My '79 280E is getting horrible fuel economy. It runs fine stone cold, gets rough a minute later but idles ok again when fully hot. Except after a very long run in hot weather. Then it gets a misfire when returning to idle and on first take off. If you put your foot down it and give it a rev, it clears up, which seems like the plugs may be fouling???
I took the warm up compensator off this afternoon for a look. Pulled it all apart and cleaned it out. There was a great lump of something behind the thin metal diaphragm thingy. When I applied 12V and it warmed up ok.
I assume it should get 12V, but under what conditions. I turned the ignition on and got nothing across the terminals of the connector. Nothing either when using a separate earth and probing each terminal individually. Yes, it was cold.
I've yet to try it again as I'd like to know if I should be chasing an electrical problem here first.
Many thanks in advance for any advice.