Engine missfiring when cold
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1993 3.2L Mercedes 300E
Engine missfiring when cold
Hi,
My 1993 3.2L Mercedes 300E is misfiring when engine is cold.
After driving for about 8 miles it runs smooth without problems.
I replaced spark plugs and checked the coils. Wiring harness looks ok.
What could be the problem?
Any hints would be appreciated.
Michael.
My 1993 3.2L Mercedes 300E is misfiring when engine is cold.
After driving for about 8 miles it runs smooth without problems.
I replaced spark plugs and checked the coils. Wiring harness looks ok.
What could be the problem?
Any hints would be appreciated.
Michael.
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Joined: Jun 2006
Posts: 4,968
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1990 300ce 24v I6
I had a similar issue. I did plugs, wires, and also replaced all the fuses in the fuse box. Seems to have mitigated the issue to a large extent.
MBWorld Fanatic!
Joined: Jun 2006
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1990 300ce 24v I6
My spark plug wires had some nicks in the insulation, so that may have contributed to it.
I also had the aluminum/ceramic plugs. Apparently, Mercedes has superseded those with copper/ceramic which are not as prone to micro-fracturing.
I did NGK plug wires, and NGK Iridium IX plugs and the copper/ceramic plugs and the bogging down when cold/wet does not happen anymore.
I also had the aluminum/ceramic plugs. Apparently, Mercedes has superseded those with copper/ceramic which are not as prone to micro-fracturing.
I did NGK plug wires, and NGK Iridium IX plugs and the copper/ceramic plugs and the bogging down when cold/wet does not happen anymore.
MBWorld Fanatic!
Joined: Jun 2006
Posts: 4,968
Likes: 3
1990 300ce 24v I6
Thread Starter
Newbie
Joined: Oct 2010
Posts: 3
Likes: 0
1993 3.2L Mercedes 300E
Here's more details on the problem.
When I start the car first time, keep it in parking and don't press anything other then accelerator engine works fine and does NOT misfire. As soon as I press breaks or shift to Rear or Drive engine starts jerking and all the lights in the saloon start blinking like crazy.
I think it’s logical to conclude that spark plugs, spark plug wires and coils should be working fine since engine works fine even when cold until I press brakes or shift gears.
It seems that the problem is somewhere in electronics. May be wiring harness or ECM?
Did anybody experiences similar symptoms?
When I start the car first time, keep it in parking and don't press anything other then accelerator engine works fine and does NOT misfire. As soon as I press breaks or shift to Rear or Drive engine starts jerking and all the lights in the saloon start blinking like crazy.
I think it’s logical to conclude that spark plugs, spark plug wires and coils should be working fine since engine works fine even when cold until I press brakes or shift gears.
It seems that the problem is somewhere in electronics. May be wiring harness or ECM?
Did anybody experiences similar symptoms?
