Wont start, no spark anywhere

Check the spark, remove the fuse to the fuel pump and remove one of the spark plugs. Connect the plug to its lead and position it well away from the engine against the truck frame (do not hold it) and turn the engine over, check the spark. If no spark it most probably a faulty coil. Check the impedance of the spark plug leads and replace any that are much higher than the rest. My guess is that you have spark but no fuel, What?... OK this is what I think is wrong. Your pump is fine when at position 2 on the ignition switch however when you switch to position three to fire the engine the power to the fuel pump is momentarily disconnected. A leaking fuel pressure regulator or injector would drop the pressure in the fuel line and at the same time flood the engine making it impossible to start. Once you start the engine with ether the ignition is back to position 2 and the pump can make good any loss in pressure but because the intake mix is rich this will cause the engine to run rich too. A good fuel system is capable of delivering 40 - 50PSI of fuel pressure and when switched off up to 90% of this pressure should be maintained for about 5 minutes, if it cannot check out the fuel pressure regulator and injectors. The fuel pipe should be capable of filling a pint pot in about 15 seconds, if it cannot check out the fuel filter is clogged.
Hope the above gives you some pointers