Low mpg, Flat spots and 'lumpy' idle!

[Gabriel2202]

Hi there, i have posted this problem before and got some good feedback so thanks alot!  but after having a full service, clean throttle body and check over at the garage I have a better idea of the symptons so hopefully it will give a clearer indication of the problem...

I have an x reg Mk4 golf 1.8t aum

When idle the revs are 'lumpy' and it happens more when im driving and pull up at traffic, i.e. when the engines hot as opposed to when i first start it. in fact it cut out at traffic lights coming off the motorway yesterday  :embarassed:

When driving it doesnt pull as well as it should having flat spots at 3-4000 rpm and giving an average 26mpg on the motorway?! Often the next day after a drive i.e. leeds to sheffield it turns over alot before it struggles to start. its had an '0ct - tuning' remap and a turbo boost gauge but no other mods.

I want to start tuning this car but have seen from reviews at r-tech and carbon chiptune that nothing can be done if it has existing problems so really want to get them sorted. I have been told maybe a check of the sensors and MAF could be the cause? or overfueling?

Any help is really appreciated, this is my first golf and after being neglected by its previous owner i just want to restore it to its former glory, and then make it a hell of alot better!!  

Thanks!

[Wayne]

Could be a coil pack issue

[Agreeable Slick]

It sounds more like a coil pack beginning to fail, see if you can get it on VAGCOM, if not, turn engine off, remove a spark plug then fire the engine up, do in sequence, if removing one doesn't change the running pattern then it's that plug. Then do the same for the coil packs if the above happens when one is removed then it's a coil pack.

[Gabriel2202]

Ok cheers, I just had new spark plugs, where are the coil packs located? Are they car specific?