Stumped on a spark issue (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

So I’ve got a stronger spark from the coil wire to the dizzy, but is it normal to spark AFTER the key is shut off? I know this probably wasn’t the best place to ground it, but anyway...

 
Weird. It's like it's cutting power to the coil only when cranking. Wiring?
It was almost certainly the non points gap that was the problem, so if everything is back exactly the same it should be fine. No popped fuses?
 
Last edited:
Oh hang on, don't use the HT coil wire to spark test. Use a plug lead, It has to have the dizzy to coil wire connected.to enable distribution of spark
I just realized what you did in the vid. That spark is just the coil discharging after the power is cut. I think

I hope the non gap in the points hasn't fried the igniter. Non gap=non trigger. Where are all the 76-77 hybrid igniter experts?

If worst comes, and igniter is toast, you can bypass the igniter and add a proper condenser and run it as a normal points system.
 
Last edited:
You aren't getting spark based on the video you took... so I'd grab the ignition wiring diagram for your truck and then get your multimeter out and start from the battery and work your way through the coil, igniter until you find where you aren't getting power.

It really sounded like a points issue... but with new points it should have resolved itself.

I'm really surprised this thread hasn't attracted an @wngrog quip about an HEI and Sniper...
 
Last edited:
Yeah you know what I would do.

Have you put a test on the battery? I’ve had Optimas die before. 4 years is about right for a bad yellow top to happen.

As for the spark after. There is a wire in your steering column that will go bad. It’s from
The key cylinder down. Toyota still sells them

This one went out this way but I’ve had them go out where it still went power a few after key was off.

 
While I've had sudden deaths of Optimas as well (converted to Odyssey now) his cranking videos don't sound like a battery that's dying...

Good call on the steering column wire. Could be related to something in that neck of the woods.

The explanation of it running rougher and rougher and only running well at high RPM could be an electrical connection that was going south... and higher RPM's were pushing enough current to arc or push through the resistance of a bad connection. Just guessing at things now.

Multimeter and step-by-step through the diagram. Electrical gremlin seems the only explanation at this point.
 
I woke up at 3AM this morning with an epiphany. The points have a plastic “cover” over where the contactor is and I am embarrassed to admit that I was setting gap on the wrong end! I gapped them at .018 and she fired right up.

The old contactor was worn down badly. I can’t believe I had this new old stock set on the shelf.

Thanks again for everyone’s help. I learned something totally new with this. Now back to driving my favorite 40.
35A936E8-4197-4636-822C-D958A725425D.jpeg
 
Carson you think the old points just burned up and you misdiagnosed that at first?

Only thing I know about points is how to take them off and toss them.

Points don't 'burn up'. It's just metal/metal contact. Emory pad to flatten/clean the faces and regap. The condensor can fail, but a simple multimeter check will tell you if your points are working or not...thats why I and many others run points on old harleys also, they work great when setup correctly.
 
Carson you think the old points just burned up and you misdiagnosed that at first?

Only thing I know about points is how to take them off and toss them.
Although the contactor looked old and cooked, I think the gap must have gradually changed until it finally closed and couldn’t deliver consistent spark. I’ve read that they need to be regapped periodically, which is why most people replace them to avoid another PITA mechanical part to maintain. I knew nothing about points two days ago. Now I’m kind of a fan of the simplicity.

The engine also seems to have way more power than before. Pretty pumped.
 

Users who are viewing this thread

Back
Top Bottom