not firing

climb2safety

climb2safety

Member
I have read this thread and think I have found my issue with no spark.

Let me provide the back ground then I will tell you what my issues are...

During a trail ride, my Scout (1980 sii, 304) started having a power failure. We got it back to camp and the master mechanic on hand pointed out the coil was blazing hot, was fried and sent me to the auto parts store for a master blaster II. Got back to camp, installed, fired up and ran well for the past 4 months until now - no spark.

This is where the thread I was reading comes in handy, but still a little over my head. I am running a master blaster II into the prestolite distributor and have a pertronix 1481 installed. From reading that thread, it sounds like the master blaster is not compatible with the pertronix and will cause it to fail. Is that correct?

If that is true, what are my options for correction? My Scout is 80% Sunday joy riding and 20% trail riding?

Am I missing anything else?
 
The correct p-tron module for a prestolite points distributor is p/n 1483 and for the solid state (breakerless) version is 1483a. Are you certain of your distributor model? The p-tron in a v8 engine requires a coil with a primary resistance of 1.5 ohms. The definitive answer regarding whether or not your current coil is appropriate can be determined by probing the coil +/- terminals with a digital multimeter set to measure resistance in ohms on the lowest setting. All wires should be removed from the coil +/- terminals prior to this test.
 
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You could measure the primary resistance of your current coil. It might be fine. If it must be replaced, there is certainly no need to go hog wild on a high dollar piece. An oem replacement will suffice. I'm not up on how the msd would jive or not jive with the p-tron, but they are nice units with the right ignition configuration. It is important to have the right p-tron module for the distributor model.
 
I am not sure what unit is currently in the dizzy but there is a p-tron 1481 (Holley) in the glove box.:yikes:

I guess now the question begs p-tron or p-tron II...

Where can I find the exact model of the dizzy?
 
If you happened to have a Holley curved points distributor on hand, you could stab that in and toss the 1481 in it. I've edited a prior post in this thread for clarification purposes. You May want to review before making any purchase. There were two versions of the presto used in IH vehicles. One with points and one without. The electronic version was by far the more commonly installed item and considering the model year of your Scout it would be the likeliest choice, but we know how shit gets swapped around on these rigs over the years, so anything is possible. That's why it pays to do your homework before popping for parts. Any time one has the option of going with a p-tron II instead of the first gen, it is a worthy upgrade. The first gen offers no component protection in the event of an inadvertent leaving of the ignition switch in the on position with the engine stopped. This will often fry a p-tron first gen in short order. The p/n for a presto p-tron II is 91483a. Again, the 'a' suffix means it is meant for the non-points (electronic) version of the presto dizz.

And this just in...there is a p-tron 1485a and 91485a also meant for the ihc presto dizz. Bottom line...you better look for the p/n on your dizz and post it here. It should be something like...idn-400x.
 
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I don't have an extra dizzy so I cant test the 1481, maybe I can swap with someone in our club...

I am contemplating getting the pton vs ptronii. My thoughts reason with the ptron b/c I am the only driver. I am aware of the "on" position issue and am certain I wont do this... As a result, I can almost purchase 2 for the price of 1... Unless there is any other downside, I am going this way.

Once I purchase, install, I will report back...hopefully with a running Scout!!!
 
One thing we haven't delved into much is how extensive your spark checking was. Can you please go into some detail as to what and how you checked for spark? I just want to make sure we aren't putting the cart ahead of the horse from a diagnostic standpoint.
 
There was no spark to the coil, checked visually at night and after the proper coil was installed - went with a screwdriver and a puckered you know what...still nothing.
 
Try running a temporary jumper from the battery + to the coil + and crank it. This would bypass any potential issue with the ignition switch and/or circuitry between the switch and the coil. Remember to remove the jumper wire after performing the test.
 
I didn't test the jumper as you suggested because the p-tron came in the mail today. I am kinda an insta grato fella. Installed and it cranked on the first try - that hasn't happened in 4 years. She always been hard to wake up.:dita:

now I am wondrin' if the p-tron goes out over time (because it has been a little sluggish starting), if it just gives up/craps out, if I accidentally left in the on position, or if the mds burnt it up???


Anyhow - I am off for a drive - its been a month!!!
 
Outstanding! One could probably speculate all day long as to the precise failure mode of your prior module and what caused it. The most common cause of failure with the first gen units comes from leaving the key on with the engine stopped. That situation is commonplace and well documented across the owl gorzz interwebz. Glad she's back rumblin' for ya again.
 
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