I have had a problem with my 1993 190E 2.3 8V for some time. It has had a high idle, so I just parked it and have enjoyed my 1983 300D for a few months now that diesel is cheaper than 91 octane gas. I decided to drive my 190E today to work, it usually starts and drives fine - which it did today. I got home, and pulled the breather off and pulled the IACV off and tested it. It was stuck open, I cleaned and unstuck it, and put it back on. I noticed a tear in the rubber hose going from the valve cover to the "in" side of the IACV, but was careful and got everything put back on. I started it, and voila, no more high idle. The car started, went to 1,000 rpm then dropped down to 750 after a bit. All proud of myself, I started trying to get the stupid hard rubber/plastic holder for the IACV back on the car and ended up taking the IACV back off. While struggling with this part of it, I ended up tearing the torn hose mentioned above off. I patched around with it a little and got everything back on (except the rubber mount/holder for the IACV), was a little concerned so I tried starting it - no dice it just spins, spins, and spins without starting up. I checked to make sure the hose that goes from the IACV to the manifold is still attached under there, and it is. Would a break in the hose going to the IACV cause it not to start? I don't see where it would, as it pulls in filtered air - except I do see a vacuum hose going from the broken hose over to the fuel pressure regulator (everything I found says that is just a vent for the fuel pressure regulator). The car is acting like no spark or no fuel - any ideas?

Update - I went out and fooled with it some more. If I turn the key to run, wait a few seconds, then start it - it will run for just a second then die. I guess I'm going to buy all the air hoses for the idle circuit and see what that does for it.

Final update - got all my hoses in for the idle loop. When I took it apart, it was obvious why it won't run even if one hose BEFORE the valve is leaking - there is a small orifice in the first plastic connector you come to after the one that attaches to the breather. This cuts the air down some before it even gets metered by the IACV. I replaced all the hoses and it starts and idles like a champ. The old hoses were as hard as a rock, and crumbled while taking them off. Back to driving it full time now.