Owner of a 1991 300E and looking for a cliff.
 

Not really but you get the point.

I have looked through previous posts and some of the symptoms match and others don't so here it goes.

My 300E (3.0 liter Straight six) is a 91 with 177,000 miles on it. I started having problems last fall stalling when I stop and sputtering and jerking once I do get going. I brought it in and it was the distributor cap which was replaced and the problem was solved... or so I thought. A few months later I started getting the same problems. it started with the occasional stall when I would come to a stop. But then turned into stalling every time I stop as well as jerking and slowly getting up to speed, as well as when I am going a speed and wanted to speed up it would jump and jerk and I would have to back off on the gas pedal. When I brought the car in before he indicated that the Spark Plug wires needed to be replaced. So I did that a couple weeks ago as well as changing the fuel filter with instant gratification but a day later back to square one. I can drive for about 30-45 minutes fine and then while holding the gas pedal in the same position the power just goes away and i essentially coast to a stall and engine shut off. I start the car and and can drive for only a mile after that with the same thing happening. http://www.peachparts.com/shopforum/...cons/icon8.gif

I have tried the whole fuel additive cures from seafoam to fuel injector cleaner, as well as Isoheet (I live in Minnesota). I got the car two years ago from an unknown owner (through a dealership that go it at an auction) The car had 161,000 miles when I got it I have always used premium gasoline 91 octane being the lowest that I have used. I've always changed oil regularly.

Any thoughts:confused:?

You replaced just the distributor cap, or the cap and rotor? You're getting no fault codes?

It almost certainly HAS to be in your ignition system if you replaced ignition components and that fixes it even temporarily... I think you are on the right path...

Pull the cap off and view the contacts--see what kind of wear they have amassed. Were the plugs changed with the wires?

You should also have the fuel pressure checked for good measure...

-GH

I replaced the actual plugs at the same time as the distributor cap.

I am not very engine savvy. What exactly do you mean by the ignition System.

I have no indicator lights coming on my dash if that's what you mean.

My car does that every once in a while...has the same straight six engine as yours. I get a check engine light every once in a while, I checked the error codes, and it came up as a faulty Air Mass Meter potentiometer. I haven't replaced it, because they car still runs fine, but it will throw a code every once in a while.

Is your engine consuming oil at all? It could be burning oil, and causing the spark plugs to foul, which would explain the strange running conditions...

But honestly, if you've already replaced everything in the ignition system (Spark plugs, wires, cap and rotor) then it could very well be a problem with the Bosch CIS fuel injection system. I would take a it to a competent Mercedes specialist.

Now by putting out "codes" what exactly do you mean? is this something that I can do or would i need a special computer hook up thing? AKA bring it to a MB dealership.

Do a search on how to check codes. No, you don't necessarily need a computer to check them. just count the blinks.

I can not speak for your W124 engine, however, a friend of mine had problems with replacement distributor caps on a 1986 190E 2.3. He finally went to the dealer to get a new cap and it ran fine. Just food for thought.

Thanks Nate but I used a brand new cap when I replaced it. And like I said before It ran Like a champ then started going down hill a couple of months after that.

If you replaced the cap only, and not the rotor, as now twice suggested, the rotor is very likely the problem.

Alright I will look into that. Thank you.

Pull your spark plugs and check them for oil fouling. I remember someone had posted about this same problem a while back and it turned out to be worn valve stem seals. That would not be unlikely on an engine with 177k miles on it.

Hi, I also had this exact same problem for 4 months. I have a 24-Valve 300E 1991. After many trips to the Garage, my mechanic changed the Distributor cap AND the Rotor Button that sits behind it. The rotor showed signs of corrosion and arcing that caused the rough idling and stalling intermittently. No problems now for the last 2000K's. If that doesn't fix it, you would need a very tall cliff!

Dont forget, these cars have oxyegn sensor that gets weak but still dont turn on CE light. My experience is to change these out as poor running engine messes up sensors and cat.

Kind of a bump
 

Well I brought it into a local guy who works on cars in his garage. Doesnt work on MB's much but he said he figured it out but I listened to his message a dozen times and cant make out the name of the part, he didn't sound too sure of the name either he did say however that...

+ It is located by the fuel pump
+ It lets air into the engine.

Any help deciphering? As well as finding the part he said that he has calls out to guys in the surrounding five state area with no luck. Any help would be great I just got done with school for the semester and WANT TO DRIVE!!