Trouble starting a 1990 f-150 ford pickup no fuel pressure if you leave it set for a little while it starts sometimes stays running as long as you leave it running it runs but if it dies have to wait a while before it starts again it loses it fuel pressure tried everything

are there any trouble codes

Is there a SECURITY light lit on the instrument cluster ? What's the fuel pressure at ? Do you know how to test fuel pressure ? Does the check engine light come on when turning the key to run ,not start just the run position ? Did you try holding the gas pedal down a little way ? Go to you tube an check out videos on trouble shooting , engine won't keep running .

When it is not starting, spray a little starting fluid into the air intake then try again. If it fires then dies it is fuel trouble. if it doesn't fire it is lack of spark. If the fuel seems to be the source then suspect a loose connection in the fuel pump circuit. Try unplug and plugging the connections in the fuel pump circuit, fuel pump relay etc.
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Yes, it could be. The best and only way to know for certain is to have the fuel pressure checked. The pressure should be higher at start up, as with key on-not starting, than when engine is running. It may drop a few psi (5?) after the engine is running.
And very critical to have that fuel pressure at the injectors, for both easy starting and good running. If you have to try giving it gas to start, then something is wrong with either fuel pressure or with the computer controls for the engine. Odd as it sounds, the accelerator pedal-the old gas pedal-actually controls the air intake into the intake manifold of the engine. The computer senses all that and knows when to shoot more gas through the injectors...for a haappy ride. Good luck-check fuel pressure, check for trouble codes.

possible problems would be fuel regulator problems, bad fuel pump, clogged fuel return line, clogged fuel pickup screen, clogged fuel filter, or clogged or stuck fuel tank breather valve/line/cap. easiest things first. look for a disconnected, lose, or warn vacuum line from the fuel pressure regulator to the intake manifold. next try starting the car without the fuel cap. if that works you probably need to clean or replace your gas cap. next i would check for fuel pressure. u can buy a pressure gauge from autozone for around 30 bucks and some will just do it for you. if youre pressure is good while the ign is on but when the car starts it drops your best bet is something is clogged. if it doesnt drop then you may have dirty injectors, bad spark plugs, or a bad distributor. put some injectory cleaner in there are run the car a few times, replace your plugs and wire, and have your distributor tested at autozone. if all that is fine/doesnt change anything you have an idle problem somewhere. test this by pressing the gas down a little bit while starting the car. if it stays running then you have idle problems. if so just comment and i'll help you out. i hope for your sake your regulator vacuum line is just unplugged or leaking. good luck to ya

replace the fuel filters sometimes little particals get into them and clog the fillter after a few mins running it then blocks the opening and strarves the engine for fuel

Depending on the mileage you might want to check the timing belt or chain

does it stay running if give it gas. Is this just an idle problem ??

could be one of several things,first check the fuel filter ,then the fuel pressure regulator, the the dis cap and rotor or even the pickup coil

fuel pressure regulator