It ran ran Fine Yesterday, well kind of, and now it doesn't start

[ArdWrknTrk]

Try putting your timing light on the coil wire and pointing it at the driver's seat.
Cycle the key on and off.
The coil should discharge no matter what when the power stops flowing.

If you don't get a spark then it is that the coil is not seeing any power, not in the module or distributor.
Just a quick and dirty before you go looking.
Yes, you can always check for power to the horseshoe with the key on.
But if you already have the timing light out you can quickly eliminate the possibility that the ignition is not being charged.

It's always good to check the black wire brass grounding tab inside the distributor.
That is the only ground for the ignition.
You can have plenty of power going to the coil. If it doesn't have anywhere to go (in order to create a magnetic field) nothing is going to happen.

Just a couple of quick thoughts for the fundamentals of a no spark condition.  

[Gary Lewis]

I would check out the wiring to the DS-II module, as shown below from the 1985 EVTM.  Check the voltages at C321 and C323, which will tell you if the wiring is solid.

[Bulletproof250]

These are the results I've gotten I think I may have a bad coil as well from the measurement that i took with the supply wires. And I performed the quick check with the Timing light, no flash from the coil turning the key on and off, tried a few times double checking connections.

 

[ArdWrknTrk]

Your coil voltage readings seem normal to me.
As does the readings at C321.

Does W32 get power while using the starter?
Does the reading on 144 fluctuate when the reluctor wheel in the distributor is turning?

What are the ohm's across the distributor pickup (144 to 147) when unplugged from the module?

[Gary Lewis]

I agree with Jim.  But I'd add that not getting a spark when you turn the key off isn't a conclusive test.  All of the modules I've played with did spark in that condition, but the EVTM doesn't list that as one of the tests so the engineers must not have thought it was a legit one.

[Bulletproof250]

OK this is the few readings that I got before "IT STARTED" after it idled rough and smoothed out it did stall twice one time I could tell there was something not quite right about it. It was idling just fine and then just died (like someone turned of the key)

Wire 144 to Grd- 3.6k at rest
Wire 144 to Grd- 3.6k to 0L while running
Wire 144 to 147 was sitting bout 15.3 to 13.9k while running

But then it died, and I restarted it and I was seeing

Wire 144 to Grd- 0.000Oohms to OL while running.

Do you think I might be on to something here?

Wire 144 to 147 was sitting bout 15.3 to 13.9k while running


Then since Jim mentioned the reluctor I started looking into the distributor a bit and I saw this:

[ArdWrknTrk]

The other tab is screwed down.
There's two tabs on the strain relief but only one gets attached.
Probably some other distributor uses the other side?  

I'm not sure about that gap on the pickup.
I'll have to take a look at mine when I get home.

[grumpin]

On the gap, I recently replaced my pickup, I noticed the old one touched. The new one had a small gap.

I’m assuming once it starts spinning it makes a gap.

Edit: also as Jim said, only one tab is used to hold that part of the pickup in.

[Bulletproof250]

Is the coil supposed to be loose? That is how I discovered the gap. I can move it back to make it have no gap (see the coil position in the picture below). is this possibly my intermittent issue? For clarification the fastening "tab" that I'm trying to describe looks to be a ring tongue terminal-like attachment point, however I'll agree this doesn't look as though it has been attached for some time.



Thanks for taking the time looking at this mundane issue, I'm doing my best to try and troubleshoot, ands understand the problem, before I go my usual route and throw parts/$ at it.

[ArdWrknTrk]

There's no threaded hole under that second grounding tab. It was never attached.
The brass tongue on the other side is enough. (although it is the only ground point for the entire ignition system)

No, the pickup coil should not be free to change the gap between itself and the reluctor wheel.
That dimension is fairly critical.
Maybe it has come free from its mounting plate?

[Bulletproof250]

Thanks Jim,

so what you're saying is that, the sketching looking connection on the other side of the grounding termination is "Suspect" I agree. Although, since we agree that the coil for the pick up should NOT be loose. I'll start with replacing that. During which time I'll put in the little extra work to clean up that area before Install the new one.

Does anyone have a recommended manufacturer or PN to replace this component with? I'm currently looking at a Standard Motor Products LX204:

[ArdWrknTrk]

It certainly couldn't hurt to clean up the housing with scotchbrite and put a tiny amount of silicone grease to stave off oxidation when you install the new pickup.

I'm afraid I don't have any recommended brands any more.    
Back when these trucks were built, Standard (and their Blue Streak line) were top notch ignition components.
I wouldn't hesitate to use the LX204, but I can't vouch for it.

We do our best to get quality components, but times change.

[grumpin]

I had a problem with both Standard pickups from NAPA.

Ended up ordering a Motorcraft.

Search the forum for Non EEC 460 distributor.

Edit: removed link as it’s not working for me. Add text.

[Bulletproof250]

Thank Jim, Thanks Dane.

I'll let you know how it turns out, I imagine much better than it had been before.

Does any one know where I can find the connectors for my ignition harness? I'll have a new Module and new Pickup coil for installation but the poor plugs and the harness are in sad shape....

[ArdWrknTrk]

The module side (4 pin) is available, but the orange/purple/black distributor side is not available to the best of my knowledge.
Except as part of the Painle$$ Wiring DuraSpark harness. (#30812, $86!)
And I can't see paying that much for 4 connectors and a couple feet of wire...
You do get a ballast resistor that you don't need if you wire it in as stock where there was a DuraSpark II already.

[ArdWrknTrk]

That's good to know, Dane!  

Thanks for sharing your experience and setting the record straight.

[Bulletproof250]

Dane,

Am I searching for the entire Distributor? or just the internal components associated with that Distributor?

[grumpin]

I replaced 12A112, the pick up coil, probably not the right terminology, but what I use.

If you get the Standard I’m curious to how it works for you.

[ArdWrknTrk]

AH! So not the Standard Motor Products brand, but NAPA/Echlin parts?

Sorry, I think I got confused.  

[grumpin]

Yes, I’m confident SMP makes the NAPA ignition parts.