Michael
Try looking in a service manual. I think they have instructions for testing primary and secondary coil windings. If you change the condenser again, make sure you use the correct type.
We, along with so many other people on this forum, have been running 6V points and condensers forever, with no problems at all. It is so much easier to get a set of points and/or condenser out of the trunk, or local auto supply ,install them and be back on the road, VS the Petronix. YES, the Petronix is a very good upgrade, works well, BUT if it goes bad, you are stuck where your at until you get a new one. You have to start with known good parts. If you use a NOS condenser, there is no guarantee that it is good. Sitting in a box for 50+ years,and most have a cotton lacquered lead??. ALWAYS inspect the lead from the outside post of the distributor to the inside very closely. These fray,wear-out or have been abused over- again 50+ years, and can be a problem.
You can always have a spare, points and condenser distributor in the trunk, if you go to the petronix, safe than sorry type of issue. Just my 2 cents
Eddie has also made a good point "make sure you use the correct type"
[quote="Eddie Adler" post=13401]Michael
Try looking in a service manual. I think they have instructions for testing primary and secondary coil windings. If you change the condenser again, make sure you use the correct type.
Hi Kerry - great video, although not really necessary since i'm quite familiar with a VOM and how to use it. Missing two critical pieces of information - 1) what's the spec for the resistance across the primary winding...and 2) sure, the coil checks out at room temp on the work bench, but what about when it gets hot? I need to know how to heat it up safely and to what temp.
One other thing. The shop manual gives a spec for the secondary of 2000 to 10,000 ohms, but for the primary, they rely on a reading of "Good" using a Sun Tester, a piece of equipment I just don't have.
Thanks again.
My Pacemaker, about thirty-five years ago, had a problem of suddenly stopping and not starting again. A mechanic friend found that the condenser wire that runs through the distributor had a worn spot in the insulation and when the distributor moved just right the wire would short out on the housing and the car would stop. I recall the wire was fine and very flexible so I went to Radio Shack and bought 50 feet of speaker wire, and used three inches of it to solve the problem. If I ever have that happen again I have plenty of wire to fix it.
Geoff Blake
[quote="Doug Wildrick" post=13403]We, along with so many other people on this forum, have been running 6V points and condensers forever, with no problems at all. It is so much easier to get a set of points and/or condenser out of the trunk, or local auto supply ,install them and be back on the road, VS the Petronix. YES, the Petronix is a very good upgrade, works well, BUT if it goes bad, you are stuck where your at until you get a new one. You have to start with known good parts. If you use a NOS condenser, there is no guarantee that it is good. Sitting in a box for 50+ years,and most have a cotton lacquered lead??. ALWAYS inspect the lead from the outside post of the distributor to the inside very closely. These fray,wear-out or have been abused over- again 50+ years, and can be a problem.
You can always have a spare, points and condenser distributor in the trunk, if you go to the petronix, safe than sorry type of issue. Just my 2 cents
Amen.
Michael,
If you have an ammeter, you could see if the coils you have draw about the same amount of current. If they are the same, it is reasonable to assume that both primaries are good.
I'm used to seeing my ammeter showing about 4 amperes when the ignition switch is on but the car not running, and about 2 amperes when it is running slowly enough that the charge light is off. Since this dashboard ammeter has a range of plus or minus 30, my readings are just an approximation.
Per
OK - so here are the results of my heating test on the two coils I have; bottom line - nothing obviously wrong with the coil that was in my car.
[u] Primary[/u] [u] Secondary[/u]
Coil from car - room temp 1.2 ohms 8000 ohms
175 deg F 0.9 ohms 8000 ohms
225 deg F 1.2 - 1.4 ohms 8000 ohms
NOS coil - room temp 0.8 ohms 7000 ohms
175 deg F 0.9 ohms 8000 ohms
225 deg F 1.2 ohms 12,000 ohms (out of spec)
I'm going to try the NOS coil to see how the car runs. More on that later on. I'll also check the current draw, as suggested by Per.
Mike
Mike
Have you checked the primary wire for bare copper as Geoff suggested? If the wire is worn you can get a miss when running or a no start condition. If you do find a bare spot you can use a piece of vinyl tape to fix it.
Michael, this is great info. I think it is so cool that you followed thru and diagnosed what your coils actually read under heat ! I think the heat ranges are on the top side, but great to compare this info with cold components! Good luck, I have total confidence you will be able to find/correct any concerns1
[quote="Michael Cohen" post=13422]OK - so here are the results of my heating test on the two coils I have; bottom line - nothing obviously wrong with the coil that was in my car.
[u] Primary[/u] [u] Secondary[/u]
Coil from car - room temp 1.2 ohms 8000 ohms
175 deg F 0.9 ohms 8000 ohms
225 deg F 1.2 - 1.4 ohms 8000 ohms
NOS coil - room temp 0.8 ohms 7000 ohms
175 deg F 0.9 ohms 8000 ohms
225 deg F 1.2 ohms 12,000 ohms (out of spec)
I'm going to try the NOS coil to see how the car runs. More on that later on. I'll also check the current draw, as suggested by Per.
Mike
Hi folks - so here's the outcome of my test drive with the NOS coil (remember, this is the one that showed the secondary resistance going out of spec at 225 deg F).
I went to the bank, then the pharmacy and then home via a scenic route. Total mileage about 8 miles. When I got home i put the car in the garage, turned it off and then almost immediately tried to restart it: NG!! Which, actually, is good because that gave me a chance to try a few things in my garage.
First, checked the fuel by working the throttle. Could clearly see the two squirts from the accelerator pump jet. Tried to start the car - NG.
Then i poured about 1 Tbsp gasoline straight down the throat of the carb; tried to start it: NG. Conclusion - not a fuel problem.
Tried cooling off the coil with a damp rag - NG
Took plug #1 wire off the plug, placed it near the head and cranked the engine. Looked like a nice spark to me. But still NG.
Then swapped out the (hot) NOS coil for the room temp one that had previously been on the car - car started up instantly.
I'm thinking I have two bad coils, one that has been in the car since I've owned it which fails every once in a while (when hot). The other, a NOS coil, seems to fail easier.
I'm going to buy a new coil and bracket from NAPA to see if that solves the problem. However, since it's an intermittent problem, I won't know for a long while.
Michael
One question. When your car fails to start do you put the pedal to the floor and hold it when you crank?
Yes, that's one of my tests, to eliminate flooding as a potential cause. I should also add, that whenever I start the car when the engine is warmed up I never use the gas until it starts first.
One last thing, I did the current draw test suggested by Per. When the engine is stopped and the key is on, the current draw was 4.0 A (spec is 4.5). With the engine running at fast idle (cold engine), the current draw dropped to 2.2 A (spec is 2.5). Not sure what all this means. BTW - this is with my old coil. I didn't try it (yet) with the NOS one I recently purchased. Another test I need to run is the primary/point resistance as suggested by the owners manual that came with my Sun engine tester. More on that later.
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