mark 2 golf hunting

[shooey88]

mark 2 golf is hunting/fluctuating at idle. when blipping the accelerator pedal and returning to idle the car hunts and idle fluctuates to 1500-2000 revs. tried cleaning the idle stabilisation unit and replacing with three others but same fault appears...any other suggestions?

[onzarob]

Is it a GTI or something else, Injection i would suspect an air leak, throttle body.

[shooey88]

aologies....MRK 2 GTI. tried adjusting fuel air mixture and helped a little but fault still there. checked and tested and no air leaks.

[fraser_edinburg]

check the engine temp sensor

[kow]

Have you cleaned out the throttle body with carb cleaner, set up the tickover as per the Haynes and then check all the hoses on vacuum side if fault persists, also have the CO set on gas analyiser. Is the micro switch that detects throttle at minimum working OK?

[mr brightside]

hello,i've been told that the idle stabilisation valve is so finely made that no amount of cleaning or whatever can rescue it. the advice from people i know is to buy a brand new VAG unit to eliminate it. best guess,good luck.

[1.9mk1golf]

on the back of the throttle body[bulk head side] there is a connector for the ,i think this is either idle control or stepper motor something like that,anyway the connections brake where they plug together ,the wires break,try that

[lvbug]

Ive have this problem with my PB engined GTI aswell , I did find one of these wires broken(idle switch) so I repaired it. The fluctuating of revs has stopped! but now theres another problem it idles high ; about 1000 - 1200rpm. Ive tried cleaning the idle stabilisation valve but no difference! It does idle ok after you put a load on the engine.

[1.9mk1golf]

does the engine do this from cold and then when you rev it ,it settles down. sorry need a little more info

[lvbug]

No its mostly when its warm or hot and just when you let your foot off the throttle to let it idle! But once you put a load on the engine eg turn the steering or put all the electric consumers on : it settles to normal idle speed ie 850rpm ! Sorry I dont mean to be distracting from the origional thread