Engine Stuttering, no throttle response/popcorn sounds from hood
I have a 2003 Ram 1500 with a 5.9L. I have had an ongoing issue with my truck. It always starts up fine on the first turn of the key. Except during the first few minutes of running it, I run into the same issue (usually when engine is cold).
The issue is: basically when I put the gas pedal down and there is no throttle response. The engine does not rev in rpm's, instead there are popcorn noises from under the hood. This goes on for about 2-3 min of stuttering and sometimes getting throttle response and sometimes not. Although after that little amount of time the truck runs fine, with only a little delayed throttle response every now and then.
I talked to my local mechanic and he said he thought it may be the fuel pump, so I had him do a fuel pressure test. The truck failed the test, so I spent a little over $300 for a new fuel pump and install. I thought this work fix it, but the problem still continues. Any ideas of what could be the problem? Is there something else that could have affected the fuel pressure test that could be malfunctioning, other than the fuel pump?
Thanks for any advice/help with this!