Well, Thats the magic statement right there: I got a spark when I turned it off. That means; A) the ECU is alive, and B) the coil is working, and C) all the primary wiring is good. So now, the number one thing is this; is your brand new battery any good. Second is are your connections good; to/from the battery?, to the start relay?, to the starter?, ground returns? Is your starting system still suffering with slow cranking?
- All these questions lead to this; If during cranking, the battery voltage falls too low,below about 9vdc, the ECU may not trigger the coil.
-Say you have a bad starter, which pulls the voltage down to 9volts or less, or a weak battery, or a discharged new battery, or poor connections, etc, or any combo of things which result in the low cranking voltage. That could be your problem.
-Now on the off chance that your cranking voltage is not in the basement, try part 2 of the spark test that you already started.With the coil wire removed from the cap and air-gapped to ground about 1/4 inch or so, again prove the ECU by cycling the key on/off. Each time the key goes to off you should see the one spark.same as before.Are you good? if yes part 2 is crank it for just a couple of seconds. The coil should be shooting a river of sparks.If it is streaming sparks, that proves the distributer shaft is turning, the trigger is working, and if your no start problem is ignition related, then the problem is somewhere in the cap/rotor/wires, or plugs. Now if it isnt streaming sparks, you have to add the trigger and dist shaft to the list.And quite possibly the dual ballast resistor.Although I have never seen an ECU successfully do the key-off,one-spark test with a bad resistor block.
If your system passes all above tests, then your no-start is not an ignition problem.
In my experience the reluctor gap is not critical.If it falls between 0 and .020, it will trigger the ECU. A gap around .011 is pretty good and is set with a non-metalic feeler gauge, usually brass.Otherwise you get the problem you experienced. Im not saying it cant happen, just that I havent seen a sloppy upper end in the electronic dizzy cause a no-start.
-The two small wires on the back of the alternator; blue and green, dont care which F terminal they go on.The blue wire brings battery voltage through the ignition switch. the green returns it to the regulator. The engine will start/run just fine with them disconnected, at least for a while.