Andengines,

Thanks for your reply and suggestions.

I had already adjusted the Air Flow Meter per your comments.

I have now around 0.65/0.70 volts.

I double checked the Mercedes specs in the book/CD. They call for .55v to .95v, for engines that are 103.980 .75 volts to 1.05V.

How critical is this? What do you think of changing the AFM anyway, or as it meet specs it should be OK. A lot of the time the engine is sitting at idle and in this position the Air Flow Meter wipers will get its max wear in the same spot? Even though it now meets the specs I still got the idle around 500 rpm in drive. I tried swapping to an old good Idle Control Valve, but the result was the same.

In a separate issue, I had in an effort to get rid of the rough idle, changed the spark plugs gap to .030 from the spec of .035. Today I changed it back to .030. Wow, it made it worse! Is this trying to tell me that I may have a HT voltage problem.

Currently in Park or neutral its almost a perfect idle around 500 rpm. As we know this is not enough for reverse or drive. Once you get going this car drives like it was new!

Sooooo, in frustration today I did a CIS mod. Suggested by another lister under "Ripples in my Coffee". This grounds one of the wires that comes from the Ign switch via the starter lockout. Guess what this does work! For my wife to start using the car its great. However, I'm not happy with the solution.

There has to be something that we can do to solve this problem.

Unless because of the age, and the miles 210k, I have this has an ongoing problem. The biggest overall solution for me was to clean out the combustion chambers and the intake manifold with the BG44 professional cleaning. I have mentioned this earlier in my postings. Not cheap though!

Once you get going with the trouble shooting of the Bosch KE system you realize that the complexity of it all is enormous and there so many factors envolved. I can see why some listers have clocked up thousands of $$$ in repairs by going to the professional shops and they don't have the expertise either.


Incidently I didn't touch the EHA valve, this is brand new and didn't want to mess with it!

Any thoughts

Brian
1989 300ce/210K miles