Sounds like similar symptoms to what I had. Crank, no start, intermittent backfire. Vehicle ran fine one day, next day would not start with the described symptoms and very damp humid weather. Checked and replaced some of the things you did. Replaced cap & rotor and started right up. Pretty common problem with the 4.3 Vortec.

 

Thanks for the input fruitkake! Cap and rotor are still under warranty! i will go crazy if that fixes the problem lol

 

New cap and rotor didnt work. Thanks anyways

 

Just a thought....When my 97' was missing and backfiring intermittently, I changed everything from cap to ECM to injector spider, the list goes on and on......in the end turned out I had a burnt valve. $2 grand later she's running like a champ.

 

Hey all! I just found TDC during the compression stroke on the #1 cylinder for the no start blazer, and the distributor points just ahead of the "6" mark on the distributor. Close to the #6 cylinder pin on the cap. Does this mean timing has jumped?

 

Are the timing marks (yes plural) on the balancer aligned with the appropriate features on the front of the motor? The #1 cylinder will be just off TDC when the marks are aligned properly. If the answer to the above question is yes, then my answer to your question would be yes.

 

All lined according to the timing thread and how you discribed. Really, what else can it be? Other than a broken crank (which I know isnt broken). Everything checks. It must be the mechanical timing in the engine. Hayes manual seems pretty precise in the procedure..

 

Does the Haynes manual (junk IMO) follow the exact steps listed in the EDI Engine Timing thread?

There have been a few members that have had the outer ring of the balancer rotate on them.

If the timing chain were to have skipped, the distributor wouldn't line up right. But if you have had it out at all and reset the position, you might not be able to tell any longer.

Have you checked out either of these threads:
Engine Cranks But Does Not Run
No-Start - Engine Cranks OK - Ignition System Diagnosis

 

Yup.
The write up on how to remove the timing chain in the haynes manual to be excact. And thatd be stupid to take the distributor out, for that reason.. unless i marked it before removal. Wouldnt want to reset it like you said in the previous thread either. I can't wait to see this timing chain, it must be loose as a goose. Harvester of Sarrow by Metallica explains my blazer. I'll keep posting!

 

One thought, if the CKP sensor isn't in sequence with the CMP sensor wont the computer send a DTC P1345? Wouldn't that code would make sence if the timing chain did skip a tooth or two? No codes appear on my scanner. Does anyone have experience with this trouble code due to the timing chain?