Map sensor wouldn't cause a long crank anyways. Low fuel pressure or bad injectors and a slow starter are all that will really do that. Fuel pump check valve's fail nearly 100% of the time on dodge pumps so its likely that. It also could be leaky injectors but that would cause other issues as well. I have never personally seen a starter fail on this generation of trucks so I would lean towards the pump having a bad valve.

 

I did a reset out of curiosity. fired right up after sitting all night. Then shut it off for a while,went to start it up to run to town and back to long crank again. Are you able to replace the check valve itself or is it built in?

 

Part of the pump module. I don't think you can purchase it separately. Could install one inline though......

 

GP Sorensen was the only one I can really find.

GP Sorensen Fuel Pressure Regulator 800-432

 

Its a component built into the fuel pump. Sadly you have to replace the fuel pump to get a new one.

 

Actually, the check valve issues works the opposite way. It causes the lines to lose prime after sitting for a long time. So the long cranks would happen after sitting overnight and not so much when you're running around.

 

Depends on how bad it fails. It can range from slow leak to stuck wide open. I've even had one that would work for a week then fail for another. Usually though yes it will lose prime overnight or after sitting for a few hours.

 

Looks like I can get a new pressure regulator for the pump. Didn't have time to test the fuel pressure yet though. And if it is bad I'm going to try the warranty route through delphi first. If I do test it and it is the check valve, can I add one just up from the pump inline? Or would it restrict flow to much? Is there a good valve for the application?