Car Jerking on Boost
 

Hey guys.
My MY99 WRX is due for a service but just in the last few days it has been revving very jerky when it comes on boost. Im a bit worried so I wont be driving it until my mechanic gets back from holidays and can look at it.

Any ideas? Could it be misfiring? Bad plugs? Coil pack? Vacuum leak?

Im not hugely tech savvy when it comes to cars so any suggestions would be great :)

if its just starting doing it overnight, its more than likely poo fuel.
if its been slowly getting worse it could be a number of things and your mechanic is the way to go.

spark breakdown

Dont rule out the good ol craptastic my99/00 AFMs.

[QUOTE]Dont rule out the good ol craptastic my99/00 AFMs.[/QUOTE]

x2 I had the same problem and it was the AFM.

I was told by several mechanics while waiting to get the car to Subaru that the problem was most likely to be a dodgy fuel pump / fuel filter / spark plug / ignition leads / vacuum leak / boost leak.... subaru replaced the AFM and all was well.

Yeah sounds like it could be many things. Specially a vacuum leak as its happening when it comes on boost. AFM shouldnt be ruled out and yes, crappy fuel could be a possiobility making for dodgy combustion. So many things it could be, good luck finding it!

Not wearing thongs when it happens are you? Cause sometimes that can happen when the heal gets a bit caught on the floormat ey. when it hits the full boost.

[QUOTE=atz 242]Not wearing thongs when it happens are you? Cause sometimes that can happen when the heal gets a bit caught on the floormat ey. when it hits the full boost.[/QUOTE]

he could be wearing a thorong when it happens. or is that a throng? or a sorong? or a sarang? oh i dont bloody know but he could be wearing one

Air Flow Meter +1
does it also stutter when you are trying to cruise?

Actually it does stutter sometimes when I'm cruising. Only started happening recently too in the last week or so.