190E Idle & Starting Issues
 

Hey all, having some starting and idle issues with my 1992 190e 2.3. I've poked around here and can't seem to find anything similar to my symptoms.

When it's cold, it starts fine and typically runs fine. But, if it sits less than an hour or so, it's extremely difficult to start. It'll start, but idle at <500 rpm for a few seconds and stall. Sometimes it takes 3 or 4 tries and a lot of creativity with the throttle to keep it running.

Most times -- from either a cold or warm start -- the idle gets pretty low (~500 rpm) when stopped. But I can lightly tap the accelerator a few times and the idle will kick up to about 700-800 rpm and seem to be normal from then on. I also started noticing white smoke from the exhaust when the car is started but not during normal driving (not sure if this is related).

I did a basic tune-up about 2 months ago (plugs, wires, rotor, and cap). The car still accelerates well, runs great at highway speeds, and gets over 25 mpg.

Any ideas of where to start? Some of the threads I've read about idle issues discuss the idle control valve. Could that be a possible culprit?

Check the vacuum hoses connected on both sides of the Idle Control Valve. Make sure they are fully seated at all locations and not cracked.

You might also check the throttle micro-switch to make sure it's closing at idle.

check the spark plug wiring to make sure that the boots are sitting correctly on the spark plugs and have not come loose. there is also a part located behind the battery that is a black square of some sort (not really sure what it is, can someone help?) but when my engine was idling really high, if i disconnected it the idle died down to <500 rpm and sometimes felt as if the car would stall, so make sure that that is plugged in all the way or that you arent in need of a new one.

the smoke is a bit worrying.

my car had some problems like that recently. when cold, it blew alot of white smoke and had a crap idle.

it ended up being a combination of vacuum leaks, bad ovp relay, bad valve seals, and a cracked head.


try checking your compression.