Hard startup question

I have an '07 with the 4.0. If the truck sits for more than 3 hours or so you have to crank it over for about 3 seconds before it starts. It runs fine and there isn't a CEL. Cranks fine if you start it under that 3 hour window. I am thinking the fuel pump isn't priming, it starts fine sometimes because there is still enough fuel sitting in the cylinders to light it off. What do you guys think?

 

How many miles?
When you did your spark plugs?
What type of fuel 87, 89, 93?

 

52k miles, have been using 87. I was going to check the plugs this weekend but it seemed like more of a fuel issue to me.

 

Aha so you are 22K miles over the spark plug interval running 87.

Spark plugs are your first thing to check and most likely culprit. fill with 93 and see if start up gets little better.

 

I mis read your post, they were changed at 30k but the truck has 52k on it. I'll try the 93 for a tank too.

 

Sounds like you are losing fuel pressure.

Standard (running) fuel pressure is 41 psi, and rest pressure is 21 psi.

Hook up a fuel pressure gauge and make sure your fuel pressure does not drop below 21 psi while your engine is at rest.