About a month or two my truck shut down going down the highway. Gave no warning just shut down. I had it towed to garage, they said the alternator was running hot. We had to replace the computer cuss that was fried. we put a new alternator in it and everything was fine. Started up great! Drove it down the road and started to pick up speed. got to about 40 and the truck started bucking and check engine light comes on. Everytime you get the rpm up to 2 itys starts bucket and will shut down. Anyone have and clue?? Waste gate, fuel injector etc etc.. Please someone help!!! Divorce has caused funds to be tight!

 

Moved to the 7.3 forum for better assistance.

 

Did you have the codes pulled?

 

Did they check all wiring connections at battery's and grounds. Sounds like a possible high amperage draw.Just a WAG here but easy to check connections & its free. A short to ground can also cause this. This happened to me with a pos. battery cable on my old chevy pickup truck. The cable was touching the manifold & after it ran awhile the manifold heated up & melted the insulation. Truck would start bucking like a wild mule shortly after. Gauges also went crazy. Good Luck

 

First thing to do is get the codes read. That will point you(and us) in the right direction.

 

The other free check would be to pull the valve covers and check UVCH. It may cost you as little as 50 cents to fix if nothing is fried. Check the harness at the DS VC for chaffing, and check under the steering column for chaffing. Post your location so we can see if anyone near you has AutoE to pull the codes. I wonder what made the shop think your PCM was fried.

 

OP, where are you located? Maybe someone here is close by and can help.