1996 Camaro 231 cu in (3.8 L) V6 4-speed automatic

After I put in new water pump, flushed radiator & reservoir and filled radiator with new antifreeze/water mix, my Camaro began to hesitate when accelerating from idle and when passing at 50 mph. Now it started to hesitate and chug going up hill. Car idles good and drives good on level surface at constant speed. I cannot find any vacuum lines, electrical wires, plug wires or anything that I might have knocked loose or damaged. A neighbor told me that it might be a leaking transmission vacuum line. What else might be causing the hesitation and chugging.

 

Vacuum hoses get brittle as they get old and may develop a leak by just touching them but they look good. You have to touch them all and move them around to find if one is cracked and leaking.