idle surge and stalling
 

Hi there, thank you so far to all the suggestions i have had for my problems with '93 sl500.

have checked out absolutely everything now except fopr the ecu.

this is the problem, when motor is cold, runs perfectly, warms up and start to syrge at idle, more like drop away at idle, hwen decelariting it will stall maybe twice a day but worse than that it stalls at pullaway it i put thortle down normally. if i ease it down really slowly it will just not stall.
when the tank is seriously low it runs really rough.

so far i have had oil change, plug change , air and filter change, checked valve timing and was 5 degs out so reset and replaced timing chain tensioner. fault cam up on silver star that cam position sensor was faulty, chaged that, still no change.

when i start the motor it always swings at least 10 rotations before firing unless i start it emediatley after stall, then she fires straight away.

can someone give me some idea where to look further, i have this funny idea that it is something small and simple that we are all mising.

ps also checked fuel pressure, lamda sensors, emmisions plugs, rotor caps leads, crank sensors etc all perfect.

Air flow sensor if it runs fine if you use very gentle throttle but stalls or falls flat with heavy throttle. May have to swap a known good one in to verify, alas, as it won't show up on diagnostics as a bad MAS -- usually a communication buss error.

Crappy diagnostics, if you ask me, but then computer stuff these days is uniformly terrible.

Peter

Similar problems.
 

I cleaned my Throttle Body Actuator and all issues resolved on my 93' 500E w/ 67K miles. You do not have to remove the entire unit for cleaning!