1990 420 SEL Missing at stop light
 

Dear All: I am having an intermittent missing problem at stop lights. Car starts right up, idle speed is good and steady at 700 rpms but at lights when it idles it starts to miss, take off is smooth and engine runs smooth, more noticeable in rainy weather. This happens when the car is warm. I am new to Mercedes and before I go running to a local shop and lose my next pay check can you guys help me out? 169,000 and I don't know when last tune up was done. I did check previous posts...

Many Thanks,
Siduri

Safe to assume that you mean 700 RPMs, rather than 7000 RPMs? 7000 seems extreme for this car.

Check usual suspects, plugs, points, fuel filter, air filter, get a tune up and go from there.

New plug wires fixed identical problem in my 380SE. It owuld do a slight miss or stumble about every 10 seconds while idling.

Thanks to All: Car is in the shop and ignition wires will be checked after the timing chain guides are replaced. Thanks to all for your help....

Siduri