Engine Revs Up And Down

[AlexHotRod 1 1 Cars]

Hi guys,

 

i have this problem on my 205 GTI 1.6 the engine revs up and down till it turns off ...honestly i don't know what could be, i've cleaned the throttle body but nothing changed.

 

Anybody had the same issue?

 

Thanks Alex

Edited August 27, 2014 by AlexHotRod

[selfyyy 4 1 Cars]

Have you tried cleaning the idle air control valve?

[AlexHotRod 1 1 Cars]

Have you tried cleaning the idle air control valve?

 

No because i don't know the right way to do it and were it is located exactly

[selfyyy 4 1 Cars]

Im not certain where they are on a GTI so you would confirm with someone else, have you checked for air leaks also?

[AlexHotRod 1 1 Cars]

Thaks for your help i will wait for other replay and check for air leaks, i didn't do that

[jackherer 543]

When you cleaned the throttle body did you fully unscrew the idle air bypass screw? If not try removing it and cleaning it until it shines!

[AlexHotRod 1 1 Cars]

When you cleaned the throttle body did you fully unscrew the idle air bypass screw? If not try removing it and cleaning it until it shines!

 

No i did a quick clean spraying some throttle body cleaner because honestly i don't know where the idle air control valve is, looking at the throttle i see a little plastic square hold with two screws in the front part... i think it's that but i didn't touch it because it's the first time i work on it and i have no experience... and when i google "idle air control valve" i see most of the time it has a different shape more like a cilinder.

A picture of it will help me a lot i think ​

I have a GTI 1.6 85 kW if this info can help

[jackherer 543]

http://205gti.com/downloads/Chapter_01_Routine_maintenance.zip

 

Go to page 19 "Multi-point fuel injection models" and look for the idle speed air screw adjustment. NOT the mixture adjustment screw which is on the same page, leave that alone!

 

The black plastic square part is the throttle position switch, your problem might be caused by a fault or bad adjustment of the TPS but clean the idle air screw first.

[jackherer 543]

You'll find page 3 of this chapter useful too: http://205gti.com/downloads/Chapter_04c_Injection.zip

[AlexHotRod 1 1 Cars]

Thanks Jackherer for you help, just one question can i fully unscrew the idle air bypass screw without problems or i have to be careful about something?

[jackherer 543]

Yes, take it all the way out and clean it until it is spotless, be careful to not drop it and lose it

 

When you refit it obviously you'll need to screw it back in all the way then wind it out a little bit and then finally adjust the idle speed with the engine running.

[AlexHotRod 1 1 Cars]

Problem solved thanks jackherer, now the rpm are stable. it still revs up and down a little when the engine is cold but just for a couple of seconds and it no more turn's off

[jackherer 543]

Do you know when your fuel filter was last changed? If not put a new one on and it might just smooth out that first few seconds when it's cold.

[AlexHotRod 1 1 Cars]

No i don't know i will change it to be sure ​