Hello, I did a search first, like a good new forum member, and found lots of info on this topic. The problem is that I found a bunch of conflicting answers and wanted to seek the informed opinions of the group -- Thanks in advance!

The car is a 1990 190E 2.6, with 89K miles. When starting the car from cold, it cranks and starts right away, runs for about 2 seconds and dies. Upon restart, the car cranks for about 5 seconds, starts up and "chugs" or "stumbles" on not all six cylinders for about 10 seconds or so, then smooths out and runs fine from then on. The problem will recur if restarting the car when it's cooled off, but the car starts up perfectly if it's still hot (i.e. if it's sat for less than an hour).

So -- I researched the problem and found a couple prior postings with what sounded like the exact same symptoms. The problem is that the advice received to solve the issue included the following:

1) Cold start valve leaking or malfunctioning (this one makes the most sense to me as it seems like there may be extra fuel being delivered to just a couple cylinders, just for a few seconds)

2) Spark plugs, and/or ignition cap and rotor (I intend to replace these anyway, since I don't know the last time it was done)

3) OVP relay (which seems to get blamed from everything from poor idle and strangely blinking warning lights to bubonic plague and ring around the collar)

Advice?? I don't want to replace the Cold Start Valve on a whim, but I'll do it if it seems to be the consensus advice. What controls the cold start valve -- any sensor or computer things to consider? Are there other things I've overlooked? (I've ordered the 201 CD-ROM but it hasn't come yet.)

Thanks again for the expertise on this forum. I am respectful of the seasoned members here, and appreciate your insights.

Best regards,

Dave Letsche
Saint Paul, Minnesota

Hi Dave,
First, get the fuel pressures checked. Then have the injectors tested. It sounds like the cold start is working fine. That's why the car fires up when you first try to start it. The cold start only operates for a second or so through the thermo-time switch(unless it's really cold out). The further attempt to start is without the cold start valve(since the switch has heated up from the current flowing through it). Either the system rest pressure is dropping or(more likely)one or more injectors are leaking down. One(or both)of these should be it. I wouldn't go after the cold start injector for the reason mentioned above. And failures are really rare.
Without testing first, anything you do is going to be guess.
Regards,
Randy D.

Check/Change the spark plug and wire and also check the cap and rotor like signs of crack wear out.Change the fuel filter this are all DIY job.

Ron

my two cents. . . .
 

I agree with Randy re the cold start, don't think that it's the culprit. Also don't think it's the plugs, wires, or the infamous OVP.

My vote for 'culprit' is ECT sensor. When it changes value, then your symptoms fit what's going on.

When warm, the cars runs very smooth but when cold, the 'computer' is not running rich as it should be. So it stalls and runs roughly until warm.

If you have an ohmmeter and CD for you car, it can be measured very easily.

Is it possible that the ACCUMULATOR(near fuel pump) is involved here?

My 2 Cents
 

I must say that my car did the same as yours is doing for about a year before the symptoms changed. That is, my car started up fine the first time. But it next would stall and hard start after that. Then, this year it started exhibiting much different behaviour. It was hard starting from the get-go. Then, after a few months, the ABS and ASR lights came on and it begain idling roughly. Through this forum, I discovered it was a bad fuse on top of the overvoltage relay. I am no expert in the least, but I can't see totally ruling out the overvoltage relay (or the fuse). Again, my car sounded just like yours a year ago -- it was only hard starting and stalling after it first started normally; no lights were on and there was no rough idling. Though the sypmtoms eventually changed, I guess the problem remained the same because my car runs perfectly now with a new fuse!

Thanks to everyone for the replies - keep 'em coming!

Donna, you mentioned a fuse. Which one?

Thanks

Dave

Jim F

What's an ECT sensor? ECT is an acronym for what please?
Thanks.

My 1991 300E has a ... I think it is a 10 amp red fuse ... situated in a clear plastic holder on top of the overvoltage relay itself. The relay on my car is located behind the battery in the area separated by that fake wall thing. Sorry to be so poor at describing where it is.

Never mind Jim. ECT - Engine Coolant Temp. Sensor
Fell on me like a ton of bricks when I saw a photo of it in another recent post.