slow idle down when shifting
Thread Starter
Member
Joined: Oct 2008
Posts: 193
Likes: 1
From: Bellingham, Wa
1989 190e
slow idle down when shifting
I've been fighting this problem for months now. I'm starting to lose sleep over it! lol
It's a very strange problem... The car starts great, idles good, all the power is there, the only thing wrong is that when you shift between gears it doesn't idle down (or I should say that it idles down very slowly). You can feel it in the engine braking too - it won't give you full engine braking until you've had your foot off the pedal for 3-4 seconds. It acts like a vacuum leak, but it is only happens while driving
I've replaced injectors, throttle switch, fuel pressure regulator, EHA, cleaned the ICV, replaced ICV hoses (which were cracked), checked for vacuum leaks, adjusted the A/F mixture... Going to replace the engine temp sensor this afternoon. I'm seriously running out of options unless my distributor went bad as a whole. The throttle switch, fuel pressure regulator, and EHA came off of a parts car at work, but what are the chances of both units being bad? And nothing I have done has made any difference so far. I'm thinking it could be a bad O2 sensor, due to the engine running rich for a long period of time ( I leaned it out a bit when adjusting the A/F ratio.
Anyone got an idea? Or maybe a similar experience?
It's a very strange problem... The car starts great, idles good, all the power is there, the only thing wrong is that when you shift between gears it doesn't idle down (or I should say that it idles down very slowly). You can feel it in the engine braking too - it won't give you full engine braking until you've had your foot off the pedal for 3-4 seconds. It acts like a vacuum leak, but it is only happens while driving
I've replaced injectors, throttle switch, fuel pressure regulator, EHA, cleaned the ICV, replaced ICV hoses (which were cracked), checked for vacuum leaks, adjusted the A/F mixture... Going to replace the engine temp sensor this afternoon. I'm seriously running out of options unless my distributor went bad as a whole. The throttle switch, fuel pressure regulator, and EHA came off of a parts car at work, but what are the chances of both units being bad? And nothing I have done has made any difference so far. I'm thinking it could be a bad O2 sensor, due to the engine running rich for a long period of time ( I leaned it out a bit when adjusting the A/F ratio.
Anyone got an idea? Or maybe a similar experience?
Member
Joined: Jan 2010
Posts: 212
Likes: 0
From: OC SoCal
1989 300E
I had a similar experiance with 89 300E that was the throttle plate was sticking "open" a bit. My brother in law was working at a shop at the time and he removed the plate, cleaned it and all was well after that.
You can check by tapping the plate with the air cleaner off and watching to see if it returns right away.
You can check by tapping the plate with the air cleaner off and watching to see if it returns right away.
