99 ram with 5.2 wont start, good fuel pressure on rail, good spark. no engine codes any ideas

Does the rotor turn when you crank it? If you hold the coil wire close to engine ground, you see the spark jump when you crank it? Did you check proper fuel pressure, use a gage and you have fuel injector pulse?
Any applicable trouble codes?

Did you check for spark at any ot the spark plug wires/ coils? If there is, check for fuel pressure at the fuel rail. Take the port cap off and connect a fuel pressure gauge. If one is not available, with a pocket screw driver deppress valve at port and observe if fuel pours out. If no fuel comes out at all, check your fuel pump circuit. Check for good ground and power at fuel pump connector. If power/ground are ok, replace fuel pump. If spark and good fuel pressure is present, there is the possibility of engine mechanical issues(jumped) timing chain). Also, a plugged catalitic wont let engine start but its very unlikely thats your problem. Start with your basics: spark, fuel, engine mechanical and catalitic.

www.ask.com/mfg.name/make/model/error/code/p1000/

did you check the rotor cap, check points and condenser if you have 1,
solenoid, check the wiring that plugs into the alternator, check all ground clean of rust, dirt, grease, oil,
if you have carburetor system, this a float issue, not set right

I KNOW YOU SAID YOU HAD GOOD FUEL PRESSURE but what if the pressure is to high???????????????????

contact me for more info if these ideas dont work

Did you disconnect/remove any other wiring/sensor when changing the pressure switch? Try disconnecting the plug from the switch and retry starting. The oil pressure switch on some GM products worked as a backup for power supply to the fuel pump in case of relay failure but I don't think this model uses that system. It could just be coiencindental that this happened. You need to determine if there is no fuel supply or spark causing the no start. Remove a spark plug wire and hold it over a ground and crank the engine. If spark is there it is a fuel problem most likely. Remove cap on schrader valve on fuel rail and press valve to determine fuel pressure/supply. If one aspect is not there, you will have to diagnose further

maybe cranksensor

I'm glad you figured it out. However, the "white stuff in the tank" sounds like somebody might have put sugar in your gas tank. You should probably pull the tank down, drain it, and clean it out real good. Otherwise, you are likely to be taking your fuel rails and injectors apart again.

it could be a blocked exaust system

Shootin in the dark. I suspect there is a faulty ground between the engine and the body. Try a jumper cable. If no go, then check for fuel an spark. Really need more info.

Find the pressure test port (looks like a tire valve) on the fuel distribution rail over the injectors and place a can over the open end of the valve. Press the inner pin to release fuel into the can. If the pressure seems to fall rapidly, replace the fuel filter. Is the check engine light on? Rent a scanner, read any code(s), and pursue to repair(s). A bad crankshaft sensor or camshaft sensor can prevent the injectors from firing fuel into the engine.

i do believe that's what it is if it will not let get a diagnostic or if it will not let you access the computer the computer is bad.