I just picked up a used Ram a month or two and it had cracked heads so we dropped a new engine in it. It has the 5.9L V8 and runs fine when your giving it gas, but when you let off fast it wants to stall out and die. This is a big problem when at stop signs or lights. It doesn't do it all of the time, but it is pretty frequent. Some days it will start without a problem, other days you will have to give it gas and slowly let off until its at the right RPMS and it will stay there. However, hit the gas and let off and it will quickly die again. There is one temperature sensor running to the ECM that is not plugged in due to the fact that the new intake did not have the extra slot, but im not sure if this could be the problem as it shows the same symptoms running both cold and when warmed up. It is NOT the TPS, i have already been down that road and am 100% sure of that. Sometimes if i clean out the throttle body with some carb cleaner it will run better, but after 100 miles or so will start stalling again. Ive been told its the fuel pump or filter, pressure regulator, possibly a relay... im running out of money and i have to get the truck running, somebody please give some definite answers.