1994 e220 petrol engine - intermittent missfire - help appreciated

[CJ e220 Wagon]

Hi from the new guy!

I own a lovely 1994 W124 e220 auto petrol estate.

Recently it has developed a miss fire but it is intermittent.

Driving along, suddenly loss of power, along with a sound like a backfire - Ffffft!

Then I stop and rev it in "N" and it will not rev over 4000 rpm - almost like it's limited at that level.

Then I drive off and it wll shortly be OK again.

Weird!

It has 130k miles on the clock, is well looked after and recently serviced including plugs.

Anyone had a similar problem and can offer advice before I have to hand it over to my specialist to charge me a small fortune to diagnose the fault?

I am capable of working on most aspects of the car myself, having spent time as a mechanic many many years ago - it's only a hobby now, but I'll try most things once!

I'm thinking Air meter, coils leads etc....?

Cheers

CJ

 

[fnkhan68]

i would say your heading in the right direction, check the ht leads, dist. cap, etc,etc, sorry i think this model has a coil not a dist cap.

 

[grober]

Twin coils located beneath the inlet manifold each feeding 2 plugs. Known weak spot. Can be the plugs, plug leads or coils OR Wiring harness problem from coils to ECU or even ECU itself. Best get it looked at quick since there is potential for ECU damage in the long term.

 

[Will]

It won't rev past 4000 rpm in park or neutral - this is normal

HTH,

Will

 

[marcintosh]

I had a similar problem. My E200 was misfiring badly when revved past 3.5K in neutral.
I replaced the fuel filter and it has been ok ever since.

 

[CJ e220 Wagon]

I think Will is right - apparently it is normal for it not not rev above 4k in P or N.

Fuel filter was changed at lastservice.

Hate intermittent faults!

 

[CJ e220 Wagon]

Solved.

Plugs changed and also changed the leads, as one was all white and the rest were a bit manky with oil seepage from the rocker cover.

Cleaned up the throttle body while it was exposed.

Car smoother and misfire gone.

Really glad I didn't have to repalce the coils - looked like a really awkward job!

Cheers

CJ

 

[grober]

Result

Glad You Got It Sorted.