so I have a 87 Camaro LT with the 305 TBI. 40,000 original miles the problem was that it would knock around 1500 rpm if I was on the interstate going uphill while in overdrive if I shifted back down to drive it would run fine. I decided to replace the spark plugs on it but that made it the idle worse. I thought one of the wires may have just fowled while moving them around so I decide to replace the wires the next day and now the idle is even worse and it wants to cut out at a stop and instead of knocking on the interstate now it jumps rpms like the fuel is cutting out. I'm stumped at the moment the car is stock on the engine I'm just trying to get it running right any advice? I've checked the timing each time and its stayed at 0 TDC

 

Your post would be easier to read if you used capitalization, punctuation, and spacing like you were taught in elementary school.

Defective spark plug--improper gap, cracked porcelain, etc.
Defective spark plug wire including the boot at the end
Mis-routed spark plug wire. Wire goes to incorrect plug, wire too close to computer sensor wires, wire routed too close to exhaust or sharp edges.