If I accelerate with anywhere from half to 3/4 throttle, there's something like a misfire going on. It never trips any codes. Driven below half throttle, which is still more than anyone needs, it's fine. Mash the gas peddle, and the LS1 GTO in the right lane won't be gaining any ground on you
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I watch long term fuel trims, and they hang around 1-2% positive. Short term trim is all over, comparatively.
All the ignition parts are brand new. MAF values get a bit over 240 g/sec. Allegedly it should max out at more like 190 from the sources I've found, but I'd expect that much variation to effect those fuel trims more. No?
Dead spot in the TPS? Easily checked with your scan tool if it shows TPS voltage or percentage.
What year is it? If it has one of the early German drive-by-wire setups, I would definitely be looking in that direction. Went through a very similar ordeal with my E39.
TPS output is weird on my torque PRO app. It's like the computer is sending me a sample every two seconds. Will need to add a graph display and see if that tells me more.
Do you have an oscilloscope? Can you measure the TPS voltage vs time as you open the throttle?
Changed my display for tps to a big graph and drove around awhile. Seemed linear and progressive.
I'm back to thinking it's the maf, I just don't see how the long term fuel correction could be so good.
Did a few WOT pulls and had maf reading top around 250g/sec. That seems way high. Also timing advance is never a positive number. ??
http://lmgtfy.com/?q=ml55
pointofdeparture wrote:
What year is it? If it has one of the early German drive-by-wire setups, I would definitely be looking in that direction. Went through a very similar ordeal with my E39.
Had that issue with an 01 C240. It was position sensor for the gas pedal (I don't recall what it was actually called).
Pull out to make a left turn, step on the gas, and nothing would happen for several seconds...fun
1988RedT2 wrote:
dean1484 wrote:
What is a ml55?
German SUV/money pit. 
And every ML needs this done to it.....
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Ignition parts replaced? So all plug wires too? They have a high failure rate on MBZ.
Also worn engine mounts will cause misfires.
EvanB wrote:
http://lmgtfy.com/?q=ml55
Really????? I ask a simple question and get this crap? WTF 
would hae at least helped if it was ML55
Unplug MAF sensor and drive. See if it still misfires.
The Hoff wrote:
Ignition parts replaced? So all plug wires too? They have a high failure rate on MBZ.
Also worn engine mounts will cause misfires.
plugs wires and coils.
motor and tranny mounts are new.
What year is it? Still thinking it could be DBW-related.
