350 won't idle

i have a '91 gmc fullsize and it won't idle. it's a 350 with throttle body. checked timing and chain, changed plugs/wires, checked firing order, etc....it revs up fine and comes back to idle, then dies. any suggestions? thanks.

replacing your Throttle Position Sensor should do the trick. $31.99 at Autozone, part number TPS112. Had the same problem a while back and went through about every sensor there was, and this is the one that was bad. Its located Under hood, center, upper engine area, center of intake manifold, mounted on passenger side of throttle body unit.hope this helps you out