I have checked the posts on here to find out why my car loses power once it starts up. Suggestions were vacuum hoses and idle control unit.I finally got to check out vacuum hoses and idle air control and they seem fine. For some reason when the temp. gets up to 80-90 C the mass air flow I guess you call it a butterfly does not open all the way when the throttle is opened all the way. the engines rpm's still stay up to 7-10k but the mass air sensor doesn't open enough to let more air in. What controls when it opens full. Is there a cold start valve that controls this. My car idles fine. Only seems to lose power once engine gets up to operating temp.
Thanks Vinnie

 

The air flow sensor doesn't seem to hang up when i push it down slowly with my finger with the engine off and the rim is clean. It will open about an inch when the engine reaches operating temp. and I give it some throttle the plate stays where it is and it seems like engine is getting to much gas (poor gas milage too) and not enough air flow.How hard is it for me to replace seals or clean the plunger. If I let up on throttle air flow closes and car idles fine. The Temp. it only seems to happen as the car reaches operating temp. 80-90C this has me a little frustrated.

 

I have a 1991 300e and was losing power at acceleration, there is something called the fuel sender which is and electronic switch in the fuel line delivery system. these things clog and go bad cost @ 200 to fix, but improved power and fuel delivery when replaced