Fuel pressure problem

check 12V at pump terminal when on/cranking

hear/feel pump operation (if external to tank)

if low pressure (carby) disconnect fuel line and observe flow. If high pressure (FI) connect fuel pressure guage and observe pressure. Check fuel filter while doing all this. Filters are the source of many problems that start people messing with fuel pumps.

need to check fuel pressure before trying to start and see if it's bleeding down or staying pressurized hook gauge on and check periodically before trying to start, seems like mine done that and it was a b ad fuel pressure regulator on the fuel rail, 5.3 ? it's on drivers side rail with vacumn line erunning to it about the size of silver dollar diam.

Get it checked with a mechanical gauge. Replace sensor.

also u may want to check the regualtor take to a mechanic and have him put i pressure guage and to make sure pump is pumping right amouth of psi. you could have broke some of the plastic on pump when putting in. If good psi then maybe relay or regulator under intake.

here is the next step, you buy a fuel pressure test gauge from a parts store and hook it up at the test port at rear of the engine on top, it looks like a tire valve but metal, will have a plastic cap on it ( or should), test the fuel pressure should be around 50 PSI at idle. How is the fuel filter, ever been changed? it is due every 30,000 miles

Check the wire behind the guage.If not tight it will make the hand bounce.

todays fuel pumps have the signal gauge togethoir the only way is to change the fuel pump

When you hook the pressure test guage to shrader valve on fuel rail what it reads is what the pressure is from pump, around 60 p.s.i. all you need to do is hook up the guage and turn on key, you do not have to turn engine over, and if pump is good it will shoot up to 58 or 60 right now.

You will need to do a fuel pump pressure leak-down test, the pump must not loose more than 5 PSI overnight, u will need a cheap fuel pressure test guage, the test port is on the fuel supply rail to the injectors on the intake manifold, it looks like a tire valve but metal with a plastic cap on it, u may be able to borrow this guage from Kragen, Autozone or a parts store like them, if not they are very cheap, less than $20 US. Run the engine with the test guage hooked up, turn off the engine and then check it in an hour or so, if it drops more than 5 PSI then u will need to replace the fuel pump in the gas tank. One note make sure the connection for the guage is tight with no leakage or the test is invalid

check the crankshaft sensor