Coilpacks didn't fix the problem :(

[Scotsman]

I was having misfire/hesitation under acceleration so just fitted new coilpacks - which seemed to fix the problem after I took the car out for a 5 min drive - however, then didn't drive it again until today as I was waiting for new engine cover grommets as two of mine were knackered.  Just fitted them, nice tight fit now and took the car out.

Still bad misfire/hesitation on part throttle when accelerating 

Car starts fine, idles great, smooth when driving on part throttle keeping a steady speed, but any acceleration (worse in high gears at low speed) on part throttle causes misfire/hesitation.

Any ideas on cause? (aside from one of my new coilpacks being the issue).  Spark plugs? fuelling?

Many thanks
Richard.

[S2 Ant]

Is your car running the stock map or has it been remapped?

[Scotsman]

Running the stock map - though for interest when I flashed it with Bluefin 4 months ago I had some hesitation on full throttle, so just flash it back to normal and it was fine (until now). A couple months before that when I was running the bluefin map for a few days I didn't have any problems.

Didn't keep the bluefin map on the car as it was going to be a £200+ uplift to my insurance and I didn't think it was worth the cost at that time (I'm only paying £190 fully comp).

[PDT]

 a datalogging session should show up the fault.

[vRS Carl]

I had this problem recently and it was the Spark plugs.

This was after a data logging session which wouldn't show the fault as the car doesn't log Spark Plug faults permanently. It will only show up when you log blocks 015 & 016 but it resets itself all the time.

I'd suggest getting a new set of plugs and try that

[Scotsman]

Thanks guys - I'll try the spark plugs first and if no joys after that then I'll go to the garage.

I think the right type is 06H 905 611 - though I'll have a look through my old service receipts to see when/if they were last changed (2005 car with 37k).  Are they easy to change on the GTi?

Cheers
Richard

[Scotsman]

Just found this guide on how to change them:

http://www.golfmkv.net/blog/archives/9#

[vRS Carl]

Piece of pi55 to change.

Remove engine cover, Disconnect and remove coilpacks, Remove old Plugs, Insert new plugs, replace coilpacks & re-connect Coilpacks, Replace engine cover, Job Done

The correct Part no. for a GTi is - 101 905 631 H

[Scotsman]

Piece of pi55 to change.

Remove engine cover, Disconnect and remove coilpacks, Remove old Plugs, Insert new plugs, replace coilpacks & re-connect Coilpacks, Replace engine cover, Job Done

The correct Part no. for a GTi is - 101 905 631 H

Thanks again - gives me an excuse to buy the correct tools for the job too :)

Ordered from the local dealer and picking up on Monday - £43.26 for four.

[Hurdy]

If this doesn't sort it then it could be either the PCV or the N75 valve.

[Scotsman]

If this doesn't sort it then it could be either the PCV or the N75 valve.

Thanks Hurdy.

[jmspear]

#2 PCV that what is was on my GTI, cheap and easy fix to replace, with new upgraded PCV from VW

[Scotsman]

#2 PCV that what is was on my GTI, cheap and easy fix to replace, with new upgraded PCV from VW

Thanks - I'll change that at the same time I'm doing the plugs - I've just read that it's recommended anyway to get a later revision.

Here is a handy guide I found on fitting them: http://vagdrivers.net/forums/index.php?showtopic=40537

I think the correct PCV part number is:   06F 129 101 L 

Cheers
Richard

[DelB]

Hi Richard. Sorry to hear you're still having an issue with the car, but good to know it's not the coilpacks! 

I e-mailed Jim at Star Performance at the tail end if last year to describe the same symptoms and he said it sounded like 'the valve at the top of the engine'. I haven't yet had time to go and see him about it, bit will get him to attend to it early next month as the car is due a service then anyway. Is this 'valve at the top of the engine' the PCV which is mentioned in Hurdy's post?

Cheers mate. 

[Scotsman]

Hi Richard. Sorry to hear you're still having an issue with the car, but good to know it's not the coilpacks!  

I e-mailed Jim at Star Performance at the tail end if last year to describe the same symptoms and he said it sounded like 'the valve at the top of the engine'. I haven't yet had time to go and see him about it, bit will get him to attend to it early next month as the car is due a service then anyway. Is this 'valve at the top of the engine' the PCV which is mentioned in Hurdy's post?

Cheers mate.  

Yes, that's the PCV value - photo of it here: http://vagdrivers.net/forums/index.php?showtopic=40537

Just phoned the dealer looking for one and it appears its currently on back-order - so looks like I've trying the plugs first!