I recently bought my son a 1993 940 2.3 4 cylinder rwd Volvo. I am a small engine mechanic by trade and a descent shade tree machanic, but i dont claim to know everything. Thats why i need your help. Heres my problem.

The car sat for a long time (maybe two years). The car would'nt start when i initialy got it home. It needed a fuel pump, which i replace, remove and cleaned the fuel tank (lots of water in it), replaced the fuel filter and cleaned the fuel lines. I can get the car to start by spraying carb cleaner in the throttle body about 10 to twlve times before it will idle on its own, as it warms up it will idle a little better, but when i turn the throttle control by hand i can here some hissing by the throttle body (like a vacum leak), but i cant find any leak. the car struggles to power up? I'm thinking maybe its a sensor of some sort that might be bad. Any ideas out there? Thanks!