Surging at 3500k after cam

[tep98ws6]

I finished my rebuild and car WAS running great. Just finished installing a water pump and new 160* thermostat so as I was allowing the thermostat to open and burp the system of air w/ defrost on high, the car started to surge at 3500k in closed loop. It will stay at 3500k until loop opens and idles at 780-860RPMs very well on its own ... just I don't know what this surging is all about. I put a 231/231 .621/.621 112* PBM Cam in which came with a sheet stating that the cam would change the firing order.

Is this something that could cause the surging? I've smoked the system for leaks, none to be found, throttle body is clean... We had a similar issue in class on a Z28 that has a much smaller cam but also changed firing order so we extended the coil feeds to swap the cylinders and tuned in the correct firing order. Mine hasn't received a new tune yet, probably has 1-2 hours on it since rebuild and less than 10 miles. Im nervous about driving it when it is surging this high and was thinking of doing a stand alone tune on my own w/ the PCM only then reinstalling it and seeing if that will help it any I'm unsure of what tables to do w/o having any reference.

Im just confused by the issue. Halp

[0verkill]

the fireing order can have a big part of it but i dont remember what it changed im almost sure its just 2 that change get the fixed and the rest should be in the tune. i would not try and drive it till you get the fireing order right 1st.