Not boosting correctly

[ze12o]

I have a ka-t stock motor with a gt35r. Problem I'm having is sometimes the car will not boost or will boost very slow (6k 5psi) and never will hit full boost. I'm running a draw through maf and no hesitation when it doesn't boost. Turbo is fine spins freely and little to no shaft play. When the car feels like boosting it will pull hard and hits full boost (10lbs) before 4k. I hear no audiable exhaust leaks either.

Thanks in advance.

[Edwin562]

Have you checked for a boost leak?

[hotlavaflow]

^^^ What he said. Check your cooler piping and vacuum lines

[future]

Waste gate? Bov?

And also why a 35r and boosting 10lbs? Talk about a waste

[ze12o]

Haven't checked in awhile but this has been happening on and off for a while last time I checked it was holding 20lbs fine.

[240sxrb25]

how close is the maf to the turbo, it is very important that its not too close.

[highlifein909]

stock ka motor running 10-20psi??

[240sxrb25]

a boost leak test holds 20psi is what he means i think

his post says 10lbs (full boost)

but you probably didnt read it all

[ze12o]

how close is the maf to the turbo, it is very important that its not too close.

It's far enough. The car doesn't stumble. Car's been daily driving for over a year.

a boost leak test holds 20psi is what he means i think

his post says 10lbs (full boost)

but you probably didnt read it all

Yup. I would love to see what it would make at 20lbs but I never pushed it past 11lbs.

Any other ideas?

Going to recheck for boost leaks tomorrow at the shop.

[godzillarb]

Wastegate leaking/stuck open?

[ze12o]

Don't hear any leaks or feel any air from dump tube

[godzillarb]

Have you tried disconnecting the vacuum line and driving it? Obviously, keeping an eye on the boost gauge.

[bunny13]

stock ka motor running 10-20psi??

This.....is not out of the ordinary

[ze12o]

BUMP still having this issue from time to time. Any ideas?

[di-devol]

So it was boosting fine, and it just started happening?

Timing ok? Our ka-t did this when first started, dist was off a tooth.

[ze12o]

It's on and off I haven't touch in a long time. Would it be possible for it to jump tooth? It's boosting fine for the past two days.