My truck losses power an goes to safe mode
Until I turn off the key an restart the engine I am able to accelerate until
I reach up to 50 miles hr
Then goes back to safe mode

 

Welcome to FTE!

Can you describe the safe mode? There's some conditions that can seem like that, but these trucks don't have an official programmed safe mode.

My first thought is perhaps the screens in the fuel tank are clogged. In that case the amount of fuel that gets thru can be enough to idle and drive under low load, but asking for more fuel than it can provide will cause a stumble and no power. You can temporarily clean the screens by removing the fuel line from the inlet of the fuel pump and blowing back to the tank with some compressed air. Not a ton a pressure, SWAG I'd recommend 50 psi, and have the fuel cap off. A pic of the clip that holds the fuel line on is below.

Also, do you have more tan 1/4 tank of fuel? Does it smoke when this happens? Got a check engine light, or a way to pull codes?

 

My mechanic said number 8 cyl has 100 psi compression
While my others have 375
Can my computer be the problem

 

If you have 1 hole with only 100 PSI of compression it sounds like you have base engine problems.

 

Describe your safe mode with more detail.

For the compression issue, the computer won't be the cause of that.

 

Did your Mechanic pull the valve cover and do a compression test? That low compression would cause a miss likely with smoke but not what you have described.

This really sounds like a fuel issue (pressure).