Stock boost gauge question, seached. please read!

[3kgt2dsm]

Hey guys, i have a 91 awd 5spd TSI
YES i have an aftermarket boost gauge, yes its hooked up properly.

my question is, as of lately my stupid stock boost gauge is acting really wierd, like at idle it will sit at +7 boost, and under load and boost it goes PAST the 14.

the kid i got the car from says he had the caps replaced, and i see its a 92 ecu, so im not sure whats going on as i have not looked at it.

the SPI boost gauge i have reads 15lbs rock steady and i know the turbo is working, but sometimes i feel as if there is no power, and other times in different gears, the car pulls like a train.

mods are as follows, ported 2g o2 housing, boost controller, spi boost gauge, Monster Performance Fuel pump rewire kit, balance shafts removed, and a K&n filter.

i know the gauge is useless for monitoring boost, but its not acting right at all so its telling me something is wrong. i wonder what it could be? any ideas?
thanks for your time guys, this place rules.

 

[ADrewzki]

Someone correct me if I'm grossly wrong but I think the stock boost gauge is electronically driven. Your ECU computes how much boost it thinks you're seeing by using the amount of airflow through the engine and some preprogrammed algorithm. So on that note, I would say that either your ecu is getting the wrong information about the amount of air being sucked in (MAS problem) or your ecu is bugging out. Hope that gives you a good place to start.