Throttle Hangs

[Guest fredt]

Today on the way home the revs have started to hang on releasing the pedal the revs drop back slowly and hang around the 1500 RPM mark and then drop back to tick over!

so far I have cleaned the throttle body and the hoses to it for good measure! found a split in one of them! also cleaned and lubed the throttle body linkage and cable while I was there

also cleaned a couple of other valves on hoses around that area, but dont ask which ones as I didnt take much notice of them as it was getting dark and I wanted to get it all back together before it got to late!

still the revs hang :( next step is check for air leaks around the intake system manifold, throttle body etc.............

unless of course someone else can suggest something else to take a look at? that doesnt mean me stripping it all down again :(

[Guest DanB]

Fred, I didn

[Guest fredt]

Its only started on mine today :( just when I get time off work and have planned a few days out with the kids it goes tits up! :( its still drivable but annoying! oh well time to get the GTI out the garage and blow the dust out the exhaust! kids wont be happy due to no DVD and the exhaust being rather loud :( oh and the suspension is very hard! :(

[charles]

the mine does it too. when driving and de-clutching it drops back to 1500rpm.

Only when the car fully stops the rev drops to back to tickover.

[djacks42]

I had this problem a few weeks ago. You need to remove the ICV (idle control valve) and rinse it out with some WD40. The little spring gets all clogged up and screws up the revs. It's in the TIS disk and is a 20min job. Just wip off the plastic rail with the multiplugs at the top of the engine and it should be visible just below it.

[Guest fredt]

While replacing the hoses to the throttle body last night I found a couple of splits in the conveluted part :D also the one way flame arrester valve on the crank case breather had come apart :D several self tappers later and thats in one peice again :rolleyes:

the hose will be in the dealers tomorrow morning and on the car ten minutes later! the ICV is next on the list to be cleaned, but after the engine cools downs! just got back from Warwick castle, in rather a rush as something on Ebay was ending tonight! so its rather warm under the bonnet at the moment :D

[Guest fredt]

Right finally got the hose :( only problem is that it wont fit due the brake fluid resevoir being in the way! the old hose has a preformed dent in it to miss the brake fluid resevoir

while I at it I have replaced any hose that looks a bit suspect and am still looking for the ICV :( I dont have one as far as I can see! we think it may be built into the throttle body! so we have reset the throttle bodys parameters and once its all back together we shall see how it runs?

[Guest fredt]

well its back together, and its slightly better but not perfect :( oh well till I get round to totally removing the throttle body and cleaning it, it will have to do

from reading up on the ICV it appears I dont have one, the tick over is controlled electronically by a sensor in the throttle body, well I wanted a reason to change it! now where's that site that sells ported throttle bodies for the VR6 :(

[Guest neil_wiles]

Fred

 

I have experienced a similar problem on a rather sporty Nissan (oops sorry didnt mena to swear hope this post isnt reported) 350Z and the cause was an intermittent track on the accelerator position sensor (pedal varistor) only on one track (they have two) and this didnt cause the MIL to illuminate as the programming of the ECU allow for intermittent signal but as with the VW ecu it will control the engine decelerration rate and idle speed as if no accelerator was present until you apply movement to the pedal so the ecu can re-adjust its readings and resume control.

 

May mean a pedal check with a DVM or Scope if you have one.