No Spark

Caperodder

Caperodder

Member
Hello all,

driving the Scout last night, and it began to run very rough, then died. Towed it home and began checking everything out.

No spark. Checked the points and condenser, and everything checks out. Pulled the coil and have 1.6 ohm primary, 9.2k ohm secondary. Again checks out.

Sometimes I get an extremely weak spark at the points when manually opening and closing with a screwdriver, ignition on.

I'm only getting +4.98v to the plus side of the coil when the ignition is on. Shouldn't it be like 12v or the same voltage as the battery? The coil uses an external resistor. Don't know if this is a valid test, but I hooked up a test lead from the + side of the battery to the + side of the coil. No effect. Battery is at 12.98v.

Scout is a 1972, 304 w/Holley points disty.

Looking for clues.

Thanks,

-brett
 
Salt air?? Blue fish oilstink? Livin' large???? Beach sand in the distributor? Parked too close to that chev motor in the garage?

Your description indicates that you "hot wired" the coil from the battery and still no fire in the hole??? That is very strange! Doing so eliminates both the bypass wire run and the resistor wire run to the coil positive terminal, along with the bulkhead connector issue. A hot wire from battery positive to the coil positive will create a start/run condition if the coil is ok along with proper point gap and a condenser that is electrically ok.

Look very closely at the breaker points with a strong light...do you see any evidence of heavy arcing at the contacts, does the insulated (moving) contact arm show discoloration from heat (as in turned blue) and the resulting distortion? Did ya re-set the breaker point gap to a nominal 0.017" with a feeler gauge (28>32* dwell)?

It would be a freak occurrence, but a condenser can develop a short-to-ground internally, replace it and see what happens, any condenser that will mount in the hole will work just fine for testing.

The biggest maintenance issue with breaker points is the fact that even when properly installed with "cam lube", the rubbing block wears down over time allowing the gap to close up, resulting in a huge change in dwell. That is why back in the day, the typical tune-up interval was a nominal 15,000 miles. New points should always be cleaned with contact cleaner before installing to get the resistance of the point set as low as possible (0.2 ohms or less) when actually installed.
 
Hello michael.

I knew, without a doubt, that you would respond first. We now have fire in the hole!

I took an old beatup set of points and stuck em in. ( I usually keep these in the glove box for roadside service). Yes they work. Moral of the story? Just because a set of points look good, and bench test ok with an ohm meter, don't mean they-re good! Live and learn. Should have known, that with all other conditions good, it was in the "switch". Been thinking of converting over to pertronix....now the decision is made.

Hope all is well with you. Striper fishin this year was exceptional. Even got some false abacore on a fly rod. Like catchin a huge vibrator!

Thanks for the comeback. We're on the road again!

Best regards,

-brett
 
caperodder said:
hello michael.

I knew, without a doubt, that you would respond first. We now have fire in the hole!

I took an old beatup set of points and stuck em in. ( I usually keep these in the glove box for roadside service). Yes they work. Moral of the story? Just because a set of points look good, and bench test ok with an ohm meter, don't mean they-re good! Live and learn. Should have known, that with all other conditions good, it was in the "switch". Been thinking of converting over to pertronix....now the decision is made.

Hope all is well with you. Striper fishin this year was exceptional. Even got some false abacore on a fly rod. Like catchin a huge vibrator!

Thanks for the comeback. We're on the road again!

Best regards,

-brett
Click to expand...

yeehaw!!!!

I still have points in the Holley-fired/t'all were in currently takin' a vakashun. Even though it's firin' a tricked out msd sparker system. No doubt, today some time, we'll loose the breaker points while on some backuntree road draggin' the trailer and I'll have to do the same!

I haven't had time to swap the distributor out for one of our experimental Holley mag trigger versions yet, that will be done as soon as we get home.

If the planets align just right, we're gonna try and get up yore way late next spring to visit the relatives and fish with ya!!
 
Make sure ya let me know when yer in my neighborhood!

Regarding the pertronix, per your excellent stickey, looks like I have an aluminum Holley with a curved point set. 2-3/4" condenser wire. That would convert to a ho-141 pertronix? Just checkin before I plunk down the money.

Thanks,

-brett
 
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