Merv

iTrader: (12)

04STi JDM car runs and pulls well,but on lift off and holding say 30mph in fourth the car feels jerky like its missing.Changed maf,lambda and cleaned idle control valve,but still does it.

Any one had this problem before?

Cheers
Merv

cookstar

iTrader: (6)

Have you checked the dump valve?

Merv

iTrader: (12)

Would that make any difference off boost at low revs?

Candan

No CEL, Merv?

Does the whole car buck? Or is it just noticeable to you?

Henrik

iTrader: (5)

Mine certainly feels a lot smoother across the rev range with the OEM dump valve fitted (although I went from FMIC with no dump to STI8 TMIC with OEM dump valve)

Merv

iTrader: (12)

Checked psi3 ecu monitor,no fault codes.

The car doesn't buck,more like a jerk,run on ,jerk run on etc,abit like a missfire,but only on lift off.

Candan

Only on lift off, when pushing the car hard or regular pull away? How about 60 mph at constant RPM? All smooth again?

30mph in 4th gear, is low RPM. How about 50 in 4th? Same thing?

Merv

iTrader: (12)

Yes high revs are good,but as revs drop it starts.Constant 60mph no problem.
50 in 4th is fine but if I lift off and the revs drop it will start to jerk.

TonyBurns

iTrader: (3)

I take it you upgraded your turbo? what other mods were done to the car for that power?
Thing is, these cars should run very smoothly with the twin scroll turbo, it could be a problem with the map if anything has been changed, also does the car have a full decat? that could be mistaken for a misfire.

Tony

Merv

iTrader: (12)

Tony,standard turbo,other mods include RCM induction kit,Forge recirc dump Vv and full decat 3" Miltek.Mapped by Bob Rawl last year and been running great since.
I have switched maps but still the same.

cookstar

iTrader: (6)

Whack the standard DV back on and see what happens, should only take a few minutes.

Merv

iTrader: (12)

Just tried that,still the same.

cookstar

iTrader: (6)

dammit