Old Bentigger

[Old Bentigger]

500SL starting procedure?

As a fairly recent owner of a 1985 500 SL I have been accumulating a (fairly short) list of queries . This one concerns starting the engine when it is warm.By which I mean when it has been running and has stopped for between 30 and 90 minutes.It otherwise behaves impeccably .

The car starts first turn when cold and also when hot but when warm it takes a few cranks, needs the accelerator (or should I be depressing this fully?) , runs lumpily for a few seconds then settles down. Not a real problem in practice but I am puzzled why this different behaviour when warm.

Regards to all :-?

OB

 

[Unleashed]

I'm not entirely sure on your car, but on my 190 before turning the key I push my foot flat to the floor on the accelerator pedal for just a second, then ease off and start. Apparently it's called priming the choke. If I don't do that it starts very lumpy and not well.

 

[stwat]

Im asuming the 500sl is fuel injected, so priming the choke does'nt apply, as it does'nt have one. But im also having the same hot start probs as you OB. It seems to be an over fueling problem. Ive read elsware that it could be the coolent temp censor that is at fault, giveing a false "cold" reading to the comp, which in turn then sparks the "cold start boost valve" into action.

The way to check this is to unclip the connection to the boost valve when hot and see if the problem persists. I havent got round to doing this yet but im going to give it a go this weekend when i service my car.

Stu

 

[pascal]

Please put your query in the title box; not yor name

Pascal

 

[Old Bentigger]

500 SL starting procedure

Yup, I think that is the correct diagnosis , stwat; since I like it to start first time and avoid the ignorant/critical comments from bystanders (with friends like that ....???) I will sort it!

Thanks, Robin aka OB

 

[wingspan]

My 500SL starts like magic but lately having started after a while it starts overrunning at around 1500 rpm. Eventually this settles down but could it be the cold start boost valve resposible for this?

 

[Some guy on the internet]

Oops. Ancient post.