watch this video, about half way through it covers what I said specifically about voltage drop test

 

Edited post #89

 

Nice weather and still waiting on parts. I decided to redo the tests that gave inconsistent results. I figured out the reason I got inconsistent readings at the ICM's PIP pin. Measuring voltage while cranking gave the 5v average one would expect. However, bumping the distributor with the remote, I got voltage the whole time. Never below 1v and as high as 11.5v. The tone of the current flow changed depending on the voltage. The voltage would read different depending on where the distributor vane was. And the voltage could be anywhere throughout the 1v-11.5v range.

I thought it was supposed to be on or off. 0v or 11.5v.

@torq'ta 5 8 , you linked the LED PIP test so I wanted to make sure you saw this. The linked test says the flash should be on/off. During my test with the LED the light never goes out, just grows dim between flashes.

@Prototypemech With the meter set to Hz, it read about 4000Hz at 1v up to 65k Hz at 11.5v.

I checked at AutoZone today. The previous owner purchased a new Duralast Gold distributor, rotor and cap. All are lifetime warranty. He can (will) exchange the unit for a new one.

I hadn't mentioned yet that the new cap and rotor are trashed. Cap with brass pins looks new except for the carbon button which is eroded away. The rotor burnt black

 

Autozone Duralast strikes again!

 

Guess I'll have to void the warranty so I can see which way the rotor is pointing when I stab it.

 

Any update?

 

I swapped out the distributor. Not the cause of the current flow. Swapped out the ICM and the system works as expected.

However, the distributor is crap. The drive gear is 180° out. There is no downward end play. I have run the engine for extended periods in the driveway. I'm going to pull the distributor back out to see if the gear is possibly riding on the boss as it should be.. Not optimistic. Nothing that can't be fixed with my neighbor's lathe.

The new ICM came from a Texas Ford dealership. I called their parts department and confirmed the part number embossed on the unit. Parts counterman was helpful. He states that these Motorcraft parts are supplied to them by outside vendors and not by Ford.





I'm ready to move on to the drivability issues.

 

So you saying youre ready, do you mean that you no longer have a spark that constantly grounding out ?

 

so was your issue a roll pin on the distributor then (reading your reply on another thread, i decided to check in)

 

The new ICM is what fixed the subject spark issue. I have no explanation why. The faulty ICM was the push start type but that is not what caused the problem. Many others have installed the incorrect module and apparently none have experienced the issue my truck had. It will remain a mystery to me.

Regarding the junk distributor I just installed, I tried to trade it back to AutoZone for the one I warrantied. I was too late. The distributor I swapped out had at least some end play both up and down. Only 0.002" or 0.003" shaft up play but some is better than none like the one I just got.

Since the distributor is aftermarket junk I can aver with confidence that its roll pin is all that is keeping the gear from rotating on the shaft. As discussed in the other thread, the friction of a press fit stock gear helps prevent gear rotation and takes much of the stress off the roll pin.

I don't like the gear being 180° out but that is very easily corrected considering a loose fit gear. Also, the housing can be rotated enough to compensate for the 11° difference if I don't re-orient.the gear.

I am not at all happy with the lack of upward housing end play. The drive gear is supposed to ride on the engine block boss. Fixing that would require removing the roll pin, dropping the gear an appropriate amount and redrilling.

FWIW: Ford specifies .035" end play. Ideally .017" and .017 down.

 

cant be shimmed? I know that SBC can

 

I was never aware of these.

An Internet search turns up a hundred offerings for 0.5" ID shims for a SBC. My non- exhaustive search turned up none for a stock Ford 0.452" shim set. I don't know the actual diameter of of the aftermarket unit currently installed in my truck but would guess it's sized closer to stock than a GM 0.5". The GM style shims are a much larger OD than I would want in the Ford small block.

Pulling the offending distributor and disassembling I may find the builder simply failed to drive the bushing all the way in. Alternatively, the bushing could be turned down the appropriate amount, not likely to interfere with the pickup/ rotor interface.

I'd probably just move the gear.

 

What do you do with a junk ICM? My 1986 truck with a distributor mounted ICM is a pain to back probe. It lives in a deep hole.

I cut up the junk ICM and used the connector for a ICM breakout box.

Work in progress.

 

you should mount it on the fender with a heat sink

 

If I part out the '95, I will.