I had a very small crack in the porcelain part of my spark plug that was arcing and "clicking" against the head, giving me a little miss in the engine. May want to check the plugs. It was a pretty significant clicking.

 

I immediately knew this would happen when I posted it; alas it was too late. I believe I was attempting to say "misfiring"

 

Thanks for the tip, I know the plugs are old - I'll be replacing all the plugs when I do the LIM gaskets. I have all of the parts to do it, now I just need the time. I'll be replacing the cap and rotor tomorrow and subsequently follow through on this post.

 

Good call! I went to replace the parts today and they seemed worn on the inside of the cap and the edges of the rotor. I checked the old parts, which I had saved, and they had similar wear. So, instead of replacing the aftermarket parts with the new ones, and having the same thing happen, I'm getting a new distributor. I've read about the bushings wearing out on distributors, and I'm guessing that's the case here.

Wear on the edges of the rotor, side view
Wear on the edges of the rotor, top view
Wear on the edges of the rotor, side view
Inside of the distributor cap
Wear on one of the brass pins in the cap, and against the edge of the cap


When I replace the distributor, I'll follow up on this post with the results.

 

I don't think that's wear on brass but a manufactured flat surface, but we may be talking about two different spots on the brass. It looks very clean to me. On mine, there is a lot of corrosion or scaling caused by ozone. It happens pretty quickly, so yours is remarkable clean from my experience.

It seems pretty obvious that the rotor was rubbing on the cap, In the last picture it looks like you can see where it cut a grove in the tunnel where the screw goes. That would indicate to me that the cap or the rotor may not have been on tight and that would certainly cause a problem with a miss. I suppose that a worn bushing if bad enough could have also allowed things to move around enough to cause the problem. This fits in with your description of the clicking. After a while, it wore down enough material so that there wasn't anymore interference. If the bushing is bad, you should feel some lateral movement if you rock the rotor from side to side.

I bought a aluminum distributor for about $40 off of Amazon. It came with a new cap and rotor. It seems to work just fine. Here's a link: Price appears to have gone up $10 since I got mine.

 

Looks like the same Chinese distributor that Skip White used to sell. I have one and it's been fine for several years, but I switched my original Delco cam sensor over and put a Delco Cap/Rotor on it! You can search for Vortec V6 Distributor in Amazon and come up with them for under $40. Ones I remember have shiny machining on lower distributor body. Don't forget to check/set Cam Sensor Retard.

 

I found a remanufactured Delco one at Auto Zone for 51 bucks. There's definitely a lot of play in the rotor if I move it back and forth. I'll be dropping that one in as soon as I stop working from sun up until sundown!

 

The Blazer was running terribly up until I replaced the whole distributor, and I found out part of the reason why:

cheap Chinese garbage rotor broke after 2 weeks
Also, the old distributor's bushings were non-existent, I could effortlessly move the rotor back and forth at least a quarter of an inch. I replaced the distributor with a remanufactured Delco, and replaced the cap and rotor with delco parts, and it runs perfectly now.

I took the advice of a previous post on the forum and made marks on my old distributor and my new distributor, and matching up the position was a lot easier. I'm no mechanic, and the whole process took me about 15-20 minutes.

Next step: LIM gaskets!

 

Keep us updated.

I'm a huge OE fan for anything electronic regardless of brand. Much cheaper and less stressful in the long run IMO.

LIM's are a fun job. Give yourself a weekend or so.

 

Here's a pretty good guide on doing the LIMs. My experience was one of it taking a good amount of time to take everything off so I could get at the LIM gaskets.

How To Replace Intake Manifold Gaskets On A GMC Jimmy 4.3 Liter V6 To Fix A Coolant Leak - GM Truck Engine Repairs

Two things I wish I had done differently:
1) Read more closely the part of the directions that identify all of the bolts and nuts that you need to remove/loosen to slide the AC/PS bracket forward.
2) Cut the heads off of four of the old LIM bolts and install them temporarily and use them as guide pins while lowering the LIM.

Also I saw a post recently where someone claimed that the RTV sealant provided with the Fel-Pro kit with the upgraded LIM gaskets is not as good as the stuff you can get at the auto parts stores.

Good Luck!