Recently my truck has began having an issue where it takes a few seconds of cranking before starting where as before it would start as soon as you hit the key. I do have to wait the wait to start light comes on primes the pump and then goes off before cranking. If i don’t wait for the light come on and go off it will never start. When the truck has been sitting it always starts right up, but for example if I’m running errands in town and shutting it off and restarting that’s when it takes longer to start. At times it’s not started at all, so I let off the key and the pump comes on for 20 seconds or so and it starts right up as long as I crank when the pump is running. 

 

I recently changed fuel filters, it has a fass 150 lift pump, it seems like it’s maybe losing prime or something? Suggestions are appreciated. Thanks

Sometimes it wont start.

 

Over the 15 years of owning my 02 longer start times have always been battery, starter or battery cable issues.

 

Never had pump issues the only time it would not start it was one dead battery or start contacts.

 

The only other times were in cold temps fighting battery cable issues.

 

Ohhh injection pump ounce caused no start.

A leaky full line will do it too. The first time is was the return line tee that the VP and head return lines join behind the fuel filter canister. The second time was a bad cross over tube o ring. The odd thing with yours is it should be harder to start after sitting over night. Are you parked nose down over night? Do you have a fuel pressure gauge?

 

The WTS light is an ECM issue. You could send it in and have it tested. One day the light may not come on at all. When, who knows.

 

And as @Evan mentions a weak electrical system can cause this also.