My blazer jerks

It seems to do good going thru gears but when goes in to overdrive and is picking up speed it jerks on me i can floor it and does fine but when going up hill in od it jerks. this does not happen all the time not until a few days ago.

also when starts up smokes alot then subsides then if sits still for a few starts smoking and after take off smokes alot for a about a mile

any help and cost to repair is appreciated

thanks Keith Wood

92 s-10 chevy blazer 4wd with fuel injection

sounds like my 91 if u gun it it will like lurch back likes it gonna take off then u hear the engine kickin then u take off for the smoke i dont know i get that alot even in the summer whens it 90 out

It seems to do good going thru gears but when goes in to overdrive and is picking up speed it jerks on me i can floor it and does fine but when going up hill in od it jerks. this does not happen all the time not until a few days ago.

also when starts up smokes alot then subsides then if sits still for a few starts smoking and after take off smokes alot for a about a mile

any help and cost to repair is appreciated

thanks Keith Wood

92 s-10 chevy blazer 4wd with fuel injection

When was the last time you did a complete tune-up? Aslo, the fuel pressure should be checked and, I'm assuming here that it is a 4.3L, the CPI unit should be checked for washing. The smoke you have on start up is more than likely the valve seals.