1995 E320 miss on acceleration - PeachParts Mercedes-Benz Forum

PaulSpringmann · #1 02-04-2006, 12:57 PM

Today my E320 wagon developed what I think is a miss when accelerating from a stop. When it happens, the car will just not go; when the accerlator is pressed, the engine seems to stop. When I let up on the accerator, the car idles and creeps forward just fine. I can make the problem temporarily go away by shifting into reverse, and then into drive again. A few miles later the problem re-occurs.

Car has 125k miles. I installed a new OVP 6 months ago from dealer becuase the car would not start. It has the updated part number (the old one did as well). Is it possible that the new OVP is defective? I cannot determine if the wiring harness has been replaced; I've cut it open at the valve cover; it's definitely stiff, but the insulation is not broken. No check engine light or codes. Anyone have any other suggestions? Otherwise, I guess I will see if the dealer will replace the OVP on warranty and then perhaps spring for a harness. Thanks much.

stevebfl · #2 02-04-2006, 01:20 PM

Why would you seek warrantee on a part you have no concept of problems on?

I would presume all aspects of life are a little more expensive due to such logic and the acceptance of some retailers to just go along. If you actually have a problem with the part it should be warranteed. I consider presenting it as failed with no such info, as petty theft.

Besides that an OVP on a 95 E320 can cause a no start, but would be about impossible to cause a misfire. The device is a power supply. The control units that need it work or don't when they don't get power. The early cars didn't need the electronics to run so a bad OVP could cause a running problem, not so with your car.

More likely, are the coils or coil to plug connectors. Those connectors are cheap enough to just replace all three of them (one to each of three coils).

deanyel · #3 02-04-2006, 02:27 PM

There's lots of things it could be. You need to read the fault codes or get them read somewhere. The part number on the wiring harness will tell you if it's original (bad) or a replacement (good). Not a good idea to be cutting it open.

PaulSpringmann · #4 02-04-2006, 10:09 PM

Thanks for the comments, folks; I've already replaced the 3 coil to plug connectors in the past 12 months when one of the coils failed with code 22.

Maybe a miss is the wrong description; is more like the engine completely cuts out when the problem occurs. Acceralator floored and nothing happens, like someone turned off the key. This is why I suspected OVP. I will monitor power after the relay to debug.

I'll check pin 8 once again for codes.

Thanks.

BadBenz94 · #5 02-05-2006, 02:45 AM

Sounds like your mass air meter. Thats what my car was doing, or so I thought. You can remove the wiring to the mass air meter and the car will still run. See if it still does the same thing while its removed(you can drive the car with out it for a long time, just doesnt run as efficiently). I replaced mine twice and then realized it was the engine wiring harness causing the problem. Hope this helps.
Chris

dtf · #6 02-05-2006, 10:41 AM

A side note: check your plugs too. If the electrode is too worn your gap can go from 0.032 to 0.048 (like mine did) and cause this type of problem under load. Make sure they are Bosch F8DC4. What happend to 'total' all those cars?

Thread Tools
Show Printable Version Email this Page
Display Modes
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode