The car a 87 GXL;
This is the third motor put in this car and it sorted had the same problem with the last motor.
The motor;
The motor is a factory rebuilt that came out of a 86 and was then put into a 88 GXL, it ran great tell the car was totaled
The problem;
The car idled great and ran fine as long as you didn't give it full throttle. At fist we thought it was the 3800 rpm hesitation because it seamed to die out at 3800. we tried all the fixes for that and nothing worked. After spending hours searching this web site and others we still could not figure it out. Then I started thinking, the car is a 87, the motor and wiring is out of the 88, 88's don't have a resistor pack, so if we took the resistor pack out and wired the wires all together the car should run right.
By doing this the car in deed ran right, we now have full power with out any hesitations.
I thought that I would share this with others that may experience the same problems

 

Good info!