jerky above 2/3rds boost, fuel problem?

[jongrier]

95 gsx, 90% stock. only have a 16g, stainless header, and a mas adapter for round airfilter. basically whats happening is everything works great untill the boost gets up over 2/3rds on the stock boost gage... but it is inconsitent, for example if i build the boost sy i can get it up to full no problem, but if i romp on it, it gets to the 2/3rds line and starts jerking... like the bov is poping up or somthing. i recently put and aftermarket bov with an adapter for stock intake tubing, cranked the bov all the way down and it still did the same thing. running the stock plastic bov again now. wondering if maybe it coyuld be a fuel management problem... perhaps the stock fuel pump cant keep up with the bigger turbo... i just want some professional confirmation on that before i spend the money... i work on cars alot but this is my first dealing with forced induction... thanks for the help. sorry if this is a stupid question! i really did read around to try and help myself... just got kinda frustrated afterall this has been going on for a while i just never had the funds to take care of...

 

[cjridert1]

The car is jerking and boost holds or is the boost fluctuating too? What psi are you running?

 

[n1clipse0101]

Yea, sounds like a boost leak to me. Are you holding steady at boost, and what kind of vacuum line are you using for your boost gauge? Got a boost leak tester?

 

[jongrier]

actually thats a duh question thanks... i didnt think to look to see if the bost was holding... actually it will continue to build, with the same jerkyness that i feel in the car, i am running what ever stock psi is, with more airflow though becuase of the 16g. and no i dont have a boost leak tester... how much do they usually run or where should i get one from?

 

[snowborder714]

IC Pipe Tester

 

[n1clipse0101]

Hold up, don't go buying any pre-made tester. Go to the Vfaq section and type boost leak tester. I just made my own for 5bucks just by going to Home Depot. It's incredibly easy and cheap. Sorry just noticed snowbaorder714's post my bad, but yeah thats exactly what im talking about. Hey Brian, when are we hitting the slopes, man i cant wait for this season!

 

[NightRider97]

The easiest thing you could do is check your spark plugs. I have had this issue from time to time in my car, same thing, anything over 2/3 throttle and it would pop and give you shaken baby syndrome. So far, every time its been excessively gaped plugs.

 

[big_d]

untill the boost gets up over 2/3rds on the stock boost gage.

...I wouldn't trust anything that stock boost gauge says. I would buy an aftermarket boost gauge, perform a boost leak test, and unhook my wastegate actuator until then. You also have to realize how easily these 16g's can creep, and how hard it might be to keep boost in control as to not overrun your fuel pump. I would definitely do plugs and wires while your at it. It's cheap insurance down the road.

 

[MrBoxx]

Before you go romping on your car again, properly install a quality boost gauge. The stock gauge cannot tell you whether you're maxing out at 12psi or 20psi. I'm willing to bet that A: your 16g is creeping/spiking, B: You're running WAY more boost than your fuel system can handle, and C: That you have boost leaks, which may be leading to fuel cut.

Also, as a reminder, I will ask everyone to please use proper punctuation, spelling, capitalization, and grammar in their posts. Walls of text are not fun to sift through for information.