Apparently my car is running on 3 cyilinders when at around 1500-1800rpm.... I've never noticed anything but then I'm a numpty and I trust a mechanic more. Any vibes I always put down to being the flywheel.

So, the question is why would it be running on 4 cylinders fine at tickover + a bit, and over 2000rpm it's also fine. Why might it be a bit lumpy at this particular rev range? Car in itself is going fine but having donated it to my mechanic mate for the best part of this week, he found the hesitation/lumpiness at 1500-1800rpm really infuriating.

Looking forward to suggestions. One for me is perhaps the cam isn't exactly the right profile? Or perhaps the car needs tuning again to remove this "stutter", something not there when it was tuned on my old running gear.

PS: vagcom brings up nothing wrong.

probably need the map tweaking in that particular rev range

probably need the map tweaking in that particular rev range

Experienced similar issues in any of the galaxy range that run this same engine? (engine type at least)

What have you messed with recently ? You know which cylinder?. Don't think it's compression as that unlikely it wouldn just effect a specific rev range

If it was me I would be tracing the fault back from the injector, see what kind of signal it's getting and work your way back, although to do this correctly you may need a spec anny or at very least a really decent multimeter.

Experienced similar issues in any of the galaxy range that run this same engine? (engine type at least)

nope , might be just specific to your map , or one of the injectors has some issues

I can't put it down to an injector acting odd as I had all 4 bench tested prior to fitting, and all were pushing more or less identical fuel loads under the same pressures.

Good to know it's likely to be the mapping as that can easily be changed.

Mine does it too Jase. You on the big nozzles now?

Ask Mr Washbrook, and he will tell you why it does it

I can't put it down to an injector acting odd as I had all 4 bench tested prior to fitting, and all were pushing more or less identical fuel loads under the same pressures.

Good to know it's likely to be the mapping as that can easily be changed.

When were they fitted?

I know why too,

Share it with us then you two

Apprently is something to do with the injectors. Its the reason I havent gone for big injectors, they are just so damn hard to set up.

It's basically the injectors are running at the wrong cycle. Apparenly, very hard to map out, you need to have a certain type of ECU so the injector scaling can be sorted to get rid of the issues. I've almost learnt to drive around it now, keeping it always on boost to some degree.

AFAIK I've never had this prob - first time I hear of it too....