I have a 94 blazer and I was driving and that tach started jumping and the truck started bucking and hesitating all of a sudden, I couldn't go fast at all. I changed the plugs cleaned the injectors, cleaned the filter and changed the ignition coil, the wires and distributor cap and rotor button are two months old, it seem like when I start it up and go around the block I have full power, but after about 20 seconds of driving it start jumping and bucking and even backfired. Someone please help me out

 

what size motor do you have if its the 4.3 vortec like mine was i had the same problem about a year ago and i found two problems one was a cracked fuel line under the plenmom and it was feeding to much fuel running to the motor the other was a mass air flow sensor after that my blazer ran great try them if not the problem sorry i couldnt help...

 

Are there any codes?

 

ok i really need help my first child will be born in 4 weeks and my truck is acting funny. i was driving my truck and it started to get sluggish, the next thing i know it started to hesitate when i slow down, when i start to move again, it does it also, when i hold the gas down some the engine starts jumping and bucking (while in park). i just changed the spark plugs wires and also the ignition control module yesterday. i changed the distributer cap and rotor buton, and ignition coil about 4 months ago, please help me