Idle/acceleration issue

Hi all,

I have a few symptoms that I was hoping someone could help me pinpoint. When at a stop light with my foot on the brake, I can feel the truck "lobbing" slightly. When I take my foot off the brake (no gas applied), it does continuous light surges (i say "light" because this is more of a feel than a see, but highly noticeable). Once you actually apply the gas, it smooths out-ish. When on the highway and between the speeds of 50-65, applying a little gas will cause the whole vehicle to shake. No pressure on the gas, or pushing harder on the gas (~2500-3000 RPM) will make the problem "go away" (I think it is lessening to a point of harder detection). I replaced the TPS thinking that may be in the right direction but the issue is still there. Before spending any more money, I thought I'd see if anyone else has experienced this. I've had recommendations from the fuel pump to the transmission so I'm hoping someone has some insight.

Thanks in advance!

 

In case anyone comes across these symptoms, I thought I'd share my fix. Turns out my truck was throwing codes but my check engine light was burnt. The problem was a misfire on cylinder 6 due to a faulty plug wire. Switching the wire allowed me to identify and after many other part replacements and cleanings, this got me back to running like a dream. Hope this helps someone in the future.