My Blazer miss real bad when it is cold but when it gets warm it seems to level off and runs fine.I have replaced the plugs,wires,cap,rotor, fuel filter with Delco parts, but it did not help. Sometime when i crank it while it is cold it runs find, but not often. A scan show that no 4 cyl is missing, what do i check? one person said it may be the intake gasket blown, i sprayed with carb cleaner to find leaks but nothing. Any suggestions what to look for or check?

 

pull the distributor out and check the condition of the drive gear. My truck was doing the same thing and I replaced the $45 gear and pow no miss.

 

Thanks, i will get that a try