Have a 99' 1500 Club Cab 2x4 V8 318. No problems until suddenly...was driving to work and began losing power. Tried to excelerate & truck began "spark-knocking". Could not exceed 15mph.. Engine acted fuel starved. Motor idled fine until I disconnected battery to try to reset computer. Now, motor did not want to stay running, idles very hard. Ran OBD-said "no codes". Fuel injection pressure test ran between 40-45 psi. I'm stumped!

 

I think your fuel pump is supposed to be 44-54 psi. It sounds like you're on the low side of the scale for fuel pressure. Do you hear any rattles under the rig? Have you checked the cat and muffler for restrictions?

 

i'm guessing that you did the fuel pressure check at idle, if so, then you have no idea what kinda psi it is makingunder load, you should check the flow rate also and see if the pressure stays the same. but chances are you need a new fuel pump