1995 E320 - Engine missing badly during acceleration - PeachParts Mercedes-Benz Forum

ksing44 · #1 05-27-2009, 05:15 AM

I have a 1995 E320 W124 with 119K miles. It started a few weeks ago, but it only seemed to happen when the car was cold. At first I was thinking maybe it had something to with the choke fuel mixture controls. Yesterday it was pretty bad even after it warmed up. When I push the gas the car just kind of sputters until it finally takes off more or less like normal. To me it feels kind of like the spark plugs may not be firing or like when an engine is being flooded with too much fuel to burn.

This may be wishful thinking, but I'm hoping maybe this is common if it has been a while since the plugs were changed. I have to admit that some of those routine things that were done routinely at the dealer have become only as needed items at my Indy. Something is definitely needed now. It has been a while since I did any engine tuning maintenance things. No warning lights are showing on the dash.

I will be making an appointment ASAP at my Indy, maybe even today, but I was hoping maybe someone here would give me some hope that this is likely only a minor issue and suggest a path forward.

Ferdman · #2 05-27-2009, 06:46 AM

ksing44, my guess would be that the rear-most coil pack is bad ... had a similar experience with our 1995 E320 (which I diagnosed and repaired myself via trial & error by installing a new coil pack in each of the three positions). I'm sure Rex Carle's shop can quickly diagnose and repair the problem.

ksing44 · #3 05-27-2009, 08:37 AM

I've been going to K&S Automotive, even though they are not Mercedes Specialists like Rex. I just really like and trust the guys and liked and trusted their dads before them. I hope they can figure it out too. I will give them your suggestion.

Thanks again,

Ken

J. M. van Swaay · #4 05-27-2009, 08:55 AM

I had a very similar problem with my 94 E320 Wagon. It also turned out to be a bad coil. Mine was a bit difficult to diagnose because no codes were present. I know there was a production run of coils with a rather high failure rate, I'm not 100% sure but I think they are identifiable because they are blue in color. Another common cause for misfire is the coil to plug connector, lots of searchable information on this. As always, posts by Arthur Dalton are always spot on. Fortunately, niether of the above are very expensive, coils are about $75 from our site sponser, plug connectors are less than $5. I would think not more than 2 hours labor would be reasonable for diagnosis and repair.

G-Benz · #5 05-27-2009, 11:02 AM

Coil pack failures are not common.

Most likely, the plug wires are aged. Mine did the same thing, and fresh wires did the trick.

Bad plug wires will cause other issues, such as plug fouling and O2 sensor failure (which occurred as a result of the bad wires).

Arthur Dalton · #6 05-27-2009, 12:02 PM

Want to a waste basket full of them..
VERY common on HFM/SFI Waste Spark/DIS Ignition systems.

But more probable is the 3 plug connector/resistors under each coil.

57farrell · #7 05-30-2009, 06:49 AM

I have 88 w124 coupe with 103 engine. I experienced a similar problem. No acceleration when initially stepping on the accelerator. Motor would sputter and spit the eventually accelerate normally. Sometimes it would sputtrer and spit and I would have to pull over. I read a thread about adjusting the air/fuel mixture on another forum. On my car there is a small cylinder on top of the fuel distributor which on most cars is covered by a small ball. Mine had been removed. You need to remove it. You take a 3mm allen wrench and insert it into the cylinder while the engine is running. If you push the wrench in too far the engine will stall. You need to feel the wrench engage and turn it left to lean right to rich. Probably left to lean to correct your symptoms. The correct method on my car is to use a multimeter an plug the positive into #3 port (positive) and ground the other wire on the meter. You should try to set it at 51%. However you can put the coon tune on it by just experimenting with small turns in either direction. ie= turn to left a little- drive it. etc. etc. My car has Ktronic fuel injection system. I don't know if this applies to your car but I did this prior to buying and replacing parts and it fixed the problem.