Boost cut/limiting?????

[flight doc89]

I tried to search boost cut but cut is too short of a word to include in the search...

I have an HKS manual boost controller installed on my car, and we decided to turn the boost up tonight.
After turning up the boost with the controller the car is spooling to 10-11psi and then seems like its getting limited or something and dropping back down around 7-8psi as if running stock boost.
Almost like its spiking and if we keep turing it up its just gonna hit fuel cut when it spikes up.

Any ideas?

Thanks

EDIT: it isnt just the guage that drops; we feel and hear the turbo spool up and drop back suddenly.

 

[1988SupraDreams]

What other mods do you have? And if a word is too short add a * to the end of it.

 

[Bishop92t]

Boost leak, improperly setup boost controller, possibly something else weird check engine error codes.

 

[flight doc89]

3" exhaust, turbo back (no cats)
TurboXS BOV
K&N FIPK
stock fuel system
EGR blocked off

if i think of anything else major, i'll list it.

The MBC was installed by a local race shop. they said that the stock fuel cut was 14.7 psi, which sounds about right, because the few times that we boosted it that high, we hit fuel cut. right now, i have it set so that it maxes out at 12, but once you rise above 10 or so, a half second later it drops back to stock. it isnt fuel cut; it keeps boosting and making good power, but i can physically hear and feel the boost drop back down.

EDIT: also, the check engine light is off. it came on for a few seconds when we hit fuel cut, but it doesnt stay on. it does NOT come on when the boost backs off.

 

[Bishop92t]

You need to actually check the engine codes. The light only stays on when its considered a more important problem. Lesser problems get stored but do not trip the light.

 

[madseacow]

test for boost leaks. do nothing else first.

 

[MaxBoostedSupra]

it could be your BOV, my friend had an RFL and it would leak and do the same thing around 11 or 12 psi