With engine rev, anybody have surging?
Thread Starter
Newbie
Joined: Apr 2007
Posts: 24
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From: Virginia US
95 C36 AMG
With engine rev, anybody have surging?
My C36 has developed a strange surging problem while sitting in idle. When in park and revving engine, when RPMs hit 4000, engine starts fluctuating RPMs up and down on its own while holding accelerator steady. Also have the problem that while driving and if I have to accelerate quickly, the next time I am idling at a stop light, the RPMs drop out and car acts like it is going to stall out, but then come back up.
Anybody have this problem? Know where to start?
Anybody have this problem? Know where to start?
Newbie
Joined: Aug 2007
Posts: 19
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From: England - Hampshire
Black C43 AMG' 1999 - 2x Vauxhall Cavalier Turbo's - 1 Vauxhall Cavalier GSi2000 4x4 -
not with my C43 AMG, but i have with my Vauxhall Cavalier Turbo, and it was said that my IAC (Idle Air Controll valve) was knackered. Not sure about MB's yet, as im a newbie to MB's 
Joby.
Joby.
Newbie
Joined: Aug 2007
Posts: 19
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From: England - Hampshire
Black C43 AMG' 1999 - 2x Vauxhall Cavalier Turbo's - 1 Vauxhall Cavalier GSi2000 4x4 -
can u quickly explain to me about this wiring harness, whats it about? sorry new to all these names n things!
Thanks
Joby.
Thanks
Joby.
Thread Starter
Newbie
Joined: Apr 2007
Posts: 24
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From: Virginia US
95 C36 AMG
Wiring harness just replaced in May 07 - burnt up my ECU. Didn't realize that my year AMG had an issue with "biodegradable" wiring harness covers. Ugh. After replacing wiring harness, ECU, ECM valve, plugs and plug wires, car didn't react this way. Has started back up recently.
Oopps EGR valve not ECM valve. Also replaced the MAF sensor. All for naught - the ECM was toast - wiring system had burnt it up. After replacing wiring harness and ECM, replaced plug wires. Replaced fuel filter today.
Oopps EGR valve not ECM valve. Also replaced the MAF sensor. All for naught - the ECM was toast - wiring system had burnt it up. After replacing wiring harness and ECM, replaced plug wires. Replaced fuel filter today.
Last edited by drewsome2; Sep 23, 2007 at 09:56 PM. Reason: too much to drink, not enough $ to fix car probs
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I have the same problem.the cars idle is very rough when you stop at robots sometimes the car switches off and wont idle,you got to keep the revs up the take off from the robot,then at the next robot the car idles fine.I replaced one plug wire which was touching another and still the car is very rough.could this be mechanical or electrical?
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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
Could be
your cps is going south on the one issue.Scan your codes.On the other 4000 rpm issue most of the benz have a neutral rpm limiter separate of the governed speed limiter.it will cut spark to the engine in random order to prevent over revving at park and neutral position.Feels like it hits a rev limiter?
ohlord
ohlord
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Thread Starter
Newbie
Joined: Apr 2007
Posts: 24
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From: Virginia US
95 C36 AMG
Just a quick update - replaced coil packs and that seemed to do the trick! No more dropping out or surging on revs. Car has 120K+, and not sure of what maintenance was done prior to my purchase. Now going through and dotting i's and crossing t's for service, to make sure nothing else whacky out there.
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1967 Morris Cooper "S", 1983 911SC, 1997 Toyota Tacoma, 1999 HD FXSTB, 1998 C43
How many coil packs does that car have and how many did you end up replacing? The C43's have a couple too many...with 100K on mine, a possibility in the future.
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Yep...understand that it is somewhat normal... I have used Seafoam injector cleaner and mine has improved (1 bottle for tank). I'm also going to try MAF cleaner (Advance Auto Store) to see if that helps. I'm guessing it is the sensors and ECU not knowing exactly what is going on... I also think my car runs 'richer' than it should... good luck.
