Turns over, doesn't always fire up. Makes me :(

[C3ntury]

Need some thoughts. I have an 09 1500 V8 that has trouble starting the past 4-5 days, not throwing codes (have thrown ignition codes in past, which new plugs solved). My spark plugs (NGK) are only at 15k. Most times, while turning over, it won't fire up till I hit the gas just as I turn to crank. The battery tested fine. I'll take a look at the plugs this Weds. along with the coil packs, but anything else I should look for while I'm in the trench (clogged injectors?)? It was brought up to me that the TB could be dirty, but it's not the TB. Cleaned, it wasn't that dirty, and today problem persists. Matt @ Moes said to leave the key set to "On" for 15 secs, which will prime the fuel pump. It's started right away having done that twice now. Thing is, wouldn't I have other issues going on if it was failing? Truck runs strong otherwise.

 

[Arth]

Possibly.

Then again maybe not.

I had an 05 suburban that would not start by just turning the key straight to start. I always had to turn it to on and prime the system. The thing ran perfect once it was running. Turns out newer vehicles use a return less fuel system or something like that.

Anywho did a fuel rail pressure test and it would lose prime once you shut it down.

Only way to fix that is replace the fuel pump since everything regarding these newer fuel systems is centered around the fuel pump.