car stutters

[avaien]

Somtimes when on boost or not when I let off the throttle the car bucks back and forth a couple of times. I recently installed a greddy profec b 2 on my car and it started to happen after the install. What I think it is has to do with the hose going from the control box to the wastegate because the tube they gave me does not fit it snuggly and I can pull it off pretty easy. Any other ideas or thoughts on how to fix this?

 

[UNDR PSI]

Boost will cause that line to expand. The expanding line could cause a boost leak where it connects to the wastegate and the controller. Try getting some different line, or some clams and see if that helps. Go from there, and see what happens.

 

[avaien]

will a different size tubing effect the way the boost controller works? also the tube connects well to the boost controller

 

[UNDR PSI]

different size tubing should be fine, my recomendation would be to get stronger line, or clamp it down.

 

[avaien]

I switched the tubing and made sure they were all clamped down but when I get on boost and then just let off the throttle the car still bucks. I feels like when you don't let out the clutch properly. Could this be a slipping clutch? Also with the smaller tube I needed to udjust the boost contorller to 40% instead of the 25% it was at to get the same boost. Is this bad for anything?

 

[UNDR PSI]

sounds like a boost/ vac leak. Might have bumped something when doing the install....check the vac and do a boost leak test.

Boost leak tester

 

[avaien]

When out checking my connections I noticed I mounted the mechanical boost controler piece on the head. Do you think when I let of the throttle the motor rocks enough to cause controler to stutter?

 

[UNDR PSI]

could....move it see what it does

 

[tsunari]

I had the same problem some time ago . . . if I let off the gas slowly, she would buck . . . did an intake pressure test and found quite a few leaks. Biggest one was the brake booster hose.