Well, the inputs/outputs to the ECU are:
On the 8-pin connector:
Servo Position Sensor GND (-) - Blue/Grn wire
Servo Position Sensor Signal (RC/V) - Lt Grn wire
Servo Position Sensor PWR (+) - Yel/Red wire
Battery + is the Red wire, goes to the regulator (no battery!)
Ign GND, which goes to the coil and voltage reg, as well a frame gnd, is the Grn wire
Note: the engine stop switch is spliced into the Grn wire also (Blk wire)
Servo Motor PWR (+) - Wht/Blk wire
Servo Motor GND (-) - Wht/Grn wire
On the 4-pin connector:
Eng stop switch - Blk/Wht wire
AC - Wht wire, goes to alternator (stator) as well as regulator
Ign pulse generator GND - Grn/Wht wire
Ign pulse generator POS - Blu/Yel wire
If you check the Servo sensor resistance @ approx. 70 degrees F (Yel/Red & Blu/Grn wires @ 8-pin connector) it should be 3.5 - 6.5kohm. That's really the extent of the testing in the book. There's no info regarding the ECU operation or control of the RC valve, other than the initial operation ("The RC valve operates from fully closed to fully opened and returns to fully closed position in the initial stage after engine starts"). That's it.
Are you sure it's an RC valve issue? What exactly is the "driveability complaint"?
Oh, and keep in mind that even with your meter set to ohms, you can still have continuity on a bad wire so long as there's still at least 1 strand in the wire that's not broken - even if the rest are - but when current is applied, the resistance will go up and a voltage drop will occur, which can create problems. You can load each wire with a battery and your test light, then wiggle test the harness - if the test light flickers or gets dim, you've got a problem. You can also have your meter connected at both ends and set on the volts scale while doing this - you are now testing voltage drop on the circuit - and it should be very close to zero, any more than about .2v is a problem. If you want me to scan the pages in the manual & email them, I can. HTH