i found this on the internet when i was trying to fingure out my mixture probs with my tbi unit....

It pays to check the charging system sooner rather than later during difficult driveability diagnoses, then see if fixing it also solves the vehicle's driveability ills.

Fixing the charging system often solves a vehicles driveability woes. Way back in the late 1970s, a very wise instructor cautioned me that charging system failures could be the root cause of driveability symptoms. His advice helped me quickly solve some strange performance problems on Chrysler Lean Burn systems. During that era, friends who specialized in European EFI work heard the same advice from their Bosch instructors: Fix the charging system first!

MOTOR reader Nate Gratz, a technician in Reno, Nevada, recently gave me an example of how effective the charging-system-first philosophy can be. A 1987 Nissan Pathfinder equipped with the 3.0L V6 and throttle-body injection (TBI) came into the shop. It suffered from intermittent bucking, misfiring and stalling during heavy acceleration when the engine was hot. No trouble codes were set. After careful scope testing revealed that the injectors were shutting off for some reason, Gratz instinctively checked the injector wiring first. A fuel leak allowed gasoline to both damage the injector wiring and contaminate an injector harness connector.

After Gratz made the necessary repairs, the Pathfinder ran fine for more than a year. Then it came back with very similar symptoms. Not only were no codes stored, but scope testing showed more possible injector circuit trouble. Fig. 1 shows normal current flow on a Nissan TBI injector at idle. If you aren't familiar with this pattern, the ECM turns on the injector at A. Current should increase steadily until it reaches B. The slope of the line from A to B should be smooth and flat. Now compare this normal slope to the one in Fig. 2, which was captured at 2500 rpm. Injector current drops suddenly near the top of the slope, as if the injector was beginning to shut off.

Do you have the images it is referencing? Would be helpful to see.