My 88 420sel seems to have an intermittent high idle (~2000 rpm) on start up and the engine may be hot or cold. It normally idles around 700-800 rpm in park, but occasionally (1 in every 12 starts or so) it will idle high on start up. I don't like to take it from P to R or D due to the noise/feel as it can't be good for the transmission either.

All I have to do is turn the engine off and restart it and it usually settles down within 1 or 2 tries to a perfect idle. I have seen on a couple of threads that there may be something to the ignition switching to reset the problem, but I would like to get to the root of the problem. The car starts fine every time, operates at normal temp (80 degrees), and runs perfect. The car has about 150k miles on it.

Any help would be greatly appreciated.
Charles
charles_sandra@yahoo.com