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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15201
Experience:  GM Grand Master Technician 2007. 14 years experience.
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I have a 1999 blazer 4.3 vortex. I replaced cap,rotor,plugs

Customer Question

I have a 1999 blazer 4.3 vortex. I replaced cap,rotor,plugs and wires. Still getting po300 random misfire code. Any suggestions?
Submitted: 1 year ago.
Category: Chevy
Expert:  Chris (aka-Moose) replied 1 year ago.

Welcome, I'm Chris (aka Moose). Experts aren't employees / agents of Just Answer. We are independent service providers using the Site to sell their Expert knowledge to Customers. I strive to provide EXCELLENT 5 STAR service, let me know what's needed from me so your pleased.

  1. Does it physically misfire?
  2. Can you feel this misfire?
  3. If it is misfiring does it occur most with the engine cold, hot, idle, or driving?
Customer: replied 1 year ago.
The engine run a little rough while idling at a stop or in park. When driving it seems to run ok. Replaced some vacuum lines. The exhaust coming out of pipe looks like a little smoky.
Expert:  Chris (aka-Moose) replied 1 year ago.

Can you check the cam retard offset?

Can you compare the Bank 1 Sensor 1 (B1S1) and Bank 2 Sensor 1 (B2S1) readings?

Are you able to check the fuel pressure and fuel trims?