1988 GMC C2500 • 216,000 miles

I have an 88 GMC Sierra with a 4.3L V6 w/ EFI, 216,000 miles on it. I just bought it from a guy that I anticipate didn't know much about the truck. The truck starts just fine, but after a short period of idling fairly well, the idle kicks down and will stall. As well, when I try to drive it there is little to no power when I try to accelerate. It actually does better briefly when I let off the gas pedal. And if I come to a stop sign I have to shut the truck down and restart it just to restore enough power to accelerate. I've changed the fuel filter and put some injector cleaner in the tank to possibly eliminate those two issues. What is the problem. Please?
November 5, 2012.

Scan for codes, and check tosee if gasket is blown undre tbi unit, spray choke cleanr there if rpm changes it needs to be looked at. See if vacuum hose going to map sensor on firewall is soft it may be sucking together knocking themap out. Finally cheick vaacuum at idle if 15" or below suspect clogged converter.

Nov 5, 2012.
Alright I will check those things tonight. Thank you.

Nov 5, 2012.