before I'd suspect timing chain I'd guess dist. gear - one way to check chain for slack, with the dist. cap off rotate the crank pulley back and forth slowly and look for hesitation in rotor movement
A very minimal amount of hesitation movement I would suspect dist gear
Usually in my experiance major hesitation is needed for a chain is to be suspected
This test is not 100% accurate but a good base to start with

 

yeah im gonna go check it out, i was just gonna pull the distributor and rule it either the problem or out

 

no hesitation between crank and distributor rotor

 

Timing chain not the problem.

 

there is the tdc mark on the crank, i rolled it and now i cant find it

 

where is it sorry typo

 

one of my friends had the 03 silverado with the 4.3 and she had a stripped dist gear. ended up changing everything out before they figured it out

 

That's exactly why we're helping you diagnose the problem
There are two marks on the dampener, see post #5.


Before you remove the distributor: use a socket & ratchet and rotate the crankshaft until the dampener marks are aligned with the index marks on the timing cover, AND the rotor is pointed near the "6", (having the crank lined up is more important). While the distributor is removed, DO NOT move the crankshaft, or activate the starter, or you'll create more work for yourself.

 

scratch that, the guy that put it TDC used the wrong mark on the dampener so my truck is dead nuts time. so i have spark to all holes, 55 psi fuel pressure at the schreder valve and dead nuts time. cranks and backfires out the throttle body

 

55psi is too low. Find out where the problem is:
https://blazerforum.com/forum/2nd-ge...eakdown-88305/