Ok I have an issue with my max. It is a 1985, 2.0L 2 wheel drive. My problem is the truck runs fine at low speeds (below 55 MPH), but when I get above 55MPH on the freeway it starts stuttering, loss of power and speed, and sounds like it is backfiring. I get off the freeway (under 50MPH) and she runs like a dream.

I've replace the fuel pump (about 3 months ago), fuel filter, distributor cap and rotor, plugs and wires, and air filter (all today). Still won't go above 55MPH.

What am I missing. I also insured that the distributor is tight and not moving (saw this on YouTube)?? Hopefully someone here has suggestions please.

Thanks in advance for any help you might have