My friend Hans has a 560 SL (I believe he said it was an 85) with a very strange problem.

It runs at 20 degrees ATDC at idle, and naturally is rather severely defficient in power and the exhaust manifolds are overheating.

Engine control and ignition computers have both been replaced with new ones, fuel distributor is now OK (more on that later), good ignition, etc. O2 sensor is OK, mixture appears to be OK, but with the timing that late it's rather hard to set.

The car itself has a strange history. Seems the PO had this problem, couldn't solve it, and had a carb installed, alonth with a different distributor. Supposedly ran perfectly for two weeks, the problem (lousy preformance) re-appeared. When Hans got it, the injection system had been re-installed, but with a used fuel distributor that was bad.

It will occasionally work fine cold, but once it gets warm, it goes back to very late ignition timing. EHA current will go to 30 mA when cold, but will never go over 2mA on acceleration once warmed up.

Temperature sensors are, I belive, OK.

According to the two most recent owners, the engine/transmission have not been separated, ruling out the possiblity that the flywheel was installed a bolt off (possible, if difficult).

I suspect the crank position sensor myself, as that is the only thing I can think of that would delay the spark that much. Normally, they work or are inert, but I'm wondering if the signal from the pickup is strange (large skew on upswing rather than a nearly vertical volgate rise) resulting in delayed igntion triggering. Rpm signal from the computer appears to be correct.

Any ideas? MB Hotline is as stumped as Hans, no one has ever heard of this particluar condition.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!