1989 chevy blazer full size rough idle

SOURCE: 1989 Cavalier Z24 3.1 rough idle and hesitation

its just white cuz i too the cat off..

cuz i thought my proble could have been to do with the cat...

cuz i lost power driving up hills and on highways now it just will start the die right away

or start and idle really bad...

any ideas???

i was thinking crank sensor.. or injectors

SOURCE: 95 GMC Jimmy 4.3l W vin rough idle

My problem was solved when I repaired my 4 wd activation dash switch. The switch was contacting on 2WD & 4HI at the same time. The front differential activation is vacuum activated possibly creating a tug of war that didn't actually engage it but drained off vacuum from the engine? A theory at best but stumbbled across it because I knew the switch wasn't working properly I repaired it and low and behold rough idle disappeared and all is good for 3 weeks running.

SOURCE: 1989 Cavalier Z24 3.1 rough idle and hesitation

I had the same problem with my Z when i had it. But it worked when i just left the little hose off of the EGR valve.

SOURCE: 1987 chevy s10 2.5l tbi will not start. changed

That eliminates the crankshaft and camshaft position sensors. Have you checked the fuel injector itself for an open winding or stuck valve plunger? There should not be a steady 12 volts to the injector--if good injector, it would be spraying fuel steadily into the throttle body. But at least the engine should try to run if poorly. Take the injector out, dry it off with air, and intermittently apply 12 volts to one terminal while grounding the other. You should hear a click from inside every time you touch 12 volts. If not, replace it. If it does, it may be plugged with debris. Try blowing through it in reverse with compressed air.

SOURCE: 1992 Chevy Silverado idles rough why?

Check your MAP and TP sensors. Your throttle body may be having trouble determining position and is compensating by adjusting RPMs.