Lost top end power

[sn95gt19]

fuel pump could be the prob. thats why you should check the fuel pressure, and no i dont think you can check it just by revving it. i think the motor has to be under load. the mass air elements can go bad, the little elements in the mass air are heated, and when the air passes by it, it cools the sensor, and sends a voltage signal to the computer. the plug on the harness is grey and is square, you have to unplug it, inorder to check your timing. otherwise it will tellyou the timing is at like 25*. i think its right next to the distributor on the fox bodies, not sure though. one more thing about mass air sensors, when they go bad you USUALLY only notice it at WOT, it will usually bog down and fall on its face when you floor it, but runs normal under part throttle conditions. i would check your timing, then your fuel pressure first though.