Sorry i'm still a complete newbie as this is my first manual car. When driving it, first and second gear works normal but when i shift from second to third, the third gear doesn't catch and the car goes to 1,000 rpm and feels like it's just in neutral when it's not. To fix shifting to third gear, I would shift from second to third (third gear not working at this point) and then I would have to go to neutral and then back to third gear, then it'll catch on and work.

What is happening that's causing this? How to fix?

 

Sounds like you're gonna have to open up your tranny. Probably need new synchros. Maybe even a new 3rd gear. Won't find out until you open it up..

 

B series transmissions are known for the third gear going out first. every now and then when i try to get on it it will grind into third so i know ill need to open mine soon. to compensate for this for the time being, just shift slowly and with lower rpm's into third and double clutch. it will continue to do this untill you get new syncros or a new 3rd gear. If youre in a pinch, use Gm's syncromesh to replace the current trans fluid. if it is indeed the syncro, this fluid will add more friction to it so it will work a little better for now. however higher friction= faster wearing, if you do this you WILL still need a replacement.

 

If it is not grinding when you try and shift into 3rd, it is unlikely a problem with the synchromesh, more likely the 3/4 gear shift fork is bent.

It can also be bent a shift rod or extension change rod or bushings related to the shift "linkage" [gear shift lever/shift rod/extension rod], I would check them first as transmission does not need to ne pulled for that. 94