I have a 1989 f150 with a 302 in it. I just got new spark plugs. Wires. Rotor cap. Distributor and regulator. I can start it up just fine but within a few second it will drop to 150rpms and stay there then I can press the throttle to the floor and get nothing if I pump it it will jump and when I get it passed 1200 rpms it will skip bad. I tried driving it down the driveway and after 1200 its cuts power then gains it like there is a wire problem. Any idea.

My mechanic said my wires are all green. Idk if he means wiring harness or like a thousand dollars worth of rewiring the whole truck

How is the fuel pressure?

Perfect and all the injectors work. Pumps are good just won't stay running.

Check the harness where it plugs into the engine harness on the left side above the frame.If these re corroded cut the plug ins off and solder each wire back together with heat shrink too. Also check the small black ground wire at the battery with the connector for corrosion. This is the PCM ground.

Ya my mechanic said all my wires green and corroded

These wires I stated are the main wires for it to run.