acc. pedal woes ???
Thread Starter
Newbie
Joined: Sep 2008
Posts: 6
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1990 420sel
acc. pedal woes ???
The acc. pedal feels like it is sticking a little bit when you first hit the pedal. Then while driving down the road I am having problems with the pedal doing nothing at all. I have to pump the pedal before it will grab. It will usually do it 4 or 5 times on my 15 mile journey to work. I lubed up all the linkage but it didnt help. When I move the linkage by hand, it seems like maybe the throttle body ( or whatever the last bit of linkage is pulling on) is what is not grabbing. The pedal resistance feels the same but the car doesnt rev up. The first time this happened I thought the car had died on me because the car is so smooth and quiet going down the road.....I know my description makes no sense but I dont know how else to describe it......Jamie
Junior Member
Joined: Aug 2008
Posts: 19
Likes: 0
From: Lewistown, PA
1990 560SEL
Throttle
I would recommend disconnecting the long control link that runs under the air cleaner and disconnecting the control link to the cruise control module and verify that the link down to the throttle has no play and is moving smoothly. Clean everything well and lubricate as you re-assemble if there are no problems.
If you find no problems at the front side then move to the rear of the engine. Many have a spring loaded control link that keeps the throttle assembly from being forced past the stops. If this has started to give out then it may allow more "play" in the pedal before getting throttle response. I've never seen one bad but it is something to look at. Try moving the pedal control by hand from under the hood and ensure the complete linkage down to the throttle plate is moving as the pedal control begins to move. If not, you'll need to find what is broken or needs adjusted. Just be sure everything moves freely or you could get a stuck throttle and bad things could happen.
Good luck.
If you find no problems at the front side then move to the rear of the engine. Many have a spring loaded control link that keeps the throttle assembly from being forced past the stops. If this has started to give out then it may allow more "play" in the pedal before getting throttle response. I've never seen one bad but it is something to look at. Try moving the pedal control by hand from under the hood and ensure the complete linkage down to the throttle plate is moving as the pedal control begins to move. If not, you'll need to find what is broken or needs adjusted. Just be sure everything moves freely or you could get a stuck throttle and bad things could happen.
Good luck.
Thread Starter
Newbie
Joined: Sep 2008
Posts: 6
Likes: 0
1990 420sel
I think I fixed it, I barely adjusted the linkage so that it wouldnt close all the way. It was sticking for some reason. The thing where the pedal was moving but doing nothing, was because it was sticking and the long piece of linkage under the breather was bowing real bad. It was bent so I had to straighten it out a little. I will be adding another thread on the idle today so be on the look out....Thanks Jamie
Junior Member
Joined: Aug 2008
Posts: 19
Likes: 0
From: Lewistown, PA
1990 560SEL
Bearing on non-linear control plate
One other thing to look at is on the oddly shaped plate on the passenger side on the back of the engine where the long link connects. There is a small plastic bearing that rides inside of the opening of the non-linear control plate. If this bearing has broken and been lost it will create excess play. You can adjust this play out but the movement will not be as smooth. Be sure you haven't lost this bearing. I am sure replacements are available if so.
