98 chevy c1500 5.7 vortec long cranking

[Markus Escamilla]

1998 c1500 5.7 vortec long cranking

My 98 chevy recently started bogging down on the highway so I replaced the fuel filter and it quit bogging. Now the the problem is cranking. After sitting for a few hours it cranks over for like 5 or 6 seconds before starting and it will run and drive perfectly fine. If it sits for less than 2-3 hours it will fire up as soon as the key is turned. There are not any codes shown so it hasn't picked up a misfire or lean conditions code. I checked the fuel pressure at the test valve and it shows 50 with the key on engine off and it stays at roughly 50 the engine on. Maybe the test gauge was inaccurate? It did look like its been used a lot since it was an autozone rental. The fuel pump was replaced with a cheap one from 1aauto 3 years back. Maybe the fuel pump is getting weak? What should i do? There is no lack of power that I have noticed.

[CamGTP]

If you prime the system like 3-4 times, does that make it start faster?

[Liam the red]

I would try a leak down test. Connect the gauge, pressurize the system by turning on the key, then turn off. Watch the gauge to see how fast (if any) the pressure drops. 

A fast pressure drop or a lot of pressure drop could mean a faulty pressure regulator or stuck injector or a host of other related things.

[Markus Escamilla]

On 11/20/2021 at 3:01 PM, CamGTP said:

If you prime the system like 3-4 times, does that make it start faster?

It doesn't start faster after priming it several times. It tries several times to start before it actually does.