2006 tahoe problem

[mrdsl23]

I have a 2006 Chevy tahoe with a 5.3. It takes it a long time to start. When I turn the key it just spins over and over eventually it starts. I have changed camshaft sensor, Crankshaft sensor, fuel pump, all vapor canisters and checked fuel pressure. Still haven't solved the problem. Can u help?

[kstruckcountry]

What was the fuel pressure?

[txab]

Fuel pressure reading is checked key on engine off, btw

[mrdsl23]

56 psi with engine off

[mrdsl23]

Can anyone help me with this problem.

[8.1HD/ALLISON]

What brand fuel pump? Im thinking the pressure spec is 62 psi? Id have to look it up. Does this happen all the time? Hot or cold? Assuming no codes?

[efritz]

check the fuel pressure after it has sat for an hour or so, fuel pressure regulator leakdown can cause what you are experiencing. If it is alot lower, then replace the regulator, 5 or 10 pounds is fine. Another test: (after the truck has sat overnight) cycle the ignition from off to run (holding run for 5 seconds or so) twice before starting. if it fires right up, fuel pressure is going somewhere, likely through the regulator!

[mrdsl23]

The only regulator they told me it has is on the fuel pump. I've changed it.

It does this all the time but every now and then it starts fine

The code is p0342 camshaft positioning sensor bank 1 but I've changed it also.