I have the same problem, it doesn't happen all the time but it is the same I know by reading your description and watching the videos. I took it to a shop a month or so ago i know the guy he's pretty good. I just asked him to try and diagnose it. I told him i had already replaced all ignition parts(plugs, wire,cap,rotor,coil ect). He checked some stuff in the shop then test drove with scan tool with live data and said its fuel related, now dont quote me but i thought he said something about the trim being off. He said to replace the fuel pump. Sense it only does it from time to time i haven't gotten around to changing the pump yet, I don't know if i will fix the problem but i figure with just over 100k its preventative at this point. I hope to change it within the month, I'll let ya know if it fixes the problem. O and i did already change the fuel filter it didnt make a difference.

 

Just had the fuel pump done a few months ago, plus the mechanic double checked the pressure when I brought it back.

 

Well, the drive to work went smooth, so I'm thinking this is fixed thank God!

Now to start figuring out the other issues... specifically why the passenger seat won't stay locked in position (forward-backward) unless it's pushed all the way back.

 

it's not your fuel pump, I have a new bosch one and it still does it.

 

I've learned something very important from all of this... ONLY USE AC DELCO ON BLAZERS!!!

 

Bosch has a lifetime warranty on their fuel pumps unlike ac delco, so I'll get a free one if it ever goes out.

 

Random, The odd pattern can be caused by having the CMP Retard out of spec (spec is 0 degrees). This needs to be set using a scan tool capable of displaying the value from the PCM. Monitor the PCM data while moving the distributor in its bore (note, not turning the distributor per-say, just pushing it around in the bore; there is enough room for ~15 degrees of change in CMP Retard).

CMP Retard being excessive can also cause excessive wear on the distributor drive gear.

I'm reminded of Tommy Boy when people say things like that! "Crazy glue sniffer". LMAO!!

In the end, if you have the time to keep swapping them out, good for you.

 

lol if it's life time warranted the idea was it shouldn't go out cause it wouldn't be cost efficient for bosch. It better never go out, i'll be furious I hate fuel pumps haha

 

From what I am seeing though, the Delco parts are the only ones that seem to not consistently go out though.

 

ya agreed, if you have the money, from my person experience delco parts seem to be the way to go. (in terms of electrical components)