Hesitation issue still not solved... can anyone help?!

[mattchaps]

After being hopeful and finding info on here I thought I'd solved my GTI's hesitation issues, but after more replacing parts it's still there.

The problem: When cold, the car has a serious hesitation issue under load below 2,500rpm, feels like misfires or a lack or fuel. Idle is also a bit lumpy. But take her over 2,500rpm and the hesitation seems to disappear but dip below it again and it returns. However, once she's warmed up there seems to be no hesitation at all, at any rpm!

Items replaced: Plugs, Coils, PCV valve. Have also disconnected the battery for half hour to reset the ECU.

Results so far: No Change!

I haven't been able to get it scanned for errors yet, and I'm not paying VW £60 just to scan it for me when they are still unlikely to know how to fix it. Hopefully vrsCarl will be able to come up but that's not going to be until July.

If anyone knows what else it might be, I'd be everso grateful as I really want/need the car to run right because it's getting me down now.

Thanks, Matt

[Andy]

might be a long shot but a friend of mine had the same issues and changed every thing to cure it and it turned out to be the wiring loom to the coil pack..after we found the answer on here

[bacillus]

I haven't been able to get it scanned for errors yet, and I'm not paying VW £60 just to scan it for me when they are still unlikely to know how to fix it.

Have you looked to see if any member with a vcds cable on here is located nearby to do a scan for you?

[mattchaps]

Should have said, car is an 07, done 80k miles, No mods at present.

I haven't been able to get it scanned for errors yet, and I'm not paying VW £60 just to scan it for me when they are still unlikely to know how to fix it.

Have you looked to see if any member with a vcds cable on here is located nearby to do a scan for you?

Yep, VRSCarl is the closest and have already been in touch with him but he can't do anything until July.

[martziniuk]

I've had this from standard. When I first bought the car I occasionally got the cel light up pointing to cylinder 3 misfire, I replaced the coil pack but it made no difference. I run the car on high octane 99 Ron now which has helped a lot, it's still not perfect but it's a lot better and no cel. As soon as it reaches 90 c water temp it's fine. I have put it down to carbon build up on the intake valves but possibly in the cylinder itself as my car burns a fair bit of oil.

[mattchaps]

What are people's thoughts on a failed/failing DV?

Am I chasing my own tail? Should I just wait until I can get it scanned?

[MAT ED30]

Sounds like a dodgy dv. You could pop it off the car and check it easy enough if you have the tools,or just replace it and then you know it's 100% done. If you can get it scanned it makes guessing easier

[martziniuk]

What are people's thoughts on a failed/failing DV?

Am I chasing my own tail? Should I just wait until I can get it scanned?

Very much doubt it as it works fine when warm.

[jhono]

got a very similar problem,changed just about every thing,i have free access to vag com as my son is the sales manager at our local seat garage,and every time it points to intermittant misfire,got fed up looking so just got on with it

[mattchaps]

got a very similar problem,changed just about every thing,i have free access to vag com as my son is the sales manager at our local seat garage,and every time it points to intermittant misfire,got fed up looking so just got on with it

If it's not a hardware fault, have you thought about running a trial remap to see if that improves things?

I don't think I'll keep the car if I can't solve the problem, it frustrates me every day!

[LouCyffer]

Matt, is your car manual or DSG?

DSG gearboxes will benefit from a software reset as they 'learn' your driving style. Obviously a second hand one will have the previous owner's learned. Makes a hell of a difference, their's a sticky on how to do it with VCDS in the appropriate area.

If you're in a manual, dunno!

[Boothy]

Similar to the issue I have just had which turned out to be the low pressure fuel sensor for about £40.00 + fitting. Mine didn't resolve when the engine was warm either but what you describe is the same problem.
 When I was having the work done thought the technician showed me an old low pressure fuel pump and what I would describe as a mesh filter around it. The filter was clogged and he said he was getting a few lately with issues like yours/mine and it was caused by this mesh being blocked. He had never had one on a GTI though but may be worth considering if you could get the pump out?
 The DV failure to me felt more like it was flat rather than a hesitation  plus it went better under light loads than heavy, presumably because the higher pressure was opening the holes in it more.

Getting in on the computer is the way to go mate. Even if it you a don't pin point the issue it should help point you in the right direction.