Power loss, judder under acceleration

[JonnyB_UK]

Ok so driving on the m25 today after coming out of heavy traffic I put my foot down and there was a dramatic loss of power and juddering. There was no excess smoke or weird noises it was just pike the car didn't want to go! The turbo spools up fine and then the power dies off. I'm dreading a massive bill after reading about scv's! Any ideas guys?

[signum_rob]

Engine?

[JonnyB_UK]

Ha! I've been advised it could be the MAF....

[nutron]

If it is in limp mode then there should be a code. If the turbo was dying, there is usually a whining noise and/or excessive smoking due to oil loss into the exhaust/engine. MAF or MAP sensors failing are quite possible.

[JonnyB_UK]

There is no smoke now it used to chuck out a bit under hard acceleration but I get the impression that's fairly normal. It's booked in for a diagnostic tomorrow but there are no fault lights showing...

[mat_splat]

I have a similar problem with my Z18XER. It got progressively worse until the coil pack went and lost a cylinder. New pack seems to have sorted it but it's comming back... Only when the engine is under load and not just revving. I am at about of a loss now.

[JonnyB_UK]

Well I'll keep you posted! Hoping its not SCV or injector related as I've heard horror stories about the bills for fixing them!

[JonnyB_UK]

The stealers reckon its something mechanical so first port of call is a fuel treatment...

[mat_splat]

I have tried that on my petrol one and no change, does the Z18XER have an SCV?

[JonnyB_UK]

No idea but I got the impression its a diesel part