hi again

I have a 2001 blazer lt 4wd 4.3 auto

ok so here's the scoop: I changed the radiator about 2 or 3 months ago now as the plastic tank on the drivers side had ruptured and spewed antifreeze everywhere. anywho prior to this I had noticed that the speedo would bounce around I ignored it for a while as I had switched my primary vehicle well I had thot it was the vss I swapped it no change but the primary reason I am posting this is the blazer will start and run in idle position all day when I try to "drive" as it is difficult with no speedo it will run a short distance then stall when in gear at random intervals im thinking elec. issue but im not sure btw it has a new Delphi fuel pump a new filter that was rigged in no leaks anywhere that I noticed. Spark is good as it bit me when I tested the coil lol.
what id like to know is what caused the speedo drop out and is it causing the blazer to stall out

 

My first suspicion would be the vehicle speed sensor. Do some research about the VSS here on the Forum and see if anything matches your situation.

 

I agree it does sound very much like the speed sensor is playing up.

 

thanks for the help guys i did find part of the problem it was stalling due to the o2 sensor reading had dropped out so the pcm couldn't enter closed loop mode when the block warmed up.
I solved that isuue by replacing the 20 amp fuse labeled oxysen
i have not been able to test the speedo issue as the blazer is currently stuck in my backyard