92 GMC 350 TBI, cuts out and seems to misfire?

[Kevin E]

I have a 92 GMC P/U with TBI, it starts up and idles with no problem but when I go to give it gas it cuts out, sputters, and almost dies then it will finally get RPM and go fine, also when I slow down to go around a corner in like a parking lot it sputters and almost dies too it also has a really strong exhaust smell. When I am speeding up sometimes it also cuts out every few seconds why on the gas. I have replaced the cap and rotor, plugs, wires, and throttle controller. The motor is somewhat new it only has about 35,000 miles on it and has never ran too great since was replaced. We did not replace anything but the block and water pump so all the sensors and everything are still stock. Any ideas of what may be causing this? Once I am up the speed the motor seems to have normal power for a 350 TBI. Any help would be appreciated, thanks in advance.