Studder coming on to Boost

[Ca_Silvia]

I tried searching and just wading through all CA pages because i have seen a topic discuss this before.

In low rpm only <4000rpm when cruising at 0psi the car starts bucking/studdering almost like a misfire but as soon as i lift off or give it more gas its fine. Only at 0psi does it do this.

Only thing changed recently is an upgrade to a SR turbo. Ive checked fuel pressure, clean MAF and changed plugs to 7's (6's before but it was doing the same thing with the 6's and 7's)

Any ideas?

[Ca_Silvia]

On the way to the track tonight i noticed the hesitation starting at 10in/hg right up to 0psi then nothing once in boost. Got to the track upped the fuel pressure to 38 did a few practice runs lapping around, no issues. Got home pulled the plugs they look normal. Im gonna DD it for a few days and keep an eye on the plugs.

[ca18detgabby]

check and make sure each coil pack is sparking..........

rico.......

[240sxbobbis]

sounds like my problem but after i drove it the car completely cut off and wont start dont know whats the deal but im ready to burn the mutha #$%^&% but any ways does anyone know what can be done?

[rico05]

Vac leaks.

[Ca_Silvia]

Oh yeehaw, vac leaks my favorite thing to search for on my car

[Ca_Silvia]

I thought i would update this thread for people who search. I removed the boost solenoid completely, all vacuum lines, even the plug to the unit. Its all good now no studder at all.

[ca18detgabby]

interesting.......... I bet one of those lines had a hair line crack and was funking you over. such a pain in the ***.

[Ca_Silvia]

Some how i doubt it, i boost leak tested up to 20psi and nothing was pissing out. Im guessing that the larger turbo running higher boost was throwing something off in the solenoid. Keep in mind the boost controll solenoid t's of the wastegate line so that might have something to do with when exactly the wastegate opened.

[Rin5]

yeah...who needs stock solenoid anyways right?...jk

by the way ====> Stutter double D's are nice but its wrong

[RS12Turbo]

20psi on a t25g?

[Rin5]

i boosted past psi meters before...on neutral when i was looking for whats wrong with the boost...

i found the int.wastegate vac was ripped and wasnt opening

[Woods Crasher]

I thought i would update this thread for people who search. I removed the boost solenoid completely, all vacuum lines, even the plug to the unit. Its all good now no studder at all.

Those solenoid valves always go bad on older nissans. You get probably get that valve from another car or new at the dealer. they're usually in the 40 - 100 range.