Engine Throttle goes up wildly to maximum by itself when accelerating above 3500rpm

[Vikash Joory]

Hi All, I am having a very worrying issue with my Audi A4.
Model is: Audi A4 B5
Year is: 1997
Engine : 1.6 Gasoline.


The engine throttle goes wildly up to 7000/8000 rpm whenever the accelerator pedal is pressed to above 3500 rpm - by itself. The only way to get the throttle down is to switch of the engine(turn ignition key to off position)!


To restart engine without the wild self-acceleration - we have to play a ittle with the accelerator cable under the hood where it connects to the throttle device.


I have performed a diagnostic of the engine an obtained the results attached.


Anyone has any idea or came across such an issue .... please let me know.


It is quite dangerous to be driving it at the moment since it throttles wildly up to maximum throttle revolution 7500/8000 rpm on its own whenever we accelerate to above 3500 rpm and does not return to idle at all!


Thanks for any feedback




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[Vikash Joory]

Hello - I have gone through a bit of materials available on the net. Could the problem I am having being related to the a dirty or clogged throttle plate(butterfly) inside the throttle body? As would seem that the throttle plate is not coming back to its initial rest position and I have to wiggle the accelerator cable a bit for it to return to its initial rest position.

[Rob69]

Check your cable can return when the pedal is released, it sounds like a mechanical issue, sticky cable.
lots of codes there as well. sort the cable then clear the codes and see what comes back on subsequent scan.

[Vikash Joory]

Hello ... the cable wire does return to its idle state when pedal is released. However, on top of the cable can there is a metal thing that stays in the accelerated position. To reset it .. have to giggle the cable wire to and throw before the metal thing on top of the cable can returns.

[SammoVWT]

Sounds like the spring shut pulley type of device on the side of the throttle body, which the throttle cable is attached to is gummed up or broken. Check that the rubber/plastic shaft that the cable runs through hasn't perished to the point where its snagging.

Pedal getting stuck at all and not returning fully?

You should be able to check this on a cable driven car with the engine off to check the movement

[Vikash Joory]

Sounds like the spring shut pulley type of device on the side of the throttle body, which the throttle cable is attached to is gummed up or broken. Check that the rubber/plastic shaft that the cable runs through hasn't perished to the point where its snagging.

Pedal getting stuck at all and not returning fully?

You should be able to check this on a cable driven car with the engine off to check the movement


The throttle block is as the picture below - (this is a picture off the internet) - but is similar to this one:

28710

So i believe it is not entirely cable activated - it seems there is a motor connected to the throttle plate.
(picture was taken from this post: http://www.audiworld.com/forums/a4-b5-platform-discussion-1/removing-cleaning-your-throttle-body-1-8t-faq-w-pics-151070/)