[MPKind]

Been getting occasional cut outs at hard acceleration up around 5k in 1st gear. Been going back and forth between fuel pump or ignition.

Thought it was the pump since the tach stayed at the RPM. The coil was still sending a signal to tach.

3 days ago it cut out at cruising speed, but after 2 seconds it fired and I kept going.

Yesterday, I had to have it towed home. AAA to the rescue. I was sure it was the fuel pump. Once home I verified there was no gas squirting, but there was fuel after all. So I pulled a plug, no spark, but there was a signal off the coil primary to the tach and I could get a dwell reading while cranking.

It is a points system. New FAST coil, new Blue Streak ignition parts. No broken wires.

Tests I’ve performed so far are suggesting the solenoid. My thoughts are that would prevent it from starting, but why would it kill it once running when the starter isn’t doing anything anyway.

Other possible items could be the ignition switch or perhaps it’s at the bulkhead connector.

More testing after work today.

[Bill Hanlon]

Tach and dwell signals working while the problem occurs hints that the problem (if electrical) is in the coil, the rotor or the high voltage wire from the coil to the distributor. Does a timing light fire when the problem is occurring?

[steve25]

With the age now of these point distributors many times I have seen the insulation dry rotted off the wire that runs under the plate to the points.

This can make for intermittent shorts and no spark and with enough time and bad luck a 100% short all the time.

I have had two cases of this where the visible part of this wire above the plate still looked good, so don’t be fooled.

Check for a short with a ohm meter, or just be on the safe side and replace that length of wire back to the coil.

[george kujanski]

My experience is that if the ignition cuts out while running under load, you will get a backfire thru the exhaust. When the ignition cuts out, unburned fuel gets into the exhaust, then when the ignition fires up the unburned fuel gets lit.

George

[MPKind]

Originally Posted by Bill Hanlon

Tach and dwell signals working while the problem occurs hints that the problem (if electrical) is in the coil, the rotor or the high voltage wire from the coil to the distributor. Does a timing light fire when the problem is occurring?

I have not checked any induction on the coil wire with the timing light yet. I did pull it off the dist and held it next to a ground strap while cranking. It didn’t arc. Appears to be in the secondary circuit since the coil is getting feedback from the points, it appears the primary circuit is OK.

[Schurkey]

Originally Posted by MPKind

It is a points system. New FAST coil,

WHICH FAST coil?

The PS50 and PS60 would not be compatible with points. PS20 and PS40 should be. Others may/may not be compatible.

[Formulas]

If you have a multimeter check resistance / continuity between carbon button inside and center coil post terminal on outside of cap

[Half-Inch Stud]

Had an internally shorted sparkplug cause a great pause with exhaust report.

[Dragncar]

Change you condenser then you might try a different coil.

[MPKind]

Update. Did a few more simple tests with the Flukemeter and culprit was revealed.

It was THE COIL! What a shock. HA!

Pulled out the old MOTOR manual to see what the ohm range should be. The primary was within spec, the secondary circuit was fried. Over 900 ohms. Should be single digits. 3-4 ohms. Had an old Delco 202 coil in the shed and it popped right off. So much for the F.A.S.T. replacement coil I installed last fall. What a piece of junk.


Sent from my iPhone using Tapatalk

[MPKind]

Originally Posted by Schurkey

WHICH FAST coil?

The PS50 and PS60 would not be compatible with points. PS20 and PS40 should be. Others may/may not be compatible.

It was a PS40 for points. It failed after less than 1000 miles.


Sent from my iPhone using Tapatalk

[VCho455]

What year car was this in?

In early cars without an ACC position on the ignition switch leaving the key in the run position without the engine running can cause coil failures especially the aftermarket high output versions.
The original OE coils were more durable and you were more likely to burn the points up first while listening to the radio at your local make out spot. But with a modern electronic ignition system the coil becomes the weakest link.

[Schurkey]

Originally Posted by MPKind

Pulled out the old MOTOR manual to see what the ohm range should be. The primary was within spec, the secondary circuit was fried. Over 900 ohms. Should be single digits. 3-4 ohms. Had an old Delco 202 coil in the shed and it popped right off. So much for the F.A.S.T. replacement coil I installed last fall. What a piece of junk.

Primary should be single-digits, 1--3 ohms. Few turns of relatively heavy-gauge wire.

Secondary would be hundreds or thousands of ohms. Lots of turns of fine wire.

Originally Posted by MPKind

It was a PS40 for points. It failed after less than 1000 miles.

That's really disheartening. I've got a couple of the similar PS50 (for electronic ignitions) still in the box.

Wondering if they changed the design. Used to be advertised as "oil-filled", now they're jabbering about "epoxy-filled".

[MPKind]

I had it flipped…long day. It was the primary that failed. Secondary resistance was ok.

Correction. It was a PS20 coil.

[steve25]

That coil is designed to be used on 9 volts other then when cranking.
Are you running that off of the ballast resistor it shipped with ?

[steve25]

One thing for all to keep in mind and that few seem to know who do not have a electronics background is that you should never crank over a a motor with a main / central spark coil for more then 5 seconds with no place for the spark to go, as in no plugs hooked up, or the cap off but everything else hooked up.

When the coil is still being triggered the coils secondary side is still producing a spark and with no way to get that high voltage produced to ground the coils secondary winding will arc across itself.

The higher the secondary voltage the coil is designed to produce the more likely it will be for that voltage to arc thru the enamel insulation used on the wire of the secondary.

On a factory 45 year old spark coil the insulation on the coils secondary windings is likely already compromised and ready to fail just due to vibrations and heat cycles, so don’t push it over the edge!

[MPKind]

Originally Posted by steve25

That coil is designed to be used on 9 volts other then when cranking.
Are you running that off of the ballast resistor it shipped with ?

No ballast. It’s a ‘65 Pontiac. It has a resistance wire for running mode. Nothing special about that coil other than it’s advertised to work with a points system. I wouldn’t mount a ballast on the firewall anyway. Never came with one. That’s a Mopar deal.

As for the vintage part. Clearly it’s proved to more durable than the FAST coil. I was using it awhile last fall when I ordered the FAST coil. It’ll do until I find the right replacement. Needs to be the correct diameter to fit the coil bracket. Most after market coils are slightly bigger than the Delcos so they don’t fit. Back to the drawing board.

[MPKind]

I stand corrected. Ballast is required with the PS20/40 coils by FAST. “The large print giveth, and the small print taketh away.” It failed because it burned out from overload. I f’d up and purposely left the ballast off the car.

Can we sell a coil that doesn’t require additional parts to operate properly? Is it too f-ing hard to sell a product that’s similar to the original in setup and appearance? If it’s a Mopar or similar swap the ballast, but on a mid 60s GM Delco system? No.

[Bill Hanlon]

Like this?

https://www.autozone.com/ignition-tu...E&gclsrc=aw.ds

[MPKind]

Originally Posted by Bill Hanlon

Like this?

https://www.autozone.com/ignition-tu...E&gclsrc=aw.ds

Would you believe that newer canister coils have a slightly larger diameter than Delcos? They won’t fit in the bracket. It won’t close the part that bolts to the head. There are a couple that are the correct diameter. FAST and one or two others. Generic ones from the local parts store are likely too big.

I suppose I could find a longer clamping screw and bolt.