I've got a '94 S10 pickup. It's got the 4.3 vortec and a 5 speed trans. In stop-and-go traffic the more I shift the harder it is to get the clutch to engage and disengage. If I put my toe on the pedal and push it all the way to the floor, it still will inch forward if I'm not stepping on the brake. If I shut the engine off, it slips into gear quite easily, which brings me to ask, is there some sort of sensor on the trans that may be malfunctioning, and causing this condition? I'm getting tired of fighting this problem.

 

Your transmission is a NV3500, it has a hydraulic master cylinder with a slave cylinder that operates the clutch fork. First I would check the fluid level in the master cylinder and if it is low you can fill it with DOT3 brake fluid. If the fluid is OK then the next thing to check if the slave cylinder to make sure it operates correctly, if both of them are good the you might have to remove the transmission.

Since you have a 94 I figure it has a lot of miles on it. The NV3500 has a steel pivot shaft that the clutch fork rides on. I suspect that either the pivot shaft and or the clutch fork are worn badly not allowing the pressure plate not to fully disengage the clutch pressure plate from the flywheel.

The thumbnail is one that shows a pivot stud that is worn out.

 

The fluid levels are good, the transmission was rebuilt last summer, and I had the slave cylinder checked when this problem became obvious. As I said, it shifts fine when I'm in light to moderate traffic, it's only when I'm in stop & go jams that this problem rears it's ugly head. Once I shut the engine off, it shifts fine, that's why I suspect it's something electronic, i.e a sending switch or sensor that is the gremlin.