Rough idle
Thread Starter
Newbie
Joined: Oct 2002
Posts: 2
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1985 300D
Rough idle
My 1985 123 has 250K miles, just recently developed rough idle. Need to know how to adjust the idle upwards a bit [a temp. fix], and what your theories are as to how to fix permanently, affordably.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 6,211
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From: Laguna Niguel, CA
A rough idle on a 18 year old car can be anything, bad compression, clogged injectors, worn plugs, weak fuel pump, weak coil, bad wires, clogged fuel filter. While it may be easy to replace everything one component at a time, a visit to a skilled mechanic can localize the problem and save you money in the long run. Raising the idle, if possible, may temporarily mask the problem until you get stranded one day.
Thread Starter
Newbie
Joined: Oct 2002
Posts: 2
Likes: 0
1985 300D
My mechanic diagnoses the ruff idle problem as the rotating fuel injector pump -- that of course is the laypersons term. He says I can live with the ruff idle for years if I want to. Now, would increasing the idle RPM just very slightly be a problem?
