Mk 2 Gti Idle Probs??

[DOUBLECAB]

Hi Guys............have a 1991 Mk2 GTI 8v that won't go back down to the 900 odd rpm idle when one pulls up at the traffic lites.....idle stays at around 1500rpm unless I put the foot on the break and let out the clutch while in gear.........then it drops to the idle speed.

Any ideas please??

Thanks ..............doublecab.

[h100vw]

Idle screw could have backed out. They have a habit of doing that once in a while.

It's on the back of the throttle body. You should take it out anyway and clean it up as it will be covered in oil residue. Some WD40 would be good to clean it with or brake cleaner.

Then you will need to reset the idle. There is a special way of doing that, which I can't remember completely. It does involve disconnecting the blue temp sensor in the top hose to the radiator. Read up in the haynes manual or google it.

The other thing it might be is a bad idle switch on the throttlebody. I'd check the idle screw first.

Gavin

[Peter Jones]

The idle screw gets loose after a while due to it's o ring wearing out. I got a handy pack of o rings from bunnings for a few dollars and replaced it. No problem with variable idle speeds since.

Pete

[moto]

I

Then you will need to reset the idle. There is a special way of doing that, which I can't remember completely. It does involve disconnecting the blue temp sensor in the top hose to the radiator. Read up in the haynes manual or google it.

Gavin

Disconnect the blue temp sender
Disconnect the breather hose and block it off (masking tape is good)
Start the engine and rev it over 3000rpm 3 times (resets the ecu)
Let the revs fall back and adjust the idle screw to a nice slow even idle
Rev the motor 3 times past 3000 rpm and shut it down
Reconnect everything
Restart it. You may have to do some fine adjustment on the idle screw again.

[Jmac]

Mate can i suggest you take off your idle stabilisation valve and soak the insides with Shellite till its spotless. These are notorious for causing idle problems on Gtis. Then Set up the engine tuning by diconnecting the blue temp sensor, rev up 3 times to 3000rpm then adjust settings. Put the sensor back on give 3 more 3000rpms and all will be sweet
Cheers