1984 500SL gray market Euro model. After about 1/2 hour to one hour of normal driving, car seems to miss upon moderate acceleration. Could be fuel starvation but feels more like severe missing and gets worse the more it is driven, to the point only level speed can be kept. Changed wires, plugs, coil, rotor and cap. Have not changed control box or capasitor wire. Changing these things helped car run smoother and possibly delays the even from starting until driven for an hour or more but problem still there and consistent. The catilitic converter is not clogged (one was put on when it was imported but it has since been removed). Fuel filter and pump seems ok, have not checked pressure but it has full acceleration before it starts acting up. Doesn't seem to exactly seem to be engine temperature related since I would think it would be up to temperature well before the acting up starts. I am thinks about changing the ignition control box and capisitor wire next. Suggestions please. Thanks, David.
(PS- I was eating up rotors for the last year, tips kept burning off, found out it had resistor plugs and resitor wires installed and I blamed it on that, could be related, have not driven it enough after all the new parts to see it it reaccures)

Could be 02 sensor.

O2 sensor is probably past due for a change, (like most everything else on this car), I grounded the O2 wire and immediately the symptoms SEEMed similar right off the bat. I then left the connection open, ran a little different but not missing. After 1/2 hour of driving the exact same problem started back up. Missing at moderate acceleration at first then after 10 minutes finally progressed to only smooth running on level ground, any acceleration created severe missing, (or possibly fuel starvation but I think is is missing). Any other suggestions?

Good luck,
80 sl acceleration during warm up

Could it be so simple? Tonight, for lack of other options and an hour to kill I started taking out the injectors and blowing some high pressure WD40 through them. 6 of the 8 I got out before my ball end allen wrench broke, most had VERY poor pattern and two I had to blow out with 120 PSI compressed air first. Could it be the problem all along and the enricher thingy was making it run "properly" until well warmed up?, then was gling lean on me during acceleration?? I'll get another shot at it in two days. Opinions please so I don't get down the wrong track again.

That was going to be my suggestion to you! Had the same problem awhile back, and the injectors seemed to clear up my problem. I had a fuel smell though. Yours might not be as bad yet -- mine were actually spraying fuel all over the place, like a lawn sprinkler! One that was fixed, everything ran great. I say that you're hot on the trail!

Now I am positive it was the injectors all along. cleaned (compressed air and solvent, not perfect patterns but lots better) the injectors, everything fine. Put in a WHOLE BUNCH of injector cleaner thinking that would help, WRONG in a matter minutes everysingle injector clogged up with the original problem exactly X100 and I barely made it home. All that injector cleaner must have knocked somthing loose from the filter or ate through some rubber or something. Ordered a new filter and a set of new injectors. thanks everyone. END OF THREAD.