Hello,

I bought a 1999 Blazer 4.3 ended up pulling heads as one was cracked., So I did every thing from Head gasket up. Also replaced Cap, rotor, plugs, .and wires. Fired rite up and ran well until service engine light came on. Pulled codes P0300 and P0304. I pulled distributor back out and checked gears and looks good. I reset light ran it again and now light solid at idle and blinks driving it. I pulled codes again. This time I get P0300 and P0305. I'm wondering if issue with spider injectors? Going to check fuel pressure today. I didn't do that as previous owner said they just had fuel pump replaced.

Any help be greatly appreciate

 

The previous owner likely used cheap gasoline, Try some Techron Complete or Seafoam in the tank, then take it out for an "Italian" test drive on some road where there won't be any Fuzz. Punch it to the floorboard., and rev that pickup out to the max.

 

Yes done that already, I found the problem was in the that powers injectors was loose. I accidently bumped it and engine stalled. Since I corrected that problem. I've driven over 100 miles and been running good and no service. Thanks for the reply