I replaced fuel pump but did not start,poured fuel in the air breather and it stays on until the fums run out.checked the pressure on the rack and nothing.is there a relay that doesnt work a fuse or is it the fuel pump

Do what I do at times it won't start. Recharge the battery first. It's just that the fuel pump hasn't put enough fuel to fill the lines and injectors yet to begin with. Remove the cover on the air filter. Pour 2 ounces of gas onto the air filter in a circular motion to soak the filter and stick the cover back on the filter and then crank the engine and it will start and run until the fuel vapors have gone from the air filter. If it still runs at this point, it worked for you. If it doesn't keep running, check the fuse on the EFI that it's good. If good, go back to gas the air filter again until the engine runs on it's own.

is your security key lamp lit on dash.

Fuel pump relay faulty, when the engine starts the oil pressure switch takes over fuel pump circuit and sends power to the fuel pump

What is the fuel pressure when the engine is running ?
Has the filter been replaced ?

Runs on the gas you pour in, or keeps running until you turn the key off ???
If the fuel pump relay fails, you would have to crank the engine until you get oil pressure to provide power to the fuel pump.
Do the injectors spray when you are cranking it ? Have you checked fuel pressure when the key is turned to start ?

I think you've identified your own problem. In your description of the problem, you indicate "no fuel pressure on rail".....

First things first, try replacing the fuel filter. If this doesn't do the trick, make sure the fuel pump is actually pumping (you indicated that you hot wired it with a 12 volt DC supply and it ran). Running is one thing....pumping fuel another. To properly identify issue you need to know the cranking fuel pump pressure. If you can get it to start it would also be a very good idea to check out the fuel pressure regulator.

When you turn the key to the "ON" position (don't crank it, just to to the position where it would run) do you hear a few seconds worth of pump motor activity?

If it tried to start when you introduced fuel into the breather, then I think it's safe to say you have some sort of fuel delivery issue.

if diesel most probably air in fuel system,first check all fuel hoses for tightness ,if you can twist any hoses by finger pressure tighten.allso replace any damaged fuel lines ,check all bolts on the injectors for loose play ,allso check fuel tank breather for blockage does it improve with fuel cap cracked open.do not drive on the road like this !!.Finaly check your lift pump which fail quite often.Have you checked your fuel filter for dirt if black or dark replace.

Your vehicle doesn't have a carburetor. What you poured gas into was the throttle body. Does it stay running once it starts? You really should check the fuel pressure to be sure but not everyone has a gauge. Changing the fuel filter would definitely be a good start. If that doesn't do it, check the fuses for the fuel pump and check the fuel pump relay. If they check out make sure the power is actually getting to the fuel pump, check the ground wire of course also. If you have good power and ground at the pump and no fuel you will have to replace the pump most likely.

Remove breather/air hose to carburetor/throttle body -- pour about two tablespoons of gasoline into it. Reattach breather/hose, start engine. Repeat until engine remains running.

Charlie

have fuel pressure tested pump may run but may not have enough pressure to activate injectors,also check timing chain or belt!!Best of Luck!!!!