my 4.3l hesatates when I give her some. I just put new plugs, wires, cap and button and noticed the guts of the dist. was a little rusty. could my problem be in this area? Is it time to replace the dist.? Is it possible to take the thing apart and clean it up?

thanks  

Same cold or hot?  

I had some time to play with tis thing yesterday,I replaced the engine temp sensor like you said and still had the same problem. I checked and adjust'd the timeing. Also put timeing light on every plug wire and watched flash patterns. Deceided to pull one of the new plugs and found it carbon foul'd. Pull'd all plugs and cleaned.It still hesatates and black smoke at take off. Should I try a hotter burning plug? Once i wind it up it will go allright untill the r.p.m.'s come down. It's like its running a little to rich on take off's.And i don't know how to adjust for that.  

check to make sure the plugs are gaped right  

Have you checked the MAP sensor and TPS? Also when you checked timing did you disconnect the electronic advance wire before timing it?  

Well guys, I wasnt sure on the plug gap so I checked them. They were out so i regapped them and had to clean them again.I've got ac delco cr43ts plugs in it. I still have the same problem after all that. Yup, the MAP, TPS and egr noid and now engine temp sensor are new. And I did pull the spark advance wire at the firewall and set timeing at 0 degrees.The only things i can think of are maybe the O2 sensor or hotter plugs?   thanks guys  

Try about 8 BTDC and 89 octane fuel. You might check injector pressure too as it should be about 9.5 to 10 PSI.  

Tell me if this makes any sence? Some how my fuel tank is building preasure (bad cap?) and sending fuel up the vent tube to the canister and then up the vacuum line to the throttle body. I removed vacuum line and plugged, removed tank cap, replaced all the plugs again. Also removed the muffler to releave any backpresure issues (it looked kind of shadey anyways). All this seems to have cured the problem.............weird!