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[:(] Can somebody please please help me with my turbo 98 diesel s300 140 body. Ive already checked every part related to the accelerator and even changed the whole ECU unit and just recently changed the fuel throttle valve. Its been almost a year already since the car stopped running. The engine starts at a very good idle but there is no response when you step on the accelerator pedal. Absolutely no reaction, no RPM therefore the car would not move forward. The car is automatic transmission. [xx(]
 

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1997 S500
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Correct me if I'm wrong but I believe 98 and 99 models had throttle-by-wire. I'm not sure about the diesel though. I know you said that you cheecked everything related to the pedal but there has to be some sort of rheostat connected to the gas pedal. This is just a guess but I would believe that by pushing on the pedal, all your doing is changing some voltage value which the ECU interrperets as a change in throttle. I would also guess that there is some sort of feedback voltage that "tells" the ECU that the gas pedal is functioning properly. Without the feedback signal you would probably get a check engine light. So, my hypothesis is that the feedback loop is still functioning but the actual mecahnical link to the pedal or the rheostat portion of the "module" is inop. I'd change this module. Also, I would assume that starting and idling are taken care of by the ECU- that's why it starts and theres no signal- it's just patiently waiting for a signal from the pedal.
This is just a guess though- could be your tire pressure too[:D]
Good luck and let us know what you find out.
 

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1991 350SDL 2004 G500
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umm yeah...the W-140 diesels where only sold until 1995 and then they where called the S350....do you have an E300 diesel?
 

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w140 s300turbodiesel
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No he has an S300 turbodiesel. Same as I do.

Ok, the scoop on this is as follows: if the temperature outside is very low (below freezing) then pressing the "loud" pedal won't do anything for a minute or so, untill the engine warms up a bit. Well, not exactly NOTHING, it'll do SOMETHING, your revs will go up by a few hundred rpm or so, from 800 to 1000 maybe, but that's it. When the engine has warmed up sufficiently (30 seconds maybe) then it'll respond to accelerator inputs ok. There is another thing to take into consideration. With cold weather, even though your engine may be responding to accelerator inputs your car may still remain stationary. This is due to the automatic transmission oil not being warmed up. It takes a little while for the oil in the torque converter to warm up and then the car goes. This is all winter driving though. As soon as the temperature rises above freezing your "warmup" times drop dramatically.

I hope you were faced with this issue and not something more serious. And yes, your car is drive-by-wire so checking your "gas-pedal" might be a good place to start if your car refuses to go after a minute or so of warm-up time.

P.S. changing your ECU was a bit drastic to be honest.
 
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