could it be my CAS

[skyyred]

alright i have a s13 sr20det...every time i gun it, it'll speed up for about 2, to 3 seconds then it will start bucking it idles fine and drives smoth at normal speeds it doesnt buck if i speed up gradually it does it from 90 100% throttlei tried adjusting the CAS and by just moving it a hair changes how long i can gun it before i starts bucking... at one point it ALMOST whent away.....

checked and changed- spark plug- fuel filter- fuel pump pressures normaly- cat- TPS new- maf was checked by a mechanic friend- ground- timing is right even the cas

is there a way i can check it..if its telling the ecu the right thing or can it be my ecu

[skyyred]

anyone have some knowledge they can share with me

[Morgs]

what is ur timing set to? maybe try advancing it 1 or 2 degrees see if thathelps?

[skyyred]

thanksdoes anyone else have a input

[skyyred]

bump

[RinseCycle]

Hey man

I know you said you had a mech friend check your MAF... have you tried a known good MAF? we had that same problem on our RB25 install and a SR20 install - both turned out to be maf related problems.

Has this always been an issue? if not how long ago did it start, and did anything change before it started happening?

[180fan]

possible ecu but since it also seems to be throttle dependent, what was the tps calibrated to?

if it were weirder or hade a 2500rpm limit I'd point out the mafs

if it were the cas, your problem would be more consistent rather than after it's moved.

[nuts510]

check all your intake hoses you are looking for a leak that is occurring when your engine starts to boost you can try blowing air into the intake right at the Turbo and see if you can hear it any air leaks I actually use a regulator so I don't get too much pressure, I have seen more than one car start jerking like crazy when you start getting full boost because of their leaks. This a jerking sensation pretty violent? Does it get worse as you build a more boost? If so check for leaks