Fixed my Stall and No start problem - PeachParts Mercedes-Benz Forum

benfield4 · #1 02-05-2012, 02:55 PM

All

I posted this question 300SE Stall & No start after sitting on the 89 300SE and did some more searching on the forums. Seems a lot of the issues with a good cold start followed by a stall at idle when warm and then a no start until cold again have to do with the distributor cap and rotor. I bit the bullet and ordered the $$$ replacements from my MB dealer. Pulled off my old cap and found that the center rotor button in the cap was broken! It fell out of the cap and came to rest just below where the cap mounts. Saw it sitting there after I noticed it was missing in the cap. The MB branded replacements don't really look all that different from the Bosch replacements I had on there before. They said they were made in Spain just like the Bosch branded parts you get from the aftermarket. Time will tell if they are any more durable. So I replaced the cap and rotor and did a cold start and drive. The car had been sitting unused for a week and it ran fine with no stalling. So check your cap and rotors close if your having this issue. Attached are pics of the cap with the broken rotor button laying in it and the rotor.

sptt · #2 02-05-2012, 11:23 PM

I occasionally get the two crank start when it is relatively warm but always starts up nice and strong when it is colder. Took them out and looked at them one time but could not see any visual deterioration so reinstalled. Not a huge deal right now but wonder if not swapping them out is causing any other unnoticed gremlins or future issues...?

benfield4 · #3 02-06-2012, 12:39 AM

Do you get any missing at idle? I was having some of that recently and now that the new cap and rotor are on it idles low but has not had any missing for the few miles I have put on it. The fuel accumulator is typically the fix for the 2 required cranks on a hot start on a hot day. I did replace mine as well after i verified that the cap and rotor are working. It does start easier now but its only 40 degrees outside during the day. Not the best of tests.

Beware that while removing the cap you can catch the rotor button pretty easy and break it. I think I damaged mine last summer when i put on the new suppressor housing. I have a W126 so if you have a 124 it may have more room. I replaced that cap not long after I got the car and its been almost 2 years.

I think your having a similar issue to mine? check or replace the cap and rotor and pull all the plugs and check the gap. Start with the easy stuff before you get into $$ just to be sure. Good luck and be persistent and methodical. Its the only way with these cars.