Truck won't crank need help

[KeariDonald]

I crank my truck it runs fine. I will go to a store come out and it won't crank. Come back a couple hours later and it will crank right up. Sometimes I will be going down the road and it will quit and won't start for a couple hours. I had it hooked up to a computer and it says it is missing on all eight cylinders (it has done this since I bought it. We have replaced everything but the crank shaft) and O2 Sensor was bad, which we replaced. What could be wrong with it. 96 Dodge ram 1500 2 drive with a 318

[carriedi]

ok, since you say it won't crank, does everything else still work? dash gauges, radio, headlights, everything except the engine? or does everything stop too? When it won't crank are you able to check the starter solenoid to see if you are getting power to the solenoid from the ignition switch?

[KeariDonald]

It acts like it just isn't gas. I sprayed starter fluid and Crunk one time but as soon as i stop sprain it goes dead. When I turn the key I can hear the fuel pump come on.

[carriedi]

ok, that's a different problem. "no crank" means the starter is not cranking the motor over. What you have is engines cranks, no start. Since you have already figured out that it have the spark needed to run you have to find out what's up with the fuel side.

don't use too much starting fluid. it's bad for the engine. the fuel pump turns on (as you can hear by the noise the motor makes but are you getting enough fuel pressure. Fuel pressure on this engine should be 44 to 54 psi. lower fuel pressure may lead to a no start condition.

If fuel pressure is within spec you need to check for injector pulse. each fuel injector has two wires going to it. One is for power and the other is for the ground signal from the computer. while cranking the engine see if you have injector pulse. You can check for pulse by unplugging one of the injectors and running a light bulb or a test light between the two terminals in the injector harness. as the engine cranks over the light should blink on and off telling you if you have battery voltage completing the circuit.

have you scanned the computer to see if you have any codes like for the cam sensor