S.E.V.E.N.

I have a 1987 TII with 102k miles on it completely stock that I acquired a couple months ago. It was running pretty well for a while until recently when I cranked it up and it ran very badly. Symptoms were: no power, almost no acceleration, very poor idle. I began with checking the basics even though I suspected a sensor of some sort had gone out. I checked air flow, checked for spark, checked for compression, checked for leaking vacuum lines, and also built a LED code reader. Everything came back fine and it gave no flash codes. The car has the low impedance injectors with a resistor block. I hooked up an LED test light from the injector negatives on the ECU to the main positive wire for the injectors about a foot away and tested the front injectors first. The lights flashed with each pulse as would be expected, when I checked the rear injectors I got nothing at all. at that point I checked for voltage on the two rear injectors and again got nothing.

So very long story short, my ECU is cutting off fuel to the rear rotor BUT isn't giving an error code. My question is can anyone tell me why the ECU would do that? How can I troubleshoot this and fix it?