300sl 1994 misfire when warm

[tommy18]

Hi,
I recently bought a 300s l24v which seemed to run perfectly, but after a long faultless drive home I parked it up for 2 weeks and now this has started happening. Basically it starts, idles and drives fine, but when it starts geating upto temp it misfires badly and will eventually die on me.
It will then refuse to start unless I leave for an hour or so,Then it will start, run fine until it's warm again and then leave me stranded again. If I slowly up the revs whilst it neutral it won't miss, but if I blip the throttle it misses, it really is undri able.
So far I've searched the net and and changed the coolant temp senders as this can supposedly cause this but no change. I then cleaned all the distributer cap and rotor arm as they were in a state but with no improvement.

I really don't know what to try next, has anyone come across anything like this before?
Any help would be greatly appreciated
Thanks

[edpurnell]

Hi,

I would check all air intake pipework for leaks and splits and also any pipes for splits or blockages.

[bolide]

tommy18 said:

I then cleaned all the distributer cap and rotor arm as they were in a state but with no improvement.

Large clue there... I'd replace the cap & rotor arm with MB or Bosch parts and take it from there. After that I'd suggest crank position sensor (I think there's one on that engine) or the hyper-expensive EZL ignition module

Nick Froome

[anonymous-user]

Classic signs of needing a rotor arm and cap replacement.

[tommy18]

Thanks for your help!
I did order a cap and rotor arm last night and fitted them Today. unfortunately I still have a misfire but I'd say there was an improvement. I took it for a drive and it cleared for a while, then on my way home it started again.
It would normally come to a halt and refuse to idle but it was hanging on in there. It's far from fixed thought and now I'm even more confused.
Could it be a coil?
Thanks

[tommy18]

Ignition leads!!! They looked quite new too! Smooth again!!
Cheers