Wont start when warm

[MaicoDoug]

Hi guys, I have a repeatable issue with starting. When this 2007 4.0L sits in the sun, sometimes the engine won't fire up. Cranks fine. Sometimes it tries to kick over slightly. If I keep the ignition in the "run" position in preparation for the second attempt, it seems to help it start. In prior second attempts in starting, still doesn't want to start, one has to hold the key in the run position for a couple of seconds. Q: Is this a fuel pressure switch of something? I'll look for codes, but never saw any before. The motor has a new set of plugs, coils, wires. Still the warm starting issue persists. So I guess it's time to start getting into the fuel system. I have read about some sort of known issue with a "fuel pressure switch"?

--EDIT; The coolant temp sensor possibly, will have to pull the manifold to replace. Will be a project for the very near future.

Thanks for everyone's' input. - Doug

 

[bills4065]

You got to love these kind of headaches, Doug. some of these mechanical returnless systems have pressure regulator as part of the fuel filter while others the pressure regulator in the tank. Do you which set up you have?

 

[franklin2]

Here's a fuel pressure tester at Harbor Freight for $24.00