06 wrx throttle hesistation on WOT
 

Hi guys,

Have been searching around and I only seem to find boost/fuel cut as a reason for throttle problems though my problem is a tad weird.

I go to accelerate the car foot fully down (I usually squeeze the pedal down to wot as its fly-by-wire throttle and doesn't respond to sudden movement as well as the older throttle cable/linkage).

As I am doing this the car accelerates extremely slowly in 1st and 2nd (much slower than I am used to) and hesistates/stutters as it rises revs (between 2 and 3k)...at 4k-5k its still accelerating slowly (again, slower than it should be doing this)

I know boost gauges are not accurate by if its any help mine is showing I am hitting my 15psi at around 2.5k

My only guess is either bad batch of fuel or the ecu is in limp mode (not getting any kind of warning/CEL lights)

Car is a 06 wrx, only power mods are a 3" Butler TBE, Walbro Pump and EcuTek tune.

Im boggled and worried
-Shane. :confused:

are you able to log some wot runs ?

I wouldn't know how to do that dave (do you mean actually video it or log it onto a pc?)

Log with a datascan or such?

Nope I would definitely not know how to do that Andrew :(

Umm ... If you can plug in a cable and have a mate with a ECUscanner it takes no time or skills at all. ;)

I see, now a mate with an ECUscanner hahaha, will see how I go.

Im going outside to check out the air-filter (K&N), swapping the oem one back in.

Feels like the throttle is being choked, worth a shot.

Shane, Ive got one, so does Dave, etc. I actually have no idea what ECU variables to diagnose. Anyone on the mech / tech side want to help with variables to log to diagnose problems.

I believe it can log up to 9 engine stats at once.

Since there are no cels, possible cause:

1) AFM --- yup you are checking the filter
2) Spark plugs + coil paks
3) fuel filter
4) vacuum/turbo leak
5) Worn turbine but i doubt it

My 2cents

[QUOTE=xsv4rce;588099]Hi guys,

Have been searching around and I only seem to find boost/fuel cut as a reason for throttle problems though my problem is a tad weird.

I go to accelerate the car foot fully down (I usually squeeze the pedal down to wot as its fly-by-wire throttle and doesn't respond to sudden movement as well as the older throttle cable/linkage).

As I am doing this the car accelerates extremely slowly in 1st and 2nd (much slower than I am used to) and hesistates/stutters as it rises revs (between 2 and 3k)...at 4k-5k its still accelerating slowly (again, slower than it should be doing this)

I know boost gauges are not accurate by if its any help mine is showing I am hitting my 15psi at around 2.5k

My only guess is either bad batch of fuel or the ecu is in limp mode (not getting any kind of warning/CEL lights)

Car is a 06 wrx, only power mods are a 3" Butler TBE, Walbro Pump and EcuTek tune.

Im boggled and worried
-Shane. :confused:[/QUOTE]

Thanks Andrew, if I need it I will be in touch, looking good for now.

Thanks Mao, I put the OEM filter back in, big difference, very very minor stutter, hardly noticeable (I guess the ECU needs to adjust again?), fresh tank of BP98 too while I was at it (filled from quarter up if thats any help).

Dad hinted at the sparkplugs, maybe they need changing (car is due for a 77,500 km service soon, it is currently at 74.5 but I may take it in earlier and get the service done with new plugs + coils if neccessary).

Checked the vaccum lines, everything is secure and where it should be.

Thanks guys, I'll see how we go over the next few days.
-Shane.

PS: Mao I wish it was a worn turbine would be a good excuse for that TD05-20G upgrade haha. :)