1995 Turbo diesel 6.5 does not have the power and under acelration chek engine comes on?

 

Welcome to the site.

Tony

 

Probable vacuum pump needs replacing changed mine and performance went up and check engine light stopped coming on

 

Get codes checked and post them here.
Boost solenoids fail.
Vac lines rot.
Vac pumps fail.
Boost sensors fail.
Collapsed exhaust crossover internally.
Plugged soot trap in exhaust.
Plugged air filter.
Air leak in fuel lines.
Plugged sending unit tank sock.
Plugged fuel filter.
Worn out IP.
Worn out injectors.
Dead lift pump.

Take your pick-we need more info.
Post #2 of this thread has a diagnostic checklist link and instructions:
https://www.dieselbombers.com/chevy-...ml#post1052260