Help with 7730 on 305 SBC TPI (Speed Density)

[RobertISaar]

I have been trying $8D, but all I'm getting is as described above i.e. 1. SES light On 2. Thermo Fans running full ball even on a Cold engine 3. Cranks but no ignition. Replace with Factory\Modified Prom - Starts straight away.

sounds like you're running into limp-home mode.