Acceleration Hesitation? Ideas?

[Polyol]

All,

My problem is an acceleration hesitation that I only notice in 2nd gear. It never happens when im rowing through gears though. Only when accelerating normally (very little gas) through 1st, then shift to 2nd accelerating normally....then if I hit the gas (still in 2nd gear) my pressure goes up to 17lbs (even though my MBC is set to 15lbs) but there seems to be no power...almost as if naturally aspired :thumbdown . If I pump the gas in gear the hesitation goes away and my normal 15psi is reached...and good acceleration occurs.

Is my wastegate malfunctioning? That was my first guess. No boost leak for sure because I pressure checked it to 20lbs. Let me know what you think? Thanks...

Ohh...my mods are UICP+J-pipe, KN intake, MBC @ 15lbs, 1g BOV, BPR7's, and a 2.5" test pipe; however, this problem occurred before I got the BPR7's and the test pipe (so its not boost creep).

 

[rsr93]

the no power part sounds like phantom knock. your timing is gettin pulled( im pretty sure ) from the way you describe it. on and off the gas then back on it phantom knock will go away most times in the low rpm range.

dunno if alot of phantom knock happens with 2g cars but im sure they get their fair share.

but need more info on the boost part.
does the boost just spike to 17 and then taper back to 15 or does it stay at 17?
and what gear pull did you set your contoler in?
also does it just happen when you have the hesitation problem?

 

[Polyol]

the no power part sounds like phantom knock. your timing is gettin pulled( im pretty sure ) from the way you describe it. on and off the gas then back on it phantom knock will go away most times in the low rpm range.

dunno if alot of phantom knock happens with 2g cars but im sure they get their fair share.

but need more info on the boost part.
does the boost just spike to 17 and then taper back to 15 or does it stay at 17?
and what gear pull did you set your contoler in?
also does it just happen when you have the hesitation problem?

does the boost just spike to 17 and then taper back to 15 or does it stay at 17?

No, it stays at 17lbs till I let up.

and what gear pull did you set your contoler in?

Im not sure...I just did my pulls till I got it dialed into 15lbs...it usually hold 15psi in all gears (tapering off to redline of course).

also does it just happen when you have the hesitation problem

Yes...however, I see spikes to 17lbs sometimes but it falls off very quickly to 15lbs. When the hesitation occures it goes up to 17lbs and stays at 17lbs...it doesnt fall off at all.

 

[rsr93]

usualy you want to set the boost in a full 3rd gear pull.

looks like your just getting normal boost spike.

no exhaust no dp no portwork.
also some mbc like to spike.
could be a combination of these.
causing the spike.


the hesitaition part is most likely phantom knock in the low rpms like i said earlyer everyone just has to deal with that crap including me i hate it.

hope this helped.

 

[Polyol]

usualy you want to set the boost in a full 3rd gear pull.

looks like your just getting normal boost spike.

no exhaust no dp no portwork.
also some mbc like to spike.
could be a combination of these.
causing the spike.


the hesitaition part is most likely phantom knock in the low rpms like i said earlyer everyone just has to deal with that crap including me i hate it.

hope this helped.

Yah...thanks! The phantom knock will cause a major loss in power huh? Why does phantom knock occur?