My 86 5ks stalled the other day and now will not start. I had stored it for a few months and have had nothing but trouble ever since I stopped driving it daily. I have fuel, but no (or very little) spark. I've done the Bentley checks, and looks like the ECU isn't grounded properly. There is no continuity between the ECU ground pin (#1) and the fuel pump relay pin #47, nor is there continuity between the ecu pin #1 and the ground wire that connects near the back of the intake manifold - this is my problem I think, but if that connection is clean and ok, how will I find the break? Is there a way to fudge an extra ground wire somewhere somehow? Any other grounds to check?

Why did you start doing tests on the ECU. When you tested for spark, was there a weak spark, or no spark?