1988 Mercedes Benz 300e Weak / Hesitant acceleration

AZZOUZ

MEMBER
1988 MERCEDES BENZ 300E
6 CYL
2WD
AUTOMATIC
90,000 MILES

Thank you for answering my question.
Just bought this car. Previous owner said, I believe him, he installed a NEW fuel distrubuter, and 2 'filters" that go with it. The car most of the time, hesitates in acceleratin, esp. From a standstill. I have to depress the accelerator almost all the way down, then it would JERK and accelerates fast, that happens like 7 out of ten times, the 3 remainiing times, can accelerate normally, but at 30 or 40 mph, would / could go sluggish again, and have to depress the accelerator to get it to go. At regular highway speeds, no problems, UNLESS I lift my foot from the pedal, then I might experience the same thing. Experimenting, when at a light, I kept my foot a lil heavy ( 1000 Tach), and it started GOOD, no hesitation. Wondering what else could it be, aside from the fuel distrubtor that he changed, I put new plugs (old plugs were very black, been told running rich). Appreciate your advice.

2 Replies

2CARPRO JACK

MECHANIC
11,533 POSTS

I have forwarded your link to our resident M/B expert. He should be with you shortly

Thanks for using 2CarPros. Com

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Monday, February 9th, 2009 AT 7:38 AM

GFIMOTORCARS

MECHANIC
673 POSTS

From what you are describing I would also be looking at the possiblity of either failing fuel injectors, a failed MAP sensor, or a failed Throttle Position Sensor (TPS). All of these failures can cause what you are describing. However injectors failing will usually cause more predictible behavior. Both the TPS and MAP sensors will fail as you describe esp. On start up from a dead stop. If the MAP is not reading correctly you can also see a rich mixture develope due to this. Also a failed MAP will cause irradic behavior from a dead stop similar to what you describe. As for the TPS, this is what your vehicle uses instead of a cable to transmit the motion of your foot to the throttle body. This may be why you are having to put the pedal to the floor before the sensor picks up the position. When the sensor fails it tends to have dead spots in the readings, and will only respond at particular positions. Do you have any check engine lights on?