81 22r won't idle
 

well today I went to the bank and my truck was driveing fine, but as I left it wouldn't idle not oin neutral or in gear, eveytime I let off the gas the engine died. Any ideas on what my problem is? Maybe new plugs and wires?

I just checked my truck, and it seems.im dangerousely low on oil. I think that may be my problem, any advice would be greatly appreciated.