Yes absolutley it still does it

 

sounds to me like the injectors arent giving you a good spray pattern... being that it is about the only thing you cant really test then i would give it a go... what sux is its a 500 buck part to replace if it isnt the problem... another option would be to check your alternator and engne ground... it may sound weird but i have seen weirder on these vehicles... i bet its the poppet injectors though... i highly recomend the mpfi upgrade... i did it to my truck after the motor swap and with all the issues i had it was one that was well worth the money... cost the same as stock parts but wont fail in 100k... after replacing every sensor and pump on my truck it runs like a 2010.. lol..

 

You can certainly check the spray pattern of the injectors. It is pretty labor intensive though and is easier if you have a full feature, bi-directional scan tool, but it is not impossible.

Stuck or dirty poppet nozzles are not outside the realm of possibilities in these trucks. I would try a professional injector cleaning.

 

Thanks for the new input guys. Luckly I found a whole injection system off of a 1999 blazer with 37000 mi. for $50 I git real lucky the truck was totaled so the owner let me get the parts for nothing as long as I pulled them. So needless to say i'm gonna go get the parts this weekend try them and I'll let you guys no the results. Thanks again to all you guys that have shared your knowledge and input with me thru all of this.

 

Can't beat free. Hopefully it works out for you.

 

OK guys today I put in the new injector assembly put it all back together took it for a test drive and guess what..... IT STILL HAS THE PROBLEM!!!!!!! UUUGGHHHH Now I'm back to square 1.

 

After the vehicle sets overnight, before you start it, connect a scan tool and check the Engine Coolant Temperature, (ECT) sensor and the Inlet Air Temperature, (IAT) sensor. They should both indicate the same temperature.

 

Just curious....but how will this help me?

 

The PCM uses both of these when adjusting fuel mixture.

 

zmann6988-
For what it is worth. I had a stumble like you describe after replacing my intake manifold gaskets. Couldn't figure out why everything buttoned up like it was supposed to-then it starts throwing a P0300 Random misfire. Replaced all the same things you did. No luck. 2 months later as I worked it off and on-I literally stumbled across my answer-I had broken the locking tab on the Fuel Injector Connector. No problem I had thought as it still had 4 little tabs that held it in place. While feeling around the engine while running, I put pressure on the cap. Engine smoothed out immediately. Let off-it stumbled. Local ACDELCO said it was a dealer only part-so I found one off a wreck. Problem solved. Maybe it is a loose connection in your fuel injector connector.