just put a engine out of a perfectly running metro with bad subframe(imagine that).idles great but backfires and sputters when trying to accel. timing is on point so not that. put new plugs rotor cap and wires inc. coil wire.coil was tested good,pcv new,everything has been tested or switched with running donor im stumped. has to be something that was on car it went into right,since it ran perfect when it was in bad frame car. could the fuel pump or filter be bad but only effect at higher speeds? it doesnt wanna go at all. sounds beautiful when idling. compression in all 3 cylinders was above 175 or 180. please give me advice or im gonna give up and take it to the garage! i never wanna give up and give into the car and admit defeat.donor motor has only 80,000 miles.! please help me out!!!!

If it shudders and misfires under load, it's almost definately a fuel problem. Perhaps the fuel filter is plugged? That could have been what ended the other motor, a lean mixture will tear a motor to shreds.