[SOLVED] 4.0 SOHC is long cranking when hot

[BTR]

Guys, problem finally solved!
Thanks for all your help.
It turned out that one injector was extremely leaky.
And now - Explorer idles right away!

@slisman - I have almost the exact same scenario as you had. You didn't say how you determined (specifically) that an injector was leaky. Nor did you say how you determined WHICH injector was leaky.
I've ruled out everything posited in this post (and more). I'm at the point of needing to determine IF one or more of my injectors is leaking... and WHICH injector/s it is. Can you share the diagnostic procedure/s you used to answer these two questions?

 

[slisman]

@BTR you can try @koda2000 's way to verify injectors (described in this topic):

"You might try removing the fuel pump relay with the engine running (with the engine at full operating temp) and letting the engine use all the fuel in the fuel line. That way there would be no residual pressurized fuel available to leak through any fuel injectors. After letting the engine sit for an hour replace the FP relay and try to start it to see if it makes a difference.
Note: Before attempting to restart, turn the ignition key from OFF to ON a couple of times to prime the system."

And to confirm - you can try (also @koda2000 's tip ) to start engine with gas "pedal to metal" when you are quite sure that it would crank for long time. Our ECU is not supplying enigne with additional gas. So if engine would start normally - it means that there was fuel in engie delivered by leaky injectors. If engine would crank without idling - it means that injectors are in good condition (many people do such thing during cold startups - oil is distributed within engine before idling).

I think that leaky injector should affect your fuel trims (e.g. in Forscan) - you could specify which bank has faulty injector. Your trims values should be way higher than desired.

But I don't know if you can determine which injector is leaky with 100% sure.