I have had a surging between 45-50mph for a while, Installed the HRVP44, the surge got worst. Now between 45-55mph. This is in OD and just cruising along. If accelerating - no problem. Thought it might be the TPS, I reset the Apps - corrected the voltage, cleaned all grounds. Was looking at running mystery switch so as I could lock it in to check if the surging continued. Now this morning I took a little time to listen to engine. The truck will idle smooth most of the time with a little rough spot every once in awhile. Put the truck in gear at idle, sometimes misses a little but not all the time. Put the truck in drive, While holding the brake, Accelerated slowly up to 1000 rpms with a very slight jump in the tack. Contiue accelerating up to 1500, smooth all the way up to 2000 rpms. Did the same in Reverse. Took the truck out of gear and slowly brought the rpms up, truck missing bad no matter how high the rpms go. So I guess when I'm traveling down the road in OD and just cruising the truck is not under load and engine misses causing surging. As I said it did this before installing the new VP and got worst after. Do you think it could be a bad injector? Any words of wisdom?

Regards,
gene