Ford 1972 Bronco TBI upgrade (1 Viewer)

[beaudog24]

I 'm at the tail end of installing a TBI system on my 1972 Bronco with a 302 engine. I got all my parts from a 1989 Chev Suburban with a 350 engine. I have a HEI distributer that was in my Bronco before I started this project. It has mechanical and vaccum advance so I locked down the mechanical advance and pluged the vaccum port. I'm using a GM 8 pin ignition module that plugs right in to the wiring harness I got from the Suburban. I hard wired from my magnetic pickup coil in my distributer to the 8 pin ignition module I mounted on the in side of my fender wall . I'm using 3 sensors oxygen, coolant temp, and map. I know Turbo city sells a system thats based on the the chev ECM and uses 3 sensors so I think I'm on the right track? Right now my rig starts and runs the problem I can't figure out is my timing, with the timing set control wire unpluged the brown wire with a black stripe I set my timing about 8 degrees BTC my rig runs good I plug the timing set controlwire back in my rig still runs good it dosen't seem to have an effect on the way it runs, then I shut it off and restart it and it barely runs and when I look at my timing with a timing light it's all over the place retard/advance jumping all around soon as I unplug the timing set control wire it runs good but without the ECM controlling the timing I have no advance. Do I need to have the chip in the ECM reprogramed or is it possible the ECM dosen't like the signal it's getting from my HEI pickup coil. Has anyone ran into this problem I would sure appreciate some advise.