Mitsubishi Repair: 1995 mits eclipse gsx, air fuel ratio, eclipse gsx

Question
when i am driving my car and i step on it and it hits like 4000 rpm's it falls on its face. it continues to miss until it switches gears. has a rough idle and when u hit the gas it stalls out as the rpm's fall to nothing. When you are not driving it and you rev it up to 4000 rpms no problems only when driving. Already had timing belt changes. Have a leak by the turbo and where the exust manifold meet think this could be my problem. Also changes all fuel injectors and added on a hallamnn manual boost contol.Please help have no idea i just bought the car. thank you

Answer
Mike,
The car's computer will cut the fuel supply if the air/fuel ratio falls outside the tolerate boundary.  Any air leak or unmeasured air entering the system can make the car think the fuel ratio is wrong, which can immediately cut down the fuel supply and automatically retard the ignition timing.  Too much air detected can cause detonation inside the engine, essentially ruining the internal engine components.  So the engine may be stalling to save itself.  Check for air leaks, and patch up the one you've identified at the turbo.  Also dialing back your manual boost control so the pressure is back to stock.
Good luck!