94 E320 Stalling Problems
 

OK here it goes, My car has a problem. It will periodically shut down on me or run very rough, it seems to occur more often when its wet outside. It has thrown engine codes and it keeps saying its the mass air meter, however i have had it rebuilt and still had the problem(sometimes it runs sometimes it doesnt, and when it doesnt i just unplug the mass air meter and let it run like crap) then installed a brand new unit form Bosch,same problems. Some has ssaid the Overvoltage protection relay, and I havent replaced that yet(im afraid of just throwing parts at it now). What r some ideas out there? One last note my camshafts (104 engine) once in a while will not advance at 3500rpm, sometimes its latter, and if that occurs it will advance than not, then advance again...Im open to ideas and I would like some sanity back in my life, Thanks to all!!!!
Best Regards

Chris Pachorek

It sounds to me like a bad engine wiring harness.

Do a search on this site for "engine wiring harness", and you'll be up all night reading posts.

They were bad on all E320's from '93-'95, and it looks like yours has just started to fail.

Chris, I would check the part number of the overvoltage relay first.
MB number 000-540-52-45 are known bad, replacement number is 000-540-67-45.
Located behind the battery, remove plastic cover & there it is.

Bad OVP relay will bring on ABS warning light when engine running.

ovp, wiring harness, oil leaking into plug holes in the head, shorting a coil or, bad coil. (pull it, remove the resistor tip and look for oil in the hole, if it's leaking, it'll be bad now or soon, they overheat and break) dynamic chamber flap (resonance flap) on the manifolds will also fall apart sending rubber and plastic into it, holding valves open and causing it to skip and/or backfire. (pull it and see if the flap is coming apart)



Joe

did this happen right after a fill uP, if so take a fuel sample first and look for water, or dump a can of dry gas in it for the hell of it

Thanks for the tips, Im going to check the harness and OVP this weekend and I will let you guys know, I printed off all of the comsumer complaints at the NHTS about the wiring harness and all of the info in this forum and brought it my relatively local Mercedes shop and he offered to get me a new harness for free if i installed since Im second owner and I now have 182k miles on it.
So thanks for the help and I will let you know of my solution and findings!!!:)
Best regards

Chris Pachorek

If you end up changing the harness yourself, I'd be really curious to hear how it goes.

I too haved a 94 in need of a new harness. The dealer hasn't been as generous around here, but I have thought about swapping the harness myself.

Let me know how it goes.

Thanks.

[quote=joe p;293163]ovp, wiring harness, oil leaking into plug holes in the head, shorting a coil or, bad coil. (pull it, remove the resistor tip and look for oil in the hole, if it's leaking, it'll be bad now or soon, they overheat and break) dynamic chamber flap (resonance flap) on the manifolds will also fall apart sending rubber and plastic into it, holding valves open and causing it to skip and/or backfire. (pull it and see if the flap is coming apart)



nice one joe! good post!

i was just googling this resonance flap! since i got a problem with my c280 m104 engine 1996 revised engine harness version.

this is my exact problem! there is an lpg conversion on the car and it backfired abliterating the plastic flap! i took it out and there is no flap! it was gone. my guess is some of it has gone into the engine / and some of it is blocking the air flow causing the mixture to be too rich.

as a result the car now back fires a little running on petrol. the revs just drop sudenly, but only a little! i have been having huge backfires on lpg. now just running on petrol. changed some coils over from my e36 amg m104. and replaced the relay. but found out that the relay is already the 000 540 6745 one! waste of cash that was! tomorrow im going to take the air manifold apart and see if there is an obstruction! would anybody recomend doing more work than this? i.e. taking the head off to see if the valves are ok?

plugs are fine changed 4k miles ago!

air mass meter was swaped from my E36, definetly the problem lies with air obstruction. what exactly is the job of the resonance flap? idling issues? or better engine talk?

i know this post is few years late, but would appreciate any reply.

many thanks

paul

<what exactly is the job of the resonance flap? idling issues? or better engine talk?>


The only purpose of the flap is to shorten/lengthen the intake runners. And it is not called for until 3600 RPM.

I would start with codes. Your backfire may be cam advance problem, not air intake....if you suspect valves held open, take a compression test.

A Forum Tip for you...........

You will get a better response starting a new thread than piggy-backing an Archieves Post that is 7 years old...

OVP Location on 1997 C280?
 

Hello Guru's,

I have just purchased a 1997 C280 that cuts off completely from time to time. It has happened 3 times in 3 weeks. Once coming to a stop, next at 45 MPH and the 3rd was at 10-15 MPH.

I read all of the posts and bought the replacement for the 0005405245 Overload Protection Relay; 000 540 6745.

I opened the hood and removed both plastic covers from each side....no OVP that looks anything like the one I bought.

One post says it is behind the battery. My battery is in the trunk.

I am really hopeful this will fit the poblem as a $2,000 wiring harness is not in the cards for me at this time!

Thanks,

Dave