Has anyone had this happen , I was in 4th at about 6k rpm going climbing through revs when it cut power and felt like I was bumped from behind I let off it seems ok but I dint take it above 6k revs again just scared me a bit as it's never happened before has anyone had similar thing happen car is a 03 jdm sti

 

Check your vac / boost pipes as they may have gone brittle and cracked due to the cold weather we are having which can result in the symptom you describe

 

As Zany says most common for split pipes to cause boost/fuel cut.
Or you could be suffering Det.
Mapped? Mods? And what fuel you using?

 

Yer I did change boost hoses to samco its hard to see if they popped of or not , but what ossett2k2 said about det it's had same fuel in for about 5 weeks ( v power ) would that make difference mods are
Cone filter
3 inch cat back
Walbro 255
Grade 7 plugs
With custom map

 

Were you low on fue when it happenedl and when you changed the fuel pump did you use the original filter sock or the shorter replacement that comes with the kit?

 

Can't remember now think used new one but think you got it Shane it was about quarter maybe little less

 

Nah fuel takes a lot longer than 5 weeks to go off.
Could be lack of fuel but starvation generally happens on hard cornering.

 

Pushing 6k+ rpm in 4th it's taking the engine to the highest load scale especially if on an incline,is it a recent remap and was it dyno or road mapped?

 

Was road mapped was about a year ago it's been fine , I think it's lack of fuel

 

Cool,fill it up and see how you get on

 

Yer will do it was just the bump from behind that scared me

 

Yup would be pretty violent cutting at that speed.

 

Ive got the small sock on my walbro aswell installed by previous owner and will only have the symptom mentioned if ran on red and try to boost
only ever done it once so I keep mine over 1/4 all the time
Until I can get enough funds for a rcm item this year and replace with genuine sock which I have had since last year

 

Never experienced it myself, just read on other posts in the past and threw it out there as a possibility. Always worth trying the cheap fixes first.

 

Or cold weather = slight overboost and hit the fuel cut!

 

Should be mapped with headroom for baro pressure increase due to cold weather.

 

It SHOULD be, but doesn't mean that it was! Lots of threads where they had to go back for a tweak due to hitting fuel cut. How many mappers check cold starts, or map across the load scale, let alone all the other combinations of factors that can affect how the car runs?!!

A violent jolt is likely fuel cut or starvation, because you're not suddenly going to loose spark on all 4 cylinders due to coil pack failure, spark plugs etc.

Other possibilities are failing crank/cam sensor but unlikely imho.

 

^^^agree
This was my point,especially if road mapped,hard to cover all conditions,especially at 6k+rpm in 4th gear I doubt many mappers push this on public roads.
Dyno+road map is ideal or road mapped over more than one session.

 

Had similar. Felt like a violent shove. Diagnosed as a fuel cut, map tweak sorted it.

good luck