Hi, I have a 1986.5 Nissan Hardbody pickup (D21) with the Z24 engine. While sitting in neutral, you can give the truck gas, and accelleration is normal, and the powerband is there, but while on the road driving, in any gear if you accellerate, and put the engine under a load, it will cutout, and bog down. All power is lost. You can't even pass someone if your only going 40 MPH. As long as you down shift though, and slowly increase you RPM's you can get back to speed, and the truck preforms somewhat normal. I have replaced the wires, plugs, fuel filter, cap, rotor, injectors were cleaned, and tested fine, fuel pump seems to be operating normally, and does not make any funny sounds. I am at a loss. A buddy of mine said it might be the coils, or the ignition controller. What do you think? Could it be that or maybe something else? What would you try?