1994 E-150 5.8/351 E4OD

History: I had a bad computer, Installed a reman one and that cured the hard shifting

issue I had, but now I am having a surge problem. When stopped at idle it will surge

forward like its being given gas, It has did it one or two times every day in the week

since I have installed the reman computer. Today I drove about 10 miles and it did it

once but this time it was really bad and scared the crap out of me.

Yesterday I hooked back up a vacuum hose (related to the OBD1 code 311 I am getting) I found disconnect and installed a new PVC valve and grommet, thought that would fix the issue.

A few years ago I replaced:

Ignition coil
distributor cap and rotor
Idle air control valve (it was very clean when I removed it)
Ignition control module
Plugs and wires are only about 4 years old
Cleaned the throttle body, I really didnt need to because it looked super clean already
New radiator, thermostat and hoses, plus bypass hose.

I am getting a code 311, Thermactor system fault. This code was before and after I installed the reman computer, but before I did not have this surging problem.

I am also getting a error code 628, excessive clutch slippage. I found a link that says that might cause A surge issue. Does that sound right?

I am wondering?

Should I disconnect the battery so the computer can re-learn?
Should I keep looking for vacuum leaks?
Should I reinstall the old computer?
This is very hard to diagnose because it is very intermittent.

Thanks for any help.