Dwell setting on 280sl

[davidad]

Wonder if anyone has any suggestions to cure my problem.I have a 280sl with a 130 980 engine,the timing and linkage seem to be ok,and the fuel supply. The coil is a red high power and the ballast resister is 1.8,and i have Bosch WDC9 plugs fitted.
When i set the Dwell at about 38 the points gap is at about 0.2mm,of course if i open the gap to 0.35mm the Dwell is approx 19. To get the car running i have to set the points to the correct gap and it runs ok untill i try hard acceleration and then it missfires and also backfires. would welcome any suggestions

[ja17]

Hello David,

 Your dwell meter msy not nr connected correctly.  Do you have factory electronic ignition on your car? What year is it? Also different types of dwell meters may need different connection points.  With the factory transistorized ignition, a special connection terminal is provided for the dwell meter.   

[davidad]

Thanks for the prompt reply Joe, my car has normal ignition system with a 051 distributer.The engine is a 1968 i think, which i put in about 5 years ago. I have followed the instructions carefully that came with the Dwell meter and am sure it is connected correctly,just cannot understand why i cannot get a correct reading.

[SL113fan]

You will need to connect the dwell meter's "coil contact" wire to one of the leads going into the transistorized switching unit. The correct lead is listed in the manual; I fail to recall which one, but I think it's the one closest to the passenger side.  You'll find that reaching the transistorized unit and the lead may be a bit challenging; just keep trying.

[Benz Dr.]

38 degrees of dwell is normal for the 051 distributor. I think you have some sort of wear problem which is affecting the dwell setting. Worn parts inside of the distributor will allow the point gap to close up during running conditions which will increase dwell angle. If you set the dwell to 38 degrees and it goes down to 19 once the engine starts something is very wrong.