High idleing Mk2 Digifant?

[Reno5GTT]

Hi, i have a 1987 Mk2 Golf GTI 8v with digifant fuel injection. As soon as i start the car it revs to full throttle with no input on the pedal?! The problem has been getting progressivly worse to the point that i cannot drive the car. I have checked that the cable isn't sticking and there are no signs that the throttle mechanism is sticking or jammed in any way. I have checked and cleaned all of the electronic connectors with no luck. I am a student and can't afford to put in into a garage to have it checked out. Please help!

[slot]

Theres a small screw just below the throttle mech on the inlet ,make sure this is screwed in properly !!
hope it helps  

[wallpaper_01]

mine is doing kinda the same thing, when i start it, it goes high then the revs go down to stall then it gets pulled back up again and it just keeps going up and down. mine is an 88 digifant

[Blue MK2]

^^^ probably air leaks. check the grommet ontop of the rocker cover (seals the air breather to the rocker cover) you probaly dont have one

[davidhawkins_78]

It'll be and Air leak or shagged 'closed' throttle position sensor or ISV or temperature sensor... probably a combination of a few i'd say though.

Search for forum for more details as these are common problems.

Hope you get it sorted ....

[Reno5GTT]

Hi again, i already checked the idle screw and breather gasket on the rocker cover. I have also checked for air leaks and just fitted a new temp sensor (after the problem started) but this did nothing. I can also here a buzzing from the ISV with the ignition on (this means it is working?) disconnecting the wires make little differance.

Where can i find the throttle position sensor?
Is it the switch on top of the throttle body?
Can i test this before replacing it?

[davidhawkins_78]

Unplug the isv and see what happens ... do the revs drop?

The ISV might be sticking open and raising the revs; yes the buzzing means it's working, but necessarily correctly.