500SL idle problem after warm-up

A few weeks ago my 500SL W129 stalled a little during acceleration and normal driving condition. Interm. the RPM jumped down to about 1000 RPM and back to normal. Then... it disappeared, but now my idle is higher (only after the engine warms up). Normal it was between 700 and 900 and now it runs interm. between 1500 and 1800 RPM in few minutes cycles. My dealer told me - No error code from the computer, no vacuum leak and the high voltage relay was replaced by the dealer.- Still no success? Should be one of the sensors involved? One more problem since month, here and there all my lights in the instrument cluster light up and the oil-gas-temp- instruments go to zero for a split of second if I use the turn signal (not too important but annoying). Please help. Thank you very much!!!


[Edited by uwe on 12-06-2000 at 11:45 PM]

[mbdoc]

what year car as there are several different fuel systems?

Sorry, forgott to add it, the year is 92,