why is my 1998 chevy blazer not accelerating and wont get up and go? on 1998 Chevrolet Blazer

I went up a hill and a white puff of smoke come out and its been surging ever since I have to let off gas so it will get up n go

Asked by for the 1998 Chevrolet Blazer
Have a mechanic install a fuel pressure test gauge, turn key on and note pressure reading, turn key off and pressure should hold., not drop off quickly!!! If pressure drops as soon as key is turned off,, then suspect fuel injection spider....under intake plenum. Pretty common failure on older cpi systems...