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Discussion Starter #1
My wife tried to move my 95 E420 she got it about a block away and it died on her. When she tried to start it it would crank then she heard a small bomb . I came home and it back fires as I try to crank it. Lift hood and lot of fuel smell. It has been idling a little rough of late. I haven't really driven it other than very short distances in a few months. Any thoughts.
 

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W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
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Start off by checking the easy stuff first. In this case, I would suggest pulling the distributor caps and rotors and cleaning them up. Do you know the history of the ignition components? Miles since the last major tune-up/maintenance schedule etc etc?

Jayare

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Discussion Starter #3
Thank you. I waited 90 minutes and it was flooded. It started but is running rough and it rumbles in reverse . All tune up parts. Rotors, caps, wires, and plugs all changed in last 6 months. The idle goes very high 2000 then drops to 600 then back up. ?
 

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W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
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Have the upper harness and throttle actuator been replaced?

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SL's & 500E's
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Jayare's questions are very important, all 95's no matter the model have bad insulation in the harness cables. Heat from the engine deteriorates the insulation until bare copper is showing here and there. Many time there are no symptoms until someone disturbs or try to move a cable, then the insulation falls off wires inside the harness, and you can't see that they are shorting out, but things start going south. Upper harness, ETA harness, and lower harness are all affected. I have 3ea 124's with the 119 engine, and were built during the bad harness years like yours. I have replaced/ rebuilt all 3 items mentioned above on all 3 of these cars. Any and all electrical problems were fixed by swapping out the bad(factory) harnesses. The only other thing Jayare also mentioned, the distributors available these days are prone to moisture buildup, and miss firing, driving the need to remove the distributors and clean them out. But your problems sound more like ETA harness shorting out. There are people who can take the ETA's apart and replace the bad harness. Buying a new ETA is $$$$ if it's still available. good luck
 

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Discussion Starter #7
Thank you,I just ordered a new upper harness. Will keep people informed of progress. I love this tank, it's my 4th 124 and my second 95 E420.
 

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W124
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I don't argue with the recommendations to replace the harness because you will need it. It sounds like the problem is in your distributors though. The dust shields are the most common ignition failure point on M119s these days. I'm not sure how an upper harness could cause a backfire.
 

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Discussion Starter #9
I don't argue with the recommendations to replace the harness because you will need it. It sounds like the problem is in your distributors though. The dust shields are the most common ignition failure point on M119s these days. I'm not sure how an upper harness could cause a backfire.
The backfire was solved, Too much fuel(Flooded and blew off a vacuum tube). but it still runs rough. Are you speaking of the black dust shields.
 

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'95 E300 DIESEL, '91 600SEL, '92 600SEL
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It flooded for a reason, and you need to find out why. Unlike dinosaur carb'd vehicles, fuel injected cars do not flood UNLESS their primary sensors are worn or defective, such as the oxygen sensor(s) and mass air flow sensor(s).

Without those 2 critical input devices, the ECU does not know how much fuel to spray

Also, if the harness is eco junk it could be allowing the injectors to spray when they shouldn't causing the air fuel ratio to be knocked out of whack
 

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The backfire was solved, Too much fuel(Flooded and blew off a vacuum tube). but it still runs rough. Are you speaking of the black dust shields.
The dust shields or insulators, are behind the rotor. The cap needs to come off to see them. The original ones, and replacements are an odd orange color.
 

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Discussion Starter #13
The dust shields or insulators, are behind the rotor. The cap needs to come off to see them. The original ones, and replacements are an odd orange color.
I replaced those when I replaced rotors.. I'm thinking that when I recently replaced all the sparkplug wires I "Disturbed old wiring. Hopefully its not to challenging to replace the harness. I love this old beast. It only has 128K on the clock.
 
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