out and clean out the inside of it with carb cleaner until it comes out clean. Whack it on table to shake loose anything that might be stuck...

Tiger I just now was able to get time to look into the car. I removed the idle control valve. With it out of the car, I can blow through it. It is partially open without power being applied to the terminals. Is this a problem? With the key in the on position, the valve does indeed fully open. So it is actuating. The question is, should it normally be completely closed with no air flow through it possible?

I don't recall if close or partially open... but clean it out well with carb cleaner... lots of gunks get caught in there.

thanks

I had the same problem.

It's a sensor that goes to the top of engine, at the very rear of the engine. I think it's called a flywheel sensor. They go bad and you would never guess that it's this part that causes the problem.

O.K. the correct name is the Crank position sensor. It's what has gone bad and causes all sorts of problems. The engine dies when it gets hot and will not start till it's cool. Replace this part and the car should run fine.

It turns out we think to be worn valve step seals. The plugs were gunked up. I just replaced them last fall. So I didn't suspect that they were causing my issue. The cold start enrichment would run ok against the fouled plugs , however, the leaner, warm engine mixture had trouble igniting. I may have worn valve guides and I'm not sure what I will do. Thanks for you help folks.