Other than setting the initial timing, I don't think you can do anything else, as the EEC-III computer controls it all from there on. But maybe thats your question, the initial timing. The tooth on the pulse ring behind the damper should be solidly on the CP sensor, when the crank is at 10 BTDC as read by the bracket. But thats mechanical, and shouldn't change unless something broke. I vaguely remember something about the rotor in those Duraspark III's... is the ROTOR ITSELF adjustable or something, rather than trying to turn distrib? I think the distrib body keys in, and can't be turned, but I may be wrong about that.
Maybe one of the guys that have EEC-III and Duraspark-III can help out with the adjustment?
The EEC-III system is somewhat of a mystery to us (me). I have this system and have studied it for some time now. I understand the logic that the module works with, but can't see how the system physically works. One would think that a computer under the dash controls it, but none do. I tested this. The module needs only three wires on the harness to work. I actually disconnected the wire harness to the computer and the truck fired up and ran. I then unhooked the MAP sensor thinking this controls advance, but it doesn't. In the EEC-IV system, there is plug that you pull and this counteracts all electronic control of the advance and you set the timing by turning the distributor and plugging the connector back in. The EEC-III does not have this plug. I just set my timing by turning the distributor until I hit my desired time, 16 BTDC. Whats funny is you can run the engine clear up to red line with a timing light looking at the marks and they will not move from where you set them. This astounds me, but the engine runs fine. I have since rebuilt my engine, removed all emissions, installed a Holley 600cfm 4bbl carb, completely removed the computer, wire harness to the engine compartment, all sensors and all but three wires on the stock ignition system and the thing runs like a champ. I have pictures to prove it if you want to see. Therefore, this ignition system baffles me. I have had no problems with my factory ignition on my modified engine, but I did add the Holley Strip Ignition box and performance Ignition module to get rid of the internal rev limiter. It cut out before the engine was done. Its been over a year since I've done this and haven't had problem one with reliability.
OK, Found it!
This is for an EEC III with Duraspark III. The distributor has no wires on it, other than the plugs and coil wire. No vac advance unit on it. Has a Bi-Level cap and rotor. This means rotor has two spark paths - one high to 4 plugs, one low to 4 plugs, with underside of cap having two alternating matching levels. The coil is the familiar round cylindrical oil-filled style, not the E-frame type of later years.
To install distrib, match notch on holddown flange with clamp bolt hole in block. Do this while near TDC on comp. stroke of cyl. #1. The large slot on the top of the distrib. sleeve assembly (on top of shaft) should roughly line up with the notch in the Adapter. The Adapter is the middle section of the Distrib, that the cap fits onto. If the slot isn't close, pull out the Distrib and turn shaft slightly, and try again (meshing the next set of teeth).
Now here's the Check Procedure:
With cylinder #1 on Comp. stroke, rotate crank by hand until the rotor alignment tool can be inserted into the slot on the sleeve, and into the notch on the Adapter. The tool is a small rectangle of metal, that fills the width of the sleeve slot, and can fit into the notch on the Adapter. I'm sure you can fab something there.
Now read the timing mark down on the damper. If it reads within 4 degrees, plus or minus, of 0 TDC, thats it, your done. If not, read on...
Rotor Alignment Procedure:
Rotate crank to put cylinder #1 on 0 degree TDC on damper, being sure its in Comp. stroke.
Loosen the two screws on the sleeve assembly, and rotate the sleeve so tool can fit in slot on sleeve and notch on Adapter. Tighten screws to 25 - 35 lb.in. and remove tool.
The procedure is from a Ford manual. Since there is no pickup of any sort from this distributor, the EEC-III is using the blip from the Crankshaft Position Sensor (CPS), and the engine RPM, also from the CPS, along with temp, load, etc. etc. to predict when to fire plugs. So the Distrib in this setup is just a rotating switch to reach each plug. The EEC controls all advance/retard. And the rotor alignment keeps it in phase with what the EEC wants to do.
I wish you luck dealing with the EEC III system.I had that system on my 82 Bronco and after 2 months of trying to fix it I finally ripped it out. The computer doesn't seem to really control the timing but I know the Ford book says it does. According to the manual you can't time the motor except to set the primary timing.
Good luck with it.
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