GM-GMC: poss. fuel prob?, auto parts stores, timing error

Question
My question is for a 1993 sierra 4.3l.It starts and runs fine, when I let out the clutch (in any gear) I have to rev it way high to avoid bucking. It has stalled twice and won't restart unless i let it sit for an hour or so. I have changed to fuel filter cleaned the TBI, changed the plugs and added fuel treatment. I am vehicularly retarded so any response should be at that level. Thank you in advance for your help.
Dan

Answer
This one is way outside my experience.

Your problem is either being caused by something in the ignition system (timing error or other defect), or you have a worn out clutch.

You should take the vehicle in and have its computer diagnostic codes read.  Many auto parts stores will do this for free if you do not want to take it to the dealer.