Hi Everyone, Hope you can help. I have a 1988 190e 2.3 and it's losing power once engine has warmed up to operating temp. It will drive fine until warmed up. Once this happens, it will run and idle extremely rough and the economy needle would be pegged. No acceleration at all. If I turn it off and right back on, it idles smooth again and can rev it up fine as long as it's not in gear. Once in gear it will drive for about 50 to 100ft and then loses power again. While in this state, if I put in neutral or park and try to rev, no power and sometime the Air intake will pop. Normally, I would suspect fuel filter, pump, vacuum, etc. but I think that should happen all the time. Thought about EGR valve but cannot find one on this car. This also happened last year and it fixed itself while I was revving it to troubleshoot. Had air cleaner off and hose disconnected from head cover and saw puff of white smoke? and then it ran fine after that for a year. This time it won't fix itself. Any ideas?

Thanks