Hi everybody.. I am looking for some help here.  I have a 2000 f150 CNG duel fuel.  This week it started dying at idle  even while driving as I am decelerating it just dies.  Backing out of the driveway, it just dies. So I took it to the dealership so that I could give them all of my money and have no results because thats how I roll.  I told them I thought maybe the TPS, because it dies in regular gasoline mode as well as CNG.  They called back and said they think it is the compu valve.  Jack asses.  Any help would be most appreciated.  So far they have replaced the coalescent filter, fuel filter and then flushed the CNG system.  Still no better.  I have managed to keep it running while at lights by reving it up to 1200 rpms and holding the brakes.  Please help with ideas.

P.S. there is no check engine light