boosting problems

forst off I have a 1990 laser RS turbo with 3" exhaust, hks bov, a k&n filter, boost, oil pressure, A/F gauges. i just bought it a week ago. when i was getting it the man i bought it off of told me it runs but it has some problems. needless to say i got it anyhow.

well the problem is it drives smoothly up till the point it hits 0 on the autometer boost gauge (the point it starts to boost) then it starts to sputter and miss, at which point boost all of the sudden kicks in at full (10 psi) and the car takes off like hell. it doesn't do this however when its cold only after it warms up. one other thing is that the car only runs with the mass air unpluged, i don't get it lol. when i try to plug the mas in, the car just dies. any help would be awsome and if u have any questions about anyting related just ask, thx.

plug it in and reset the ECU. change the spark plugs.

did that 3 or 4 times

Could be a bad MAS. With it plugged in the ECU will believe anything it says. With nothing plugged in the ECU will realize this and go to some back up maps. Just good enough to run, but not right. If you have a logger check what the Baro and Intake Air Temp values are. Odds are one is hosed. Both sensors are part of the MAS. If you can borrow another MAS, try that.

thats what i was thinking. B/C when the car is cold or just running cooler it boosts fine. thanks for the help