My 40 shut off on the fwy, any thoughts? (1 Viewer)

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So I’m driving my recent purchase down the FWY when suddenly my engine cut off, I was able to roll off to the right away from harms way. First thought was my 2f just had the widow maker. Anyways had it towed back home..... so far this is my diagnosis

Its not the engine, turns over just fine.
I pulled one of the spark plugs, and I’m not getting any spark. I’m running a DUI distributor with an internal coil. Went on ther website and followed troubleshooting tips, distributor appears to be just fine. Any thoughts?
 

POTATO LAUNCHER

TLCA #6928
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Can you verify that the distributor has 12v when the key is in the run position. If it does your loss of spark is very likely the ignition module under the cap near the base inside the body. They are cheap and available at any VatoZone or Odaley's. Make sure you use dielectric grease when you replace it.

20180826_123900.jpg
 
Joined
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Can you verify that the distributor has 12v when the key is in the run position. If it does your loss of spark is very likely the ignition module under the cap near the base inside the body. They are cheap and available at any VatoZone or Odaley's. Make sure you use dielectric grease when you replace it.

View attachment 1775370
Yes is have 12v power at the distributor. I’ll replace the module. Fingers crossed
 

POTATO LAUNCHER

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Might verify the correct module. There is the one pictured and another with two spade plugs on one end and 4 smaller pins on the other. Not sure which one DUI uses.
 
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Did everything go off or just the engine? Did you still have lights horn etc.?
If so...Make sure the wires to the distributor pick up are not broken. Check dist cap and rotor. Make sure that there is 12 volts or better to coil. Check all grounds.
Is the brain in a dry spot and is it bolted to good ground?
bolt.jpg

You need a good ground though the holes in the brain.
Low voltage will cause them to go out.
Stopping all at once is a sign that could be the problem.
 
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Can you verify that the distributor has 12v when the key is in the run position. If it does your loss of spark is very likely the ignition module under the cap near the base inside the body. They are cheap and available at any VatoZone or Odaley's. Make sure you use dielectric grease when you replace it.

View attachment 1775370
Is this ignition module specific to a DUI dizzy? I have a similar engine shut off problem from time to time where after the engine gets up to temp (30 mins) it will shut off. I have to pull over and open the hood to let the heat dissipate and then it starts back up. I'm running this dizzy: Complete Mel's Electronic Non-USA Distributor - JTOutfitters
 
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Is this ignition module specific to a DUI dizzy? I have a similar engine shut off problem from time to time where after the engine gets up to temp (30 mins) it will shut off. I have to pull over and open the hood to let the heat dissipate and then it starts back up. I'm running this dizzy: Complete Mel's Electronic Non-USA Distributor - JTOutfitters
I’m not sure but it’s worth the try, you can pick up a module up for around $20. For the DUI, HEI , They are a universal GM product. But I’m a firm believer of you get what you pay for so we will see, I just wanted to make sure that was my problem. Per all the research, its a common problem, and recommend to have a spare. Good luck.
 

POTATO LAUNCHER

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All the HEI type distributors use one of two modules. There are many variants of the same one. MSD, Accel, Petronix, Summit, Jegs to name a few. Bottom line is that this module is key to producing a spark for ignition. No way to bypass it so it's definitely required no matter the make or cost. I have tried all of the above and the cheap ones do the same job on a regular HEI setup.
 
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All the HEI type distributors use one of two modules. There are many variants of the same one. MSD, Accel, Petronix, Summit, Jegs to name a few. Bottom line is that this module is key to producing a spark for ignition. No way to bypass it so it's definitely required no matter the make or cost. I have tried all of the above and the cheap ones do the same job on a regular HEI setup.
Where would that piece be located on mine because I do not recall ever having seen that part before. Still, I have the engine shut off issue and if this is the cause I would like to replace this part to see if I can resolve the engine shutting down. Someone mentioned this part fails due to heat and that's precisely when my engine is shutting off, although I do not have an overheating problem with the engine.
 

POTATO LAUNCHER

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It looks like the electronic ignition that JT sells is not an actual HEI type distributor. Seems similar to what Petronix uses as an upgrade. The system functions similarly but is engineered differently. I have no personal experience with this type, maybe someone who knows them can chime in. Are you still using the ignitor/ coil system for this?

I would suggest maybe calling Petronix directly as the Mel's set up is that type of system. I converted an old Mallory duel point to Petronix years ago and their customer service was very good. At least it was about 12 years ago.
 
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I am using the same distributor , but, a pertonix module. It looks exactly like the Mels one. Mine has been 8 years, never an issue, and I live in heat. I do not know if JT is using pertronix modules or not. ?
 

65swb45

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Where would that piece be located on mine because I do not recall ever having seen that part before. Still, I have the engine shut off issue and if this is the cause I would like to replace this part to see if I can resolve the engine shutting down. Someone mentioned this part fails due to heat and that's precisely when my engine is shutting off, although I do not have an overheating problem with the engine.
Those units typically work until they don’t work any more, not on again, off again. However, it is very common for 40 year old primary ignition wiring to break down internally, and with only a few strands of wire still working, for heat saturation to cause ignition problems.

The easy test for that is to run a piece of fresh wire as a jumper from the ignition switch to the coil to see if the problem goes away.

I had a customers truck with a heat saturation ignition issue that stumped me 25!years ago, until I replaced the factory wire that went from the points to the coil negative. That’s how I learned how to never rule out the factory wiring.
 
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Those units typically work until they don’t work any more, not on again, off again. However, it is very common for 40 year old primary ignition wiring to break down internally, and with only a few strands of wire still working, for heat saturation to cause ignition problems.

The easy test for that is to run a piece of fresh wire as a jumper from the ignition switch to the coil to see if the problem goes away.

I had a customers truck with a heat saturation ignition issue that stumped me 25!years ago, until I replaced the factory wire that went from the points to the coil negative. That’s how I learned how to never rule out the factory wiring.
Thanks. I haven't heard this recommendation yet. Just to recap my issue so you have the full picture here it is. After a period of time from driving around and idling in traffic my engine gets up to normal running temperature. While driving the engine will start to sputter like it's not getting gas and then will completely die. I pull over and pop the hood to let heat dissipate and after anywhere from 10-15 minutes the engine turns over and starts just fine. I drive off and head home because if I continue to drive the problem comes back within 10 minutes. So something is happening where the engine heat is shutting something down. I've chased this problem for a year now. Replaced the old dizzy with the JT non-US dizzy with the electronic ignition upgrade (which is Pertronix), replaced the coil with a JT coil at the correct ohms, I've wrapped my fuel line with heat reflective tape just above the header to rule out vapor lock, I've run two fuel filters to ensure the fuel is clean, and I've upgraded my fuel pump to a higher powered one to ensure it can push the fuel all the way to the Weber 38 carb.

I do not know what else I can do as that is where my basic knowledge ends. So if this still sounds like an issue of what you are suggesting could you help me out with a play by play on what I need to do with running a new wire as a jumper from the ignition switch to the coil? Where on the ignition switch would I connect it and where on the coil would I connect it? I have attached a pic of my engine below so you can see the setup. Thanks in advance as this has become a very frustrating gremlin to track down.


 

Herb

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Just a wild guess...but, take off your gas cap and drive around and see if the problem goes away. Perhaps it is not venting properly and when the vacuum builds up, the fuel supply gets choked off?
 

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