Okay, so my 94 Dodge Ram is having problems starting up. We replaced the starter, alternator, fuel pump, and tons of other stuff. The truck starts up fine 50% of the time, and the other 50, it won't. It sounds the engine wants to starts, makes a stroke sound but won't turn on. We bought a special spray that if we spray it inside the intake manifold, it'll spray a highly flammable liquid and with that it'll start if we keep trying.

Without that, which we found in Autozone, then the truck will just keep trying to start but won't do anything.

 

sounds like you are not getting enough fuel to the injectors if you have to use starting fluid. i would put a gauge on your fuel rail and monitor the fuel pressure to see if it is bleeding off when you shut the truck off.