Hey I have a 93 Blazer with the 4.3 Engine. It misfires bad and has no power. I put new plugs cap and rotor in it and doesn't run much better. Today I did the compression test and got these readings1) 127psi, (2) 130 psi (3) 120psi (4) 140psi (5) 130psi (6) 140psi. This engine has 158k on it and the body is in decent shape. I took the new plugs out and three were black (4,5,6) and three were not black (1,2,3). Am I looking at valve issues or could it be some major work. Is it fixable without a rebuild or do I throw a used engine in? Thank you for your time.

~Kenny

 

which engine do you have the CPI or TBI? Do a fuel pressure test, what are the reading with Key ON(not Started), and how long does it hold pressure after you turn the key off.

 

I have the CPI vin "w" engine. I don't believe its a fuel issue but it wouldn't hurt to make sure that has good pressure so I can save myself burning out a fuel pump. I was thinking after I posted earlier maybe I should check the timing and see if it all lines up. It sure seems like the valves aren't opening the time that they should be. Maybe the timing chain has jumped? What do you think

 

I think you ought to take a fuel pressure reading key on then key off and watch it. Report your results here and we'll try and help you. May not be it but you need to discount some things. Jerry