Mitsubishi Repair: Loose of power, mass air sensor, mitsubishi mirage

Question
QUESTION: I have a 1996 Mitsubishi Mirage 1.5 (4G15 engine) with 150000 miles.  I had a bad smoke problem and sudden loose of power so I completely rebuilded the engine. Machined the cylinder head, replaced piston rings, main and conecting rod bearings, timing belt, crank sensor, distributor (entire ignition), and a few other odds and ends.  The engine was in very good condition internaly (no ridge on cilinders), but the cilinder head was a little warped, machine shop did the works on it. The car had been sitting for about 2 years till I could get it fixed.  Now, Im experiencing hasitation when the engine is reved up.  It idles prefectly and if I rev it up slowly, it reves nicely, but if I try to accelerate hard, it looses power to the point of dieing unless I let it idle again. There is no smoke at all.  I pluged the fuel regulator hose that returns to the tank to see if the regulator was bad, but it continues with the problem.  I pluged the fuel line coming in to the injectors with my finger and had someone crank the engine and fuel preasure seams good.  I know its not like using a fuel preasure gauge but, oh well... I have no idea what alse to check.  Do you have any sugestions?

ANSWER: Edgar,
This issue can be cause by inadequate fuel supply or lack of air flow.  Check your air filter and mass air sensor.  If there is lack of air flow, your engine can stall if the computer detects too rich of a mixture.  The same can happen if there is a lack of fuel.  Your car's computer is more likely to stall out when there is a lack of fuel because detention can occur, which could damage the internals in your engine.  You can try cleaning out the fuel rail and injects to be sure.  Also ensure the fuel pump is operating within tolerance.  A pressure gauge would be best to check this.
Good luck!

---------- FOLLOW-UP ----------

QUESTION: I checked fuel preasure and its within tolerance. Also cleaned injectors and fuel rail, changed fuel filter. so whats next?

Answer
Edger,
Test out your mass air sensor.  Sensors such as the idle air temperature, and barometric pressure sensor can all be test to make sure they are within tolerance.  In addition to that, check your EGR valve, PCV valve, and your throttle position sensor.  If all are good, the next thing to check would be your car's computer.  You can check for any damage to the circuit board.
Good luck!