Nissan Repair: Rough Idle, poor gas mileage, vacuum lines

Question
My daughters 92 Stanza (recent purchase, 125,000 miles)has a rough idle and the engine growls when driving. She also complains of poor gas mileage. I changed the spark plugs(ngk), ignition wires, cap, rotor, distributor(dist.was leaking oil internaly), Set timing to 15 BTD. pcv, air filter and fuel filter.Checked vacuum lines, they seem to be ok. Used a bottle of Techron fuel injector cleaner. Still the same. Any suggestions would be greatly appreciated.

Answer
Check the static timing to see if the timing belt is on zero.  Run the engine up to zero on the balancer and then check the number one intake to see that it is just about to open.  If it is not the static timing is off.  Also, check the intake hose to see that it is not damaged and leaking.