Yeah a guy w/o a clue. Hello everybody! I've done extensive reading through this forum, and I was impressed.
Anyway I'm here to sound you out. I have a reoccuring DTC PO300, in that it seems to come and go. I recently completely OH'd the 4.3 which ran good for a while then developed a miss and a DTC warning. Took it to Auto Zone, they scanned it and told me it was almost $200 in sensors. One of them was the camshaft position sensor. Hmmm, that's on the distributor, that's driven by the camshaft.
I felt it was a false scan due to me putting the dist. in a tooth off. I made the adjustment, started it up, no more miss, no more check engine light, all's well...for a couple of months. The miss came back. I bought the most expensive scan tool from F&F, hooked it up, it gave me a PO300 MULTIPLE RANDOM MISFIRE. Yeah, really? I used an old timing light to locate the misfire. Every cylinder was missing, tried it on the coil, it was missing too. Changed the coil...problem solved all's well, for a while. It's baaaack.
So what I'd like to know is what is sending a signal to the coil telling it to intermittently throw juice/ or what is ahead of the coil and making it fry out?
I'm changing all my ignition parts to AC today. Thanks to anyone and everybody for having me here.

 

If you haven't already, read through this thread : P0300 Explained

And welcome!

 

No, I didn't see that one. Very informative. Now I just need a day to wrap my head around it all. The cap and rotor do look like they have spark trails on them. Thanks tons!!

 

Thank Kyle, that was his contribution (among many).

 

I'm sorry I took so long but I got a little busy this week. If you could please pass my thanks along to Kyle for me I'd appreciate it. Otherwise let me know how to get around this site more fluently so I may reach him personally, thanks!
I changed the cap and rotor with AC Delco and immediately it ran better for about two days. It is missing again but, only when just over idle, say about 1000 to 1500 rpm. Over 1500 rpm we still have a marked improvement compared to earlier.

 

Welcome to the forum from Canada!
Kyle is under the user name "swardlkk" If you do a quick search you'll be able to find him.

 

Swartlkk

 

Thank you Sisk. I found him with a "t" and thanked him. I hope to figure out how to make kool pictures out of my plain old photos like you guys one day, but really just trying to navigate through this world and fix mama's '99 blazer is a bit of a task right now. Thanks for everything.