97' WIA Engine dieing problem codes 31-36

I have a 97' wia Volvo with a VED12(first Gen) and a Volvo vt1414 trans. Last six on vin 735722
I have taken it to two dealers they say that they can't get the computer to talk to their software. I have had a mechanic that works at the company hook up a non specific diag reader and it came back with high voltage or ground fault for all six cylinders which is what my push button diag shows codes 31-36. 31 being cylinder 1, 32 number 2 so on though 36.
My problem is that the truck runs fine bobtail but I put on a load and as I drive just out of the blue it dies. Sometimes only a few miles other times I can go several hundred. All gauges still work the only thing that stops working is the cruise control. Most time turn key off and back on trucks starts up right away other times I have to stop and wait a few min sometimes up to 10 before it will start again.

 

Update
Ran truck yesterday loaded it died only three times about 90 miles down the road then ran great all day.
today I went 150 miles then it spit and sputtered then ran with it shaking the truck real bad with fuel added smoothed out coasting and lost most pulling power pushed in clutch turned off key then back on and started engine ran great. dash Code was 35 only.
Another 80+ miles and chugged three four time in row but did not die two more miles engine Died this went on off and on about 130 miles total times dieing around ten then ran about 100 miles smooth. Chugged twice the last 5 miles back to the house.
I have noticed that it acted up most times at the start of hills just as extra fuel starts to be added to make the climb after a long or steep down hill where no throttle was used or shortly after big bumps.

Thanks for any suggestions