My 1992 chevy 2500 4x4 with a 5.7 L motor won't start. There is fuel at the motor but no spark. I have changed the dist cap, rotor, ignition mod, and the coil the plugs and wires are only 1 yr old. I had the main computer changed about 6 months ago with a reman. The viechel has about 140,000 miles on it it is my wood cutting and hauling truck, so bieng winter in Wis I am getting very frustrated with it:mad:mad: