I am new to the 6.5 Chevy diesels. After buying my first 94 Crewcab K3500 5speed stick, I went to Leroy Diesel and bought almost everything to bulletproof it. The truck starts and runs. However, after driving down the road a few miles it goes into what I would consider a limp mode. The truck being a stick shift I'm able to push the clutch and shut the truck down and re-fire it while going down the road it then drives normal again for quite some time. However, after a few miles, it will go into limp mode again the only code the truck has ever had was for the glow plugs. That has been resolved. No codes appear all gauges read properly. Any ideas would be greatly appreciated.