Weird Cranking issue

[brh11]

I have a weird starting issue that only seems to happen when I let the truck sit for more than 10 minutes.I'll try to add a video but it seems to either crank more then it should or idles super low then catches up to normal. New spark plugs, oil replaced but starter seems to be good when starting it again after the issue. My guess would be the oxygen sensor but could be wrong.

 

[Doubeleive]

I would suspect low fuel pressure, next time try turning the key to start but don't start it right away, let it sit with the key on for a few seconds first then try to start and see if that makes any difference, if it does make a difference then verify/follow up with a fuel pressure test there is a port right on the fuel rail.

 

[swathdiver]

Might be time for a new fuel pump Brandon.

 

[buddyhotrod]

I agree

 

[iamdub]

Sounds like the fuel system is bleeding off it's pressurized fuel (also known as it's "prime"). By the way it starts with the extended cranking and low idle RPM, it sounds like the fuel is leaking into the intake manifold, which would be a leaking injector(s). I'd do a thorough fuel system pressure test to first check the pressure the pump is putting out when cold and when hot and also to see if the pressure drops after X amount of time. If the pressure is good but drops off with the pump off (key off), the fuel is leaking either into the manifold or back into the tank. You'll have to isolate and test to see if it's the injectors or fuel pump assembly, which I believe has the regulator built into it as well as the check valve.