HELP! F150 5.0 Intermitantly Surging, Engine surging
 

I have a 91 F150 4X4 4spd with a 5.0 that intermitantly surges only when driving not when idling. I tested the TPS and EVP (EGR) and all is good. I pulled out a code 63 and 31 from the ECU. The truck idles rather high. Also, there is no vaccuum coming from the vaccuum line that attaches to the EGR even when idle is increased.
Any help would be appreciated.

Mike