Baffled by intermittent throttle response

[Broad Oak]

I purchased my dog last August. Since then every spare minute has been spent getting it ready for service.  Now that I'm ready to make some money instead of spend it, I have run in to a reoccurring issue.  For days  this truck runs like a top.  Then you get in it fire it up and there is no throttle response.  When I kill the ignition, the motor dies then fire up and continues to run for 2-3 seconds and then dies.  These symptoms have come and gone several times with no rhyme or reason.  Two times when I have left the engine idling the issue corrected itself, only to revert back days later.  The symptoms only present after the truck is parked, never while operating.  Any help would be greatly appreciated.  Thank you.

[Mackpro]

RD's with ETECH engines have a serious flaw inside the cab with the way the VECU is mounted. If you pull down the kick panel in front of the passenger seat. You will find the VECU and ABS ECM.  From the factory the  black plastic VECU with the harnesses 3 plug in's facing up. If this is the case , water from leaking windshields drip right into the VECU. The VECU needs to be facing down. If yours is facing up. Pull the 3 plug in harness connections and check for green pins and water damage. This causes throttle drop out and engine not turning off when the key is switched off. 

[Broad Oak]

Thanks Mackpro I'll check it out in the A.M.