I have 2000 Ford Expedition that will not idle and only starts or couple seconds.

No advice about messing around with gasoline until you answer. You did all the stuff yourself or you had it done for you by someone else????

I did it myself but I am a mechanic so it's kinda both ha.

ok ---so lousy fuel pressure , is that high of 40 close to specs. (iffy)

30 is actually low end specs.

It's a pressurized sealed system from a to b, so it's losing pressure or not creating enough? Hole in the very top of the gas tank so you don't notice any evidence of it ?

I have had the gas tank out three times and haven't noticed any wear marks that would indicate a hole in the tank. I believe it's creating enough pressure it's just not maintaining or holding enough pressure, I don't have any leaks and do not have a gas smell so I am not sure where I am losing the pressure at.

you got a leak but it may be in vacuum that the new fuel pressure regulator is working from.

the vacuum in the line goes down with higher rpm & pressure should go up, so your pressure isn't going up because the vacuum line is holding vacuum? if you disconnect the vacuum line when the engine is running will the pressure maintain ......just spit balling. see what the pressure does when you remove the vacuum line from the regulator.

I want to go through where I would have started before spending any money. By the time you posted YOU HAD ALREADY REPLACED a bunch of stuff I would have started with looking for anything obvious like loose hoses,wires,manually reved the throttle,pulled the air filter,pulled the vacuum line at the fuel pressure regulator to see what that did,checked for gas at the rail, SO FAR NO MONEY SPENT....... Then I would have run my codes. I am assuming I just noticed a offness to my idle ( and I didn't have a warning light.)...........so no money spent yet. ......Now you are at where I would have been except you've replaced a bunch of parts........after you pull off the vacuum line at the fuel pressure regulator and see what happens you are going to have to check your codes. BUT YOU HAVE PUT IN A NEW PCM so I would think you are going to have to run her around a bit and see what the sensors pick up and then check your codes.

I am hoping the code(s) will point you to an area that you haven't looked at yet.

I didn't just through money at it the fuel pump was bad and the fuel pressure regulator was replaced because while unhooking the vacum line is caused no change in pressure and when I crimpped the fuel return line it would hold pressure. That's when I set out on the journey of looking for a wiring or short problem. I replaced the PCM because I had no Volts to my Cam sensor or Crank Sensor, I had good continuity through the wires all the way to the brain leading me to assume the PCM was bad. I wish I could get codes on it but it will not staying running long enough to throw codes, trying to force it to run by reving it does nothing it dies no matter what. The old codes were missfire on all cylinders (which I believe to be due to the fuel pump going bad) and O2 sensor bank 1 and 2 were to lean (again I assumed the fuel pump was the cause of those codes). I'm probably over looking something simple. I am leaning towards the MAF sensor or the O2 sensors but again even if those are bad I would think it would run probably run bad but still run. Oh and I checked the coils on the plugs all but one was good and the plugs were ok so again a problem but not enough of a problem to not make it run. Back to the fuel pressure it is maintaining at 30 to 40 which is in specs I sent the new regulator back and got another one which seems to have fixed that problem.

I just don't understand why it will not run it has all the basic things to run if only baddly but at least run so it can throw a code and get me pointed in the right direction.

I hate to ask but,you didn't by accident mess up firing order at any time, and have you actually got fire and fuel in each cylinder,have you checked compression.

No I made sure not to mix the order. However just now I made it run by sufficating it from air it ran badly but ran checked the wave on the MAF sensor by back probing it and it wasn't any good. I believe I am now on the right track.

I am a d.i.y that has no where near the kind of equipment you have access to ; so, your electronic testing ability is way beyond what I can do in a driveway with my eyes and ears. In my day we'd call that chokeing it to death, but, we actually had a choke. So why isn't it getting gas into the cylinders. Got a noid?

Don't waste your money on chips And keys and the anti theft system if your car isn't cranking its probably your solenoid switch...

Solenoid switch ? Where's that one? Expedition 2000.... won't start after a good drive from Vegas to LA .any suggestions?

I have the same problem too.

Anybody help before spent money here.....

Idk but I also have a 2000 ford expedition xlt triton v8 5.4l and I could be going down the road and loses half power and won't have power to clime a hill on interstate just slows down untill i shut the engine off and start it back and also it will sometimes spit and sputter like it's running out of Gas then slowly pick back up and running fine