Mercedes-Benz Forum banner
1 - 4 of 4 Posts

·
Registered
88 190e, 92 735il, 88 mustang gt 12sec caged
Joined
·
33 Posts
Discussion Starter · #1 · (Edited)
I recently bought a 88 190e 2.3 8V. very clean car in and out. I fixed the vacuum leaks from breather hose to the IAC. 90% of the time the car will not want to idle or just sits and acts like its running on one cylinder,motor jumps around and alot of fuel comming out of the tail pipe. Has new coil,wires,plugs cap & rotor. I tested the coolant temp sensor to the computer and got 884ohms after about 5min of run time. once in the while the idle will go up to 2000-2300 and sit for a while. I pulled the top assembly off the throttle body and checked the bottom rubber and hose to IAC which are ok. I did the "pinch test" to the IAC hoses and idle did change. I put #1 TDC and checked the rotor which was off a tooth and I corrected that and has no change when you move the Distributer from lock to lock which boggles me ... my 1st Mercedes and I build motors and have been a tech for a long time so far and thought that adjusting the distributor would adjust it a little. I didnt put the timing gun on it yet. Is the temp sensor in spec? thought over 500 ohm was in spec which I had 884. Im kinda lost on this car:confused:
 

·
Registered
2008 E350 4M, 2016 Audi Allroad, 2019 Audi Q5
Joined
·
5,540 Posts
If you let the car run for longer it would drop more. Stone cold should be 2-3k ohms, HOT should be 300 ohms'ish. 5 minutes is barely warm, so it sounds to me like it is in spec.

Pull off the idle control valve that those hoses go into and clean it out with carb cleaner. It can sometimes get stuck open/closed with dirt. You'll be surprised how much junk comes out of it...

Timing is computer controlled and not really adjustable. That is not your issue here.

After the ICV cleaning, probe the o2 sensor for operation and confirm the rich running.
 

·
Registered
88 190e, 92 735il, 88 mustang gt 12sec caged
Joined
·
33 Posts
Discussion Starter · #3 · (Edited)
I cleaned out the ICV and the valve itself it moving propery with key on power. I found a post somewhere that told of doing a pinch test on the hoses which when I pinched off the top hose to intake it did stumble a bit and changed when unpinched it. Another issue I found after fixing the vacuum leaks was that the breather hose to the air cleaner has a massive amout of vacuum and unless I put some kind of restriction into that hose it will not idle at all just start and shut off. I used the top of a gear oil bottle and cut the tip off so there was just a little hole so this may be causing some issues? I did call the Benz Barn that specilizes in 190's and he said there is a mesh that should be in the air cleaner for the breather. I was thinking that it was the ICV untill I cleaned it and it is moving properly it seems. there pretty expensive so I didnt just want to throw parts at it and hope it would correct it.
 

·
Registered
88 190e, 92 735il, 88 mustang gt 12sec caged
Joined
·
33 Posts
Discussion Starter · #4 ·
I checked the ohms of the ICV and voltage going into it and its in spec. also rechecked the coolant temp sensor with engine hot voltage in is good and ohm test was in spec.
 
1 - 4 of 4 Posts
Top