96 Blazer, problem starting/running

The poppet valves went bad on this vehicle, and i replaced the spider. after i replaced the spider it started up and ran fine for about 15 seconds. Then it started backfiring through the intake and died.

It will turn over just fine, and it will start. after running for a few seconds, it starts backfiring through the intake, and dies.

fuel pressure is good, there are no vacuum leaks...i can't figure out what the issue is. any ideas?

What is the fuel pressure with the pump running and the engine off? After the pump shuts off, does the pressure remain above 55psi?

What is the fuel pressure with the pump running and the engine off? After the pump shuts off, does the pressure remain above 55psi?

62psi with the pump running, and it stays above 60 with the key off.

upon further inspection, the coil is putting out a dull yellow/orange spark. the battery is fully charged. any ideas?

Are you sure you have the plug wires on right ?

Check your ICM and your coil. Both should be replaced at the same time if one or the other is bad. How long has it been since you replaced your cap, rotor, wires, and plugs?

Check your ICM and your coil. Both should be replaced at the same time if one or the other is bad. How long has it been since you replaced your cap, rotor, wires, and plugs?

cap, rotor, plugs, and wires have been replaced recently. i'll check the coil and icm. could corrosion in the wiring cause an orange spark?

High resistance is what causes the orange spark, and yes, corrosion will cause high resistance.

i replaced the rotor button with an ac delco rotor button, and the blazer will now start up and run.

however, the check engine light flashes, and it is backfiring. the trouble code my scan tool reads is 0300, "random misfire detected."

any advice?

still having the same issue. if the internets have failed me, i must take it to a mechanic.

P0300 is most often caused by secondary ignition faults. Secondary ignition includes spark plugs, distributor cap, rotor, spark plug wires and the ignition coil. Use a spray bottle with water and put a mist over the parts with the engine running when it's dark out. Watch for stray sparks.

btw, the issue was a blown intake gasket olololol!!!