Several days ago I replaced all four injectors because one was leaking badly (gasoline running down engine). I used Python injectors because that's what my parts store could supply four of. On starting the engine ran well for about 30 seconds then stuttered, coughed, and drove horribly.

While trying to find the problem, I wiggled some of the wires that control the injectors and the engine stalled; most of the wires had breaks in insulation, so I spliced in good wire from down low in the harness, where the wires are good. On starting the stuttering, coughing, etc. were not improved.

Today I got out my Chilton's book and went looking for vacuum/wiring problems. Nothing I did affected the way the engine ran. Finally I tried pinching the "fuel return to tank" line. The engine smoothed out, and the car was drivable. Tomorrow I'll start the engine, get it warmed up a bit by feathering the throttle, clamp off the fuel return line with vice-grips, and drive to work.

Looking past my immediate need to get to work, I need to solve this problem correctly. Does anyone know what the problem is, and how to repair it?

Thanks, Scott