300E stalling right after starting, then will start right up again
 

My father's '87 300E will about 9 out 10 times die as soon as started. It stalls almost as soon as it is started. After it stalls it will start right up like nothing happened. If you give it gas when first starting it, it will start fine (minus the higher revs). I have already cleaned the idle control valve although it did not look dirty at all. Are you suppose to be able to tell by just looking in the inside of it? It use to surge at lights but I believe that was fixed when I did the idle control valve. I have done searches on the sbject and they normally point to an OVR valve when there is stalling involved. But, their stalling is normally when driving though. Pleae help as I would appreciate any help I could get on this matter. It is very annoying to either hold the gas or restart it everytime.
Thanks
David

P.S.
This happens when the temp or engine is either cold or hot.

anyone?

I'm having the same problem. I hope someone will answer.

My $0.02
 

My kid bro's 190e had a similar issue.

Would only start on 2nd try.Will start only on 1st try with help from accelerator.Warm or cold.

Also, in his case, we could smell fuel near the rear of the car all the time.

We swapped the fuel pump.Now, fuel smell is gone.Car starts fine on 1st try without accelerator when cold.

However, it still has a hot start problem.

We recently changed the fuel accumulator but that did not solve the hot start issue.

Interesting to see if anyone else has the same issues.

Azhari
Babybenz 1991 190e 1.8

do a search on fuel pump relay. it addressses to
a lot of fuel related issues.

Mine only tends to start when given a little throttle too, but I live with it, it's a 17 year old car after all.

IMO I don't think the fuel pump relay would lead to these problems, it usually causes the car to cut out intermittently, not cold/hot start problems.

You can't expect to get alot of responses within, say 1/2 hour of the original post.
It sounds more like the overvoltage protection relay, possibly just the fuse on top of the relay, I'd definitely start there first, especially if it's more likely to do this when the engine is cold.
Another possibility is a bad engine temp sensor.
The OVP is located behind the black plastic panel behind the battery, it has a flip open lid with a red 10 amp fuse under the lid, check that fuse. Is the ABS light also on? If so, I'd replace the OVP even if the fuse is OK.
Do a search on OVP or "overvoltage", lots of clues there.

Gilly

ps Most fuel pump relay problems I've seen were tow-ins, that is, no start at all, dead relay.

I have the same problem. I replaced the OVP relay and it helped with the cold and warm idle in general, but didn't resolve this particular problem. I did notice that if I turn the ignition on and wait a couple seconds before I turn the engine over (as if I'm letting the glowplugs warm on my diesel), it starts and runs just fine. This leads me to think its an issue with the fuel pressure regulator or fuel filter. Either way, its such a minor issue that I just live with it.

GregS
'84 300D
'90 300CE

I have this problem with my 300E when the weather warms up. It started last year. Once it starts, it runs perfectly. It appears that the problem is that it's not getting enough fuel (pressure?).

It's irritating.

I'm afraid if I ask the dealer about it they'll start throwing parts at the problem.

This problem is so prevalent that you would think there would be a clear solution.

This happens when the engine is cold or even if I just turned it off sometimes. If I turn the engine off, then restart it 5 minutes later it will stall like normal. It does not matter on the outside or engine temp.
David

If you'll search here a little, you'll find much information on this problem. It seems to be either a slight loss of fuel pressure after the engine is turned off. This decreased fuel pressure is most important on a hot engine when the cold start valve isn't a factor. The check-valves on fuel pumps, fuel pressure accumulator, fuel pressure regulator and fuel distributor and injectors are all known culprits. Either start swapping parts or do a fuel pressure test. Another thing that sometimes works is an adjustment of the plate in the throttle body (but this one is tricky). I'm no expert here, that's why I suggest searching the board. I did go through this with my old 87 300e. I stopped short of the fuel distributor and pressure regulator due to the costs. The other parts all offered incremental improvements in the problem , but it never went entirely away.

Good luck

A lot of people are relating a lot of problems to the infamous OVP. From what I read on this forum, my guess is that 85%+ of the OVP replaced do not solve the problem raised. Throwing parts at an undiagnosed problem is frustrating and expensive.
In this case, I'd start with the fuel pressure regulator and fuel filter.
JackD

The EPA emission certification test begins with a "cold start" at about 70 F. The amount of cranking and after start enrichment is minimum at this temperature, and it's been my experience that my car has poorer cold start behavior in the summer by sometimes stalling after firing up. Cold start behavior in cool weather is much better.

To work around this issue I just give it a little throttle as it fires and hold about 1200-1500 revs for two to three seconds. After that the idle stabilize at about 1000, and you're ready to drive off. This "problem" is not just limited to Mercs. A lot of cars exhibit similar behavior, and it probably results from the OEMs setting the cranking and after start enrichment to minimum levels. About 80 percent of the total EPA certification cycle emissions occur in the first two minutes of operation. This on a test that takes a total of about 45 minutes including a hot soak for about ten minutes, so the cold start enrichment in the vicinity of 70F is calibrated on the ragged edge of leaness.

Sometimes it's better for us to adapt to the car than trying the get the car to adapt to our preferences.

Duke

P.S. The following complaint is written on a 5/31/88 RO when my car was about four months old:

"Cust complains when starting at times it starts and dies"

They could note duplicate the problem, but wrote me the following NOTE: "All systems with EZL ignition system 5 seconds cranking time to start normal."

Almost same behavior
 

My does the same thing, but only when warm. I crank, and it dies right away. It always start at the second try.

When cold, first thing in the morning (after sitting overnight) it fires up inmediately.

I just live with it.

So what should I do then? Everyone keeps saying that they are having the same problem but it seems that no one has a really good answer, lol.
David