Hesitation under load !!

[mk5fsi]

Hey guys over the past couple of days, I've being getting a wired problem that's completely random. What happens is when i accelerate or demand more power i get a sort of hesitation like there is not enough fuel being injected, and it doesn't rev out as fast. It feels like its being held back, the strange thing after a couple seconds the power comes back on and its fine for a couple minutes and then it starts again. What's also strange is while this is happening if i take my foot of the gas, the revs jump up occasionally maybe 200-300 rpm, and feels very jerky, also other times when i take my foot of the accelerator the revs stay constant and don't start dropping down like they normally do. Also if i brake while its happening the car feels like it want's to continue surging forward like someone is pressing the accelerator slightly while braking, it's very annoying. This happens mostly between 1500 and 4000 rpm under load and accelerating in all gears. Funny thing is that under WOT it doesn't happen only very rarely, it idles perfectly and if i rev it while in neutral the car revs perfectly no hesitation. It's a very random thing it will happen for a couple of minutes and then run normally. If i turn the car off and turn it on again it sometimes cures it and after a couple of minutes it starts again. If i turn the car off for more then 15mins, then it completely cures the problem until the next time. its very strange, any ideas? Also no lights on the dash come on while this happens, The car is a 2005 MK5 golf 2.0 FSI Manual, Thanks.

[h100vw]

Regardless of the symptoms, the first thing to do is scan the car for faults with VCDS or some other scan tool.

Could be a handful of things, just not worth the time speculating.

There's a sticky in ecu tuning with a list of people with leads that are willing to help.

Gavin

Hey guys over the past couple of days, I've being getting a wired problem that's completely random. What happens is when i accelerate or demand more power i get a sort of hesitation like there is not enough fuel being injected, and it doesn't rev out as fast. It feels like its being held back, the strange thing after a couple seconds the power comes back on and its fine for a couple minutes and then it starts again. What's also strange is while this is happening if i take my foot of the gas, the revs jump up occasionally maybe 200-300 rpm, and feels very jerky, also other times when i take my foot of the accelerator the revs stay constant and don't start dropping down like they normally do. Also if i brake while its happening the car feels like it want's to continue surging forward like someone is pressing the accelerator slightly while braking, it's very annoying. This happens mostly between 1500 and 4000 rpm under load and accelerating in all gears. Funny thing is that under WOT it doesn't happen only very rarely, it idles perfectly and if i rev it while in neutral the car revs perfectly no hesitation. It's a very random thing it will happen for a couple of minutes and then run normally. If i turn the car off and turn it on again it sometimes cures it and after a couple of minutes it starts again. If i turn the car off for more then 15mins, then it completely cures the problem until the next time. its very strange, any ideas? Also no lights on the dash come on while this happens, The car is a 2005 MK5 golf 2.0 FSI Manual, Thanks.

[mk5fsi]

Thanks Gavin, i will look into it.