60’s w108 280se ongoing issues any help!!

[Teee]

Hi guys so my w108 has now been to approx 5 garages and still running lumpy, who is the leading classic mb authority in the uk I’ve got to the point I just want to sorted! Also popping out of park (steering column auto).
All service items have been changed, fluids fuel and battery, battery servo, lines, injectors ultra sonic cleaned, timing etc done. Mechanical fuel pump set, ignition timing set, overfuelling had lead to bore wash so oil drained and re-filled. Still running lumpy. Neutral safety switch purchased but incorrect one so existing one was riddled with, held in park for short time now that issue is back again(!)
I’ve spent £000’s on this car and it’s been literally 1.5 years of playing around, just need someone who can diagnose and rectify.

 

[Stratman]

I believe your car has quite an extensive vacuum system, some of which controls engine functions including advance/retard and mixture after warm up. It's almost a given some pipes and connectors will be perished. Get youself a vacuum leak smoke test kit and give it a thorough check.

 

[alabbasi]

I had to read that a couple of times for it to make sense. So let me try to write it back the core issue with questions:
Core issue:
So your engine is running lumpy.

1. Can you describe what you mean by lumpy?
2. Is it missing on a cylinder?
3. When you rev the engine, does it miss more or does it go away?
4. Does happen when cold or when hot?
5. You said that the timing was set, was the injector pump timing set correctly?
6. Was the pump rebuilt?
7. Did anyone smoke test it for vacuum leak?
8. Did you check the co mixture and is it running lean or rich?
9. Has a valve adjustment been done?

There could be a bunch of reasons for rough running. This video explains the mechanical injection pump and how it functions:

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[ray_hennig]

need someone who can diagnose and rectify.

John Haynes, Worthing.

RayH