I was wondering if any could tell me what causes the engine to rev up higher when starting, and then drop down to idle speed.

my 1985 190E 2.3 8vlv has a really rough time doing this when I start it and I would like to cure this problem, sometimes on a start, even though it starts up right every time, it will die, on second start it will be just fine, but it never starts up propperly when cold.

This is what I would expect, from 0 rpm to 1500rpm, and then hold it there for a second or two, and drop down to 1000rpm for warm up and then after it warms up to 650rpm all in idle of course. my car does 0 to 650 very slowly as if it's struggling with something, if it does not die here, it will go to a 1000rpm and stay there until it is warm, then back to 650rpm.

Can anyone explain the theory behind this? would love to fix this, maybe something is leaking in my car that I should take a look at, injectors are clean, but it's as if it lost pressur right after you start it up, but I know it does not lose pressur, I tested it.

xp