Car bucks and jerks when cold below 2000 rpm

[Reedy]

When ever the car is cold and I am driving or stood still just feathering the throttle the revs seem to do what they want to do which is jump around. When stood still they just jump around until I rev over 2000rpm, when driving this causes the car to buck and jerk.

Anybody any suggestions regarding what to test check or replace.

Once the car has warmed up the symptoms are not nearly as bad and hardly noticeable.

Cheers.

[Lucas_R]

Is it misfiring? If so, it will be the ignition coils which are a common failure on these engines. Good news is that they are not very expensive and can be had for about $150 (full set) delivered from USA. Be prepared to pay double that (at least) to source them from your local VW.

[grtuned]

Let the car warm up before driving all cars will idle differently when there cold it's just the programming of the ecu they all have a warm up phase if you feel it's ok when its hot this may be why.

[Reedy]

Thanks for the response. Symptoms have developed on the way home. I have been getting a little flutter of the rev counter when moving and I press the throttle. These has developed into when at idle and I push the throttle it kind of misses a beat and then revs. These are the exact symptoms I had a year ago and it turned it to be the purge valve and charcole canister. These symptoms maybe related to the bucking I have when cold. Car is booked in for next Tuesday. Don't really want to be buying a new purge valve and charcole canister every 20000klm?? There is a thread started by me some on this forum about this issue I had.

I'll keep you all posted.

[Lucas_R]

First i've heard on here of a purge valve (?) and charcoal canister having to be replaced, so hopefully that was a one-off. I'd say ignition coil packs are the culprit this time.

[Reedy]

Back on the 12/12/12 I had a discussion on this started by me I think titled engine flutter or rev counter flutter.
I've just fault tested my car with my little cheap tester and faults are:
01089
P0441
After researching these they all point to the purge valve and charcole canister. I must be the only gti owner to be having this problem. I thought it was a year ago but I had a new one fitted last December so 8 months ago. Not good.

[Lucas_R]

Ok well the purge valve and charcoal canister are related (both part of the emission control system on the engine) so makes sense that you are getting errors for both.

Given that this has happened twice in a short time frame, id say it's either incredibly bad luck, or more likely, another part in the emission control system that's faulty and causing these parts to wear out faster than they normally would.

Some info that might help - turns out in this case it was the "fuel pressure limiting/regulator valve" that needed replacing. Another common culprit seems to be a vacuum leak (pipe or connection is cracked) or a pipe is blocked.

VWVortex.com - Stubborn P0441 code

16825/P0441/001089 - Ross-Tech Wiki

[Reedy]

Thanks mate, I hope that because its been a short time the VW will perhaps look a little deeper, or I may suggest they look deeper as main steelers can be lazy... I'll keep you all posted.

[Reedy]

Faults cleared by my maxscan and half the problems are gone. Still got the bucking and jerking below 2000rpm when cold but the purge n80 valve symtoms have gone or appeared to have gone for now. This thing is driving me crazy!!!!!!!! But still love it.

[The One]

Get these ALOT. Seen guys replaced N80, charcoal canister and breather valve on rocker cover all as a set, usually just for $$. The culprit is 9 times out of 10 the N80, charcoal canister very rarely will block up in a cars lifetime, let alone a second time after its already been replaced. You said all that stuff was fitted 8 months ago, take it back to where it was fitted tell them it's back again, remember 12months part and labour warranty mate. Goodluck.