Hello, I have a94 Chevy S10 V6 4.3 vin Z, 2w, 5 speed manual trans and I have had the same issue in the past. I can't recall if you mention that the check engine light was on or not, but you may want to check the Oxygen Sensor.
If I remember correctly, it is located on the driver side mid way way down the exhaust near the main frame of the the truck.
Good luck,
Aileen