Fuel injection questions

TBI is easier to diagnose than MPFI since you can see the fuel spraying above the throttle plates. If your controller is like my Holley Pro-jection 2D, the injectors should spray in synch with the engine rpm. Holley uses the coil- signal, relying on the engine's ignition system to sense the crank. The factory Mopar system probably uses the raw crank signal instead. Regardless, that makes fuel pulsing linear with rpm, which is needed. Pro-jection then varies the spray "pulse width" with throttle position (TPS). The factory system probably uses manifold pressure (MAP) and temperature (IAT) instead, which is better. Pro-jection has 3 knobs for the user to "warp" the TPS effect with rpm. The factory probably uses a digital map for that. I agree that if it sprays continuously, the injector control wire is probably grounded (or transistor failed short). Just like an ignition coil, constant +12 V is applied to one side of the injector coil and the control transistor connects the other side to ground to turn on the coil. Many more details on the megasquirt site.

Worst-case, you could substitute another fuel controller just to get it driving. Holley's Commander 950 would be best. I bought an ECU alone for $150 off ebay. Easier and cheaper would be a Pro-jection box. I bought a spare one for $15 off ebay. The earliest "by MSD" boxes are easiest to wire since they use weather-pack connectors. Those are also more robust. The wimpy connector Holley put on later boxes is problematic (wires pull out). Megasquirt is an option, but more work and they aren't cheap (<$200), but there is excellent info and support. A GM box is another option. Check out Bill USN-1's Binder Planet site. Howell Engineering customizes GM boxes. One to avoid is MSD's early EFI box. They quickly fried the COM port, so MSD dropped it after 2 years and left customers hanging. It was an early version of Meany's BigStuff1 box, but nobody fixes them. Meany makes BigStuff3 EFI now for hard-core racers.