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I suspect that the ecu is not seeing a tach signal, so it doesn't inject fuel. Test for a tach signal at the ecu while cranking. Check wires from coil - to ecu. You stated that there is no movement from tach while cranking, right? Get the fwm download and look at the fuel system wiring in the mpi section in vol 1. Trace the wires from coil- to tach and ecu. Pay special attention to the gizmos on the coil bracket besides the coil, and follow the tests for the power transistor as well. The gizmos on the coil bracket condition the tach signal for the tach instrument, and their wire insulation gets very brittle and if they crack, vibration breaks the wire via fatigue at the crack.

Do you have spark with the rebuilt ecu?


Thanks for the tips fasteddy. To answer your questions, I see no movement on the tachometer while cranking. I HAD spark when I first started troubleshooting, but no spark now, even with the rebuilt ECU (which is giving a "good" code now).

I smell fuel at the tailpipe now. I don't THINK I did at first. Would I smell fuel at the tailpipe if ecu was not injecting fuel?

Visual inspection of components in that ignition pathway doesn't show anything suspicious-looking. Will scrutinize a little more and get the multimeter out.

OK, still at work...will post more tonight.

1991 Montero LS (LWB) 3.0L V6 Stock 205K Miles