Judering. Hesitant acceleration

[Martingdavies1985]

So few weeks about my gt turbo started juddering at low revs but fine once going would occasionally do it when going around roundabouts aswell, now a new problem has arisen when pulling off the engine seems laggy under 3k then above that it hurtles forward with a slight spurt of life. I'm thinking map sensor is on way out, anyone experienced any similar symptoms?

[aleximport25]

My old external wastegate was really lumpy under boost but fine when in her stride, swapped it out and she's smooth as now. Possibly weak actuator or ewg

[Martingdavies1985]

It feels electrical mate, think a trip to td next week may be in order tbh

[Martingdavies1985]

Would a cracked manifold cause problems?

[richardc9052]

Change the distributor. sometimes the cam sensor in them fail.
You can keep your cap and rotor, its the main unit that needs changing if it is. Best to try one off another gt to test first.

[Martingdavies1985]

I've just found two massive cracks on the exhaust mani could this cause it to run bad & can I cause problems like jerking etc?

[richardc9052]

No. It would cause lag and bad MPG but not what you are describing

[Martingdavies1985]

I've got a funny feeling it's map sensor for some reason not sure why, is there any way tuning developments would be able to find out on a dyno?

Or is it simply a case of trying loads of different things? Hasn't long had ignition overhaul at td see

[sosolid]

lambda sensor. same problem i had. check it out

[richardc9052]

ignition overhaul would not have included main distributor unit..

[gibby1980]

Unplug your TPS and test drive the car. Classic signs of a bad TPS imo.

[adzy]

Change your spark plugs? I has similar issues, usually happened at low revs when the car was just warming up. Changed back to copper plugs and it hasn't happened since so I'm hoping that was the cause.

[ChaseWheatley]

My car is doing the exact same thing now it has new plugs, leads, cap still have not worked out what's going on