I'm desperate. Loss of power and rough idle 95 E320!!!
 

I've been dealing with this car for what seems like the entire summer and I have made little to no progress.

Here are the symptoms:

• rough idle
• sounds like a miss
• gas smell
• loss of power
• low idle and near stall condition

I've replaced

• Plugs
• 1 coil that was throwing a code
• IAT sensor
• Coolant temp sensor
• MAF sensor
• Throttle Body
• Fuel Filter
• Fuel Injectors

The wiring harness was replaced prior to me receiving the car.

I get codes that relate to low voltage at ecu, misfire on coil 2 (brand new coil), and then the codes for not having things plugged in. The only code that is really consistent is low voltage code, but the OVP relay is updated to the newer style.

Any suggestions?

have a good look at the socket that contains the female pins that the ovp plugs into and make sure that there is no corrosion and also that the smallest one of those pins is high enough in the plug to make contact with the male pin in the ovp relay as this is terminal 15 and the power supply for that relay.

hello,

I am no expert, but from what I've learned from this forum, M104 missfires can sometimes be caused by incorrect/wrong spark plugs (the M104 prefers Copper Plugs) and also sometimes the spark plug connectors can go bad on the M104 (prt. numbr. 000 159 36 42 (1 per ignition coil, replace all 3))

good luck
tim

A brief update on the progress. I decided to replace the other coils and the car ran perfect. Idled great and accelerated smoothly. I took it on a couple of short trips (less then 5 miles) and all was well. I took a trip about 30 miles and still noticed everything was fine. When I went to start it again the idle had the same poor quality as before and the acceleration was poor.

Only codes I got were: Low voltage at ECU, 8v at ECU, and ICM faulty. I spoke to a MB mechanic and they suggested swapping the OVP just to be safe. The old one had something loose inside and I put in the new one. The car is still just as bad. Now it barely stays running unless it is warmed up or you keep your foot on the gas.

Only thing I can think of being left is ICM, voltage regulator, and ECU.

You sure?

Someone saying they did something does not mean they actually did it.

It was replaced. I checked it.

Idle now fluctuates from 500 to 1500 when idling after warm up.

Was the ETA/EHA replaced with the harness? The internal wires in it have the same insulation in it. That will cause alot of issues. Bad coil packs can be nasty also. Also vacuum leaks can mess with the EZL on the driver side inside fender.

Have you checked the fuel pressure regulator at the front of the fuel rail? Pull the vacuum line and see if there is fuel in the line while running, common failure with a pinhole thorugh the diaphragm.

I am looking at a car with a similar issue... i think its the eta it's a 93 with the 104

Does it have ASR? If not, then you run the throttle plate with a cable.

I had the throttle body professionally rebuilt and yes it has asr. Fpr checked out good.