Not running - Cars & Trucks

The fuel pump only runs when the engine is being cranked or of course is running, it is shut off after about 1 second in the run only position.

run the fault codes and check for problem injectors

O2 sensor

It should at least run for several seconds after you turn the key on. It MAY run longer, but it SHOULD run for several seconds. If fuel demand goes down (engine not burning much fuel), the pump may not run after that.

you might consider replacing the fuel filter if its not been done in a while

Whats car year and model?

what type of vehicle and engine size? fuel punps are suppose to run while the engine is running. the full fuel pressure depends on the type of vehicle. some fuel systems only run 12-20psi while others can run 48-60psi

you vehicle runs smooth morning , and starts running very rough after the engine start be hot .

i got a 1996 and it runs a lil under 200 and its fine with me