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Old 03-12-2002, 11:28 PM
knarf knarf is offline
Registered User
Join Date: Jan 2002
Posts: 177
Any Thoughts Appreciated

A few posts back after a valve adjustment I reported that my ignition coil was ticking, '72 350sl, w117 engine.
I took member's reply suggestions , changed coil, coil wire, etc. .
Anyway it turned out that even though the engine timing was 5 degrees atdc @ 750 rpm , per book, the timing was too retarded. The ticking went away after advancing the timing to 15 degrees atdc.
The car starts up fine, but initilaly lidles very high, searching up and down for a constant cold idle between approximatelly 1200 and 1600 rpm for the first 3 - 5 minutes and then settles down gradually to a steady rough 750-800 rpm that can be best felt sitting the car and or listening to the exhaust missfires.
After warm up and shut down the car won't idle warm without feathering the throttle and accelerating the engine(as if burning off excess fuel?) which eventually gets it back to the rough idle mode.
Fuel pressure is good in run mode and holds as required after shutdown.
Temp sensors, cold start valve, trigger points, plugs, points, cap, thermal time switch new or checked out ok.
Sound like an auxilliary air valve malfunction?
I'm also thinking poor injector pray pattern, pressure sensor vacuum hose, ignition wire resistance problem


72 350SL #69
73 450SL Parts Car?
78 450sl Parts Car
79 450SLC - Sold
1985 280sl
87 190E 2.6 - Donated
90 300E-Junked
97 E420
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