'91 190E 2.3 Extremely High Idle, Hot or Cold

[oilslick]

For the past week I have been reading through the "archives" searching for a solution to the extremely high idle in my '91 190E 2.3 and I can't narrow it down.

I am new to the gasoline Mercedes engine. I know the diesels fairly
well.

My car will idle at 2500 rpm's and will drop to 800 rpm's when in
gear. This happens hot or cold. Also, prior to a 60 mile trip last night I
checked the fuse on the OVP and it was blown. I replaced it and it had no
effect on the idle. Of course I used the lights and other accessories
with no problems (other than the ABS light "blipping" on when I turned on
the defrost and the radio cut out but it came back on a few seconds later, this also happens when I turn on the fog lamps) but when I got home the battery was dead as a hammer. The alternator light never illuminated while driving. It does come on as it should when the car is started and goes out normally.

Thanks for your time,
Kevin

[david s poole]

try disconnecting the plug from the idle valve and see if it makes changes to the idle speed.that valve is normally closed and the ecu opens it.if unplugging makes no change then you have a large vacuum leak.

[oilslick]

I appreciate the reply. I tried that earlier and there was no change. There seems to be a few electrical problems and I figure it's all related.

Kevin

[david s poole]

there should be a fuel shut off microswitch mounted on the linkage for throttle see if the plug has disconnected from it.

[oilslick]

I disconnected the ICV plug numerous times and and it never made any change in the idle. I thought I would try again at the suggestion of david s poole and at first nothing happened...so I removed the ICV and inspected it. I found that when the ignition is switched on the ICV is open but after a few seconds it closes. I disconnected it and gave it a few good taps and installed it again. This time the car idled lower...so I tapped it again. It went a little lower...so I tapped it again. It started to go back up...so I disconnected it and now the car idles at 800-1000 in park and 600-800 in gear.

I am going to remove the ICV again and clean it with a slovent an maybe, just maybe it will function normally. Wishful thinking?

Thanks david s poole!!!!!!!!

Kevin