I will of course start searching within the forums .. but I also wanted to pose this question for assistance.

We have a 2005 Z-71 with the 5.3 motor. Having an issue starting it.

1. Will not usually start on the first turn of the key.
a. But it will start on the first key start if I turn the key to the start position, but not actually starting it. I read that tip on a forum, possibly this one. I do the "false start" 3 - 5 times and then when I do finally start turn it all the way it starts right up.
b. Have replace the starter, that is how it presented itself initially and the resistivity values were just out of spec.
c. replaced the alternator, the voltage output fluctuated at one point during the troubleshooting.
d. Replaced the battery, was still under coverage from Costco
2. Borrowed a fuel pressure gauge from local auto parts store and connected to valve on fuel rail but there were no readings from their unit.
3. Will have to wait to purchase my own till Friday.
4. Once started it runs fine with no apparent loss of power.

I am thinking that based on what I have read on this forum and other sites is that the most likely culprit is the fuel pressure regulator. Just hoping for some additional troubleshooting tips from the other members.

thank you VERY MUCH in advance for all the help ...

 

Do the fuel pressure test first. When my truck was doing that I changed the fuel pressure regulator with no help. The fuel system was losing pressure with the pump off. You can change the fuel pump or add a check valve in the fuel line, which is what I did to correct my problem.

 

oldchevy .. thank you for the response .. can you explain how you added the check valve. I am SURE that will be easier then dropping the gas tank ... I hope

 

I bought a check valve on Ebay that is rated for fuel. You will also need fuel injector rated fuel hose and 4 hose clamps. My truck has the fuel filter just before the gas tank. I put the check valve between the filter and the tank. The check valve should go close to the tank. I cut the steel line with a tubing cutter and put the check valve there with the hose and clamps. Fairly easy to do.

 

Sounds like it's losing fuel pressure while it sits. Turning the key to on and waiting, allows the electric fuel pump to bring the pressure back up.

 

My 05 is doing the same thing. We just for 2 or 3 pings of the key in alarm and it starts right up. I have a three year warranty so I am not worrying about it at this time.