Erratic Idle

[POLOZ]

Hi guys!

Hopefully somebody can help me out?

Basically my idle on the GTI is slightly lumpy wherby it is evident from the RPM needle as it bounces between 800-900.
Sometimes when stuck at traffic there is a vibration felt through the car and idle becomes more lumpy

I am not sure what the problem is? I have visually checked for leaks 4-5 times and also checked the MAF through VCDS
using this guide on passat world.

To check for a BAD MAF the best way is with a VAG com. Block 002 show air mass from the sensor. At idle the air flow should be 2-4 grams/second. With a wide open throttle run to redline the reading should show up to 170 g/s on a chipped car. Look for jumpy readings in the MAF, which can indicate a problem. More details here: http://www.ross-tech.com/vag-com/cars/fuel-trim.html

if you suspect your MAF is bad, one way to test it is to unplug the MAF, often if the MAF is giving false readings and upsets the fueling. If you unplug it, the ECU will ignore the MAF and run off of baseline tables. Be careful, as a boost leak or a vacuum leak can be miss-diagnosed as a bad MAF, because they will throw off the readings on the MAF. (Air sneaks around the MAF).

I am clearly running out of ideas tbh!

Can it be a spark plug or coilpack etc?

Please please advice as it is driving me crazy

[red6n2]

I very far and between get the same idling problem on my 1.4 6n2

I think the throttle body needs cleaning. Have you tried that, can't be coil as mines not even a year old.

[POLOZ]

I very far and between get the same idling problem on my 1.4 6n2

I think the throttle body needs cleaning. Have you tried that, can't be coil as mines not even a year old.

Throttle body has been cleaned and re-aligned!

Can it be a idle control valve?

[red6n2]

I haven't a clue then, :-/ I was going to clean the throttle body but if you have and it's not solved the problem my mates a mechanic and were giving it a full service early next month and fixing a few bits here and there nothing major but il let you know if there's any progress, the only fault I have on vagcom is lambda sensor needs replacing I have no other faults at all and I doubt very much the idling problem is that.

[POLOZ]

Cheers mate!

Also forgot to mention the erratic idle is more noticable when the engine is warm

[red6n2]

Same I only get it after a while of driving. Just have to wait for my mate to get off holiday then il take a look

[chris meardon]

I used to get this on my gti, there was another thread about it and many others said they got it too.

I thought it was isolated to the polo but I've just bought a golf GT and I have the same again!

[POLOZ]

I used to get this on my gti, there was another thread about it and many others said they got it too.

I thought it was isolated to the polo but I've just bought a golf GT and I have the same again!

Hi Chris, are u experiencing the symptoms as mine?

Can u direct me to the thread please!

Also the car runs fine with no issue fuel issues