2000 f150 ext cab 4x4 4.6L triton wont start

PCM relay can do this. It would not hurt to clean the MAF sensor with crc MAF sensor cleaner and the throttle body and IAC with throttle body cleaner. You have to remove those last two so gaskets for those need bought but its an easy job just do not touch the MAF sensors' two tiny bare wires. These can cause a no fuel issue to, the throttle body also has a TPS sensor, There are some test you can do on each, you will need a chilton book

If you have a way to test your crank shaft positioning sensor, do it, if not just replace it. Assuming you have fuel pressure at rail

Thanks for the replying... As far as the PCM I switched it out with a spare (I assume all the black boxes will work seeing as they are identical) that was in the box also switched it the other identical fuse in the box.. Nadda...As far as testing I really don't have the tools at the moment. I assume your tests mean a multimeter? As far as the crank shaft position sensor. I have fuel pressure at the rail, not quiet sure how much no pressure gauge. It will fire on starting fluid, so that means it signaling the COP to fire correct? It seems im not getting signal to the injectors. Anyway to test Injectors without a multimeter?

There is connection right above the frame from the harness to the fuel pump. The plug was not plugged in all the way from day one on my truck. Changed the fuel pump and it started. A week later it quit. Got probing around and found that plug. Wiggled the wire and it started. Found the plug and pushed it together. CLICK! Fixed.

You would've found it by checking the fuel pressure

Mine is still not running ...ok heres a total run down... Fuel pressure test went as follows... Will not hold pressure .. Can't get it to build past 30psi. Fuel pump runs half a second and shuts off.. I have 12.3 volts at I trial switch on to the pump then nothing. Pcm relays are good new fuel pump new fuel filter new pressure regulator new camshaft position sensor.... Tested injector power supply with no readings.. Inertia switch is good... Ecm is all that's left correct?

I just do not think the computer will be able to stop the pump from building pressure unless it is not letting it stay on and if all relays are good I am at a loss, most times its a relay that will not stay in the on position or flip to the on position or flip off too. May could try a known good one to see if it works fine. I would not rule it out but I also would not want to throw out big money on a computer either. May can bypass the computer/and relay all together for a test and run 12 volts to it on a switch as not trying to crank it either but test to see if you build the correct pressure or more than 30psi. A injector may leak maybe?

I straight wired the pump the other day. Did not have fuel pressure gauge hooked up bit ran the pump long enough for it to ha e fas push through the whole system and back into the tank via return line... One bad injector woildnt keep it from firing at all would it?

The pump cuts one and shuts off all.most immediately....

When you turn on the key no crank the pump will prime for about 2 seconds. When key turned to crank whether the engine is starting or not the pump will come back on, This needs to be confirmed to rule out the pump and relay. No the injector bad will not keep it from cranking up just like one bad spark plug will not keep it from running. But If the (all) injectors do not get power then they can not open to release fuel.

I would go back and look for all fuses you may have missed under dash and hood and recheck them, The PCM has a relay and a fuse. I would look for Bad grounds or wires that lead to ground if bad can not complete circuit, the injectors need power to open, check the wire harness see if looks like it may have gotten burns ect. I would locate the PCM and check for fuses there and grounds here too as the injectors get their ground threw the PCM. I will keep thinking about it and anything comes up I will post it. Never tried it but may can locate the main power to injectors and ground and run another ground and power from battery and see if it cranks up. if so you know its the Wiring from PCM to injectors or the PCM or even its relay & fuse.

Pump does not come back on when trying to start. No power to the injectors when trying to start.. I also tested the injectors themselves and the all tested out fine. I've swapped out the PCM relays with 2 others so surley they all aren't bad.. You can hear and feel the relay open when switched on and close when switched off... I've checked every ground I can find. So I have power to the relays so what could be shutting the pump off...

Must be the PCM or short.

Ok guys .... Went and ordered a new Ecm... Was programmed to my truck ( von number mileage yada yada ) and flashed already.... At least that's what I paid for! Now I get it and says the PATS has to be programmed and says that " Ford PCM part numbers with a "F" suffix require flash programming to the specific application for proper vehicle operation. Ford programming requires proper vehicle identification. What do I need to do? Is this something I can do myself?

Ok everyone.. Found the answer to my problem. Ground wire was broken in the kick panel drivers side....

Happy you found it.