Throttle problem
Thread Starter
Newbie
Joined: Mar 2006
Posts: 2
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Mercedes S430
Throttle problem
When I press my throttle pedal quickly the revs die right down, yet if I press slowly it will build up to high revs ok. The same in park, nutral and whilst driving. Kicking down to overtake just brings the car to an almost stop.
Should I look at the pedal assembly or the throttle position sensor in the engine bay?
Should I look at the pedal assembly or the throttle position sensor in the engine bay?
Newbie
Joined: Mar 2006
Posts: 2
Likes: 0
From: Singapore
Mercedes S500
hello shander...The problem lies in you air mass sensor. Have it cleaned and try again. If you cant then you have to replace it. Your model is V8, twin spark model for each cylinder?. If so check for spark leaks. Do this at night with all lights in your garage switch off. with air cleaner element and hosing removed. this will enable you to see which leads are leaking current. Visible just as the engine dies. Direct ignitor means that you only change that ignitor. Each ignitor controls 2 plugs on different cylinders. However as at this moment you check you air mass sensor. Unplug it and see if the engine behaves the same. If the engine behaves the same.... its confirmed the the sensor has to be replaced. FYI: your engine now running on emergency mode. Its trying to say, go home or visit workshop. Its designed not to let you leave stranded on the road...! Cheeers pal.
Newbie
Joined: Mar 2006
Posts: 18
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try cleaning the throttle valve maybe got stucked thus preventing full opening of the throttle valve.
vapor lock could cause such behavior too. try using different fuel.
and the ever notorious MAF as what vijay indicates.
your car doesn't overheat?
vapor lock could cause such behavior too. try using different fuel.
and the ever notorious MAF as what vijay indicates.
your car doesn't overheat?
Newbie
Joined: Sep 2002
Posts: 10
Likes: 0
I had exactly the same problem with my 2001 S430. The car did not accelerate immediately when the gas pedal was depressed. It slowly picked up to speed. At the beginning, I thought it was due to a bad AMF sensor so I bought one and popped it in. It did not solve the problem. OBD II code reader pointed to P120 code. The pedal position sensor was problematic. Bought a new gas pedal assembly for $200 at the dealer. Replaced it and it ran fine.
Now I have an extra AMF just sitting there.
Now I have an extra AMF just sitting there.
