This is continuing from my first post. I thought I was loosing power to the coil, but I did not have my meter at home to use. After bringing it home from work I tested for power to the coil after the the engine quits running, it has power. Turn the engine over and look at the coil wire and it has no spark. I waited for a little while and when I attempted to start it up it fired right up. So what is going on with the coil? I can let it sit and idle and it will stop running after a about 10 min then let it sit and try it and it starts up again. I tried another coil (not new) and it does the same thing. While it is running it runs great. It does not have a balast resistor, to my under standing chevys have this built into the wiring. If it is built in where is it? and could it go bad? Could the coil some how be over heating if there is no balast resistor or the built in one is not working? If you have not read this is in a 67 Camaro with a 327,powerglide,points, basicly all stock.
Link to the old tread http://www.chevelles.com/forum/Forum1/HTML/004188.html
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Gold Member #164
sites.netscape.net/1969ss/homepage (http://sites.netscape.net/1969ss/homepage)
San Diego CA.


[This message has been edited by Joe Harrison (edited 09-15-99).]

[This message has been edited by Joe Harrison (edited 09-15-99).]

Joe

I'm assuming you have a points disributor.
Yep, It sounds like you are getting a full 12 volts to the coil when the ignition switch is on. If you are running a stock style points distibutor you should not be getting 12 volts at the coil, you should get around 9 volts but no more. 12 volts will overheat it. If you are indeed getting 12 and need to reduce it to 9 you can buy a balast resistor at most auto parts stores. Just connect it between the ingnition switch and the positive connector on the coil.

Did this car ever have an HEI or MSD style ignition system in it?

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Clark
TC #68
Ft. Polk, Louisiana

Does this car have points or an electronic ignition system? If it is a points distributor, you may have a bad condenser. Have you checked the point gap or dwell angle?

it does have points and has never had any modifications done to it. If the dwell is out of wack will it cause it to do this?? I never even checked it! This car has been siting for 5 years and it it has only taken me just under $75.00 to get it running, that includes doing the brakes and brake hoses buying a 2bbl carb and intake at the swapmeet and rebuilding the carb. I can't ask for it to get any cheaper than this. I can't remember but I don't think an HEI will fit in a Camaro will it. Are the pertronix modules any good that convert to electronic ignition?

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Gold Member #164
sites.netscape.net/1969ss/homepage (http://sites.netscape.net/1969ss/homepage)
San Diego CA.

Dwell would not cause your problem.
Maybe the condensor is failing as it gets hot, as described above. If you have one on the (+) coil terminal, it can be disconnected for troubleshooting as it is just a noise filter for the radio.
If it is not the coil (and it looks like you have ruled that out), and you've replaced the condensor in the distributor, and you're sure you're not getting spark, then it could only be one of two things: something is wrong at the coil's + terminal, or something is wrong at the coil's - terminal.

+ terminal: you need to see if you're getting voltage here when the car is in it failure mode. If you dont have a meter handy, carry a piece of wire with you, and when it fails, connect the wire from the coil (+) to the battery (+) and see if it starts. If it does, then you have an open somewhere between your coil and ignition switch. The "ballest resistor" is actually the wire that runs from your firewall junction to the coil, and is not just regular wire.
Something else to check also is to make sure that if you still have the wire that goes from the coil (+) to the outside terminal on the solenoid (yellow on a Chevelle), make sure that it is not shorting out against the exhaust or anything else that maybe a ground. If this were the case, you'd probably get a pretty good spark when you try to do the wiring trick that I explained above. Plese note that that trick is for troubleshooting only; if you run it very long with a full 12 V, you'll burn up your points. Also, I would connect it at the battery first, so that if there does happen to be a spark, it's at the coil rather than the battery.
If you have voltage at the coil all the time then check out the (-) terminal of the coil:
If you have a dwell meter, attach it to the (-) terminal and crank the engine. If it doesn't move, you have a short somewhere between the (-) terminal and ground: check the wire for signs of chaffing against the intake manifold, or inside the distributor cap.
If the dwell meter pegs it's needle, then the wire that is connected to the (-) terminal has an open. If you don't have a dwell meter, you can check these steps with a vom: if you have a constant 12Vdc at the (-) terminal while cranking, then there is an open. (Note: I think that even with the resistive wiring, if your points happen to be open, you will see 12Vdc on either terminal. With the points closed, you would see 0 at the (-) terminal and 9 at the (+) terminal. The reason why I bring this up is that if you measure 12 at the + terminal, don't automatically assume you don't have the right wiring). If it is constantly zero, then there is a short. You should see voltage bouncing as the points open and close. If you can make sense out of all of this, I hope it helps.

Well I got the meter on it I do have 12v to the coil at all times, the strange thing is I checked this one time a few min before and got a 9.9 to 10.1 v reading just after start up. I had also checked the battery between the pos and neg and had a reading of 13.6v after letting it run about 2 min I get a reading of 15.6v and I also get the 12v reading at the coil. If I let it run it will die, let it sit and it fires right up but dies faster (about 1/2 the amount of time). After the high charging reading I would think the voltage regulator is bad, but would this give me the high reading at the coil?

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Gold Member #164
sites.netscape.net/1969ss/homepage (http://sites.netscape.net/1969ss/homepage)
San Diego CA.




[This message has been edited by Joe Harrison (edited 09-16-99).]

Reading 9-10VDC while running is good. Reading 12 while off may have to do with my statement about the points being open: you could read 12V. I would replace the the condensor, and if that doesn't fix it, replace the wire between the points and coil, as it may have an intermittant open. Personally, with voltage at the coil when it's not running , and considering is does this with a different coil, I don't think it could be anything else.

Gene;
What about the reading of 12v at the coil while running remember it takes a minute or two to get this high reading and other times it comes right up, this reading is at the (+) side. Does this mean the balast resistor circuit is not working? If I have this high reading will burn up the points first or does it some how overheat the coil and make it stop running. I still need to do some checking on some areas like the wire to the dist. from the coil and the condensor. I just posted some pictures of the car on my web site if you want to check out the $500.00 beast.

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Gold Member #164
sites.netscape.net/1969ss/homepage (http://sites.netscape.net/1969ss/homepage)
San Diego CA.

I'm sorry, I misread your previous post...I though the voltage was 9-10 while running and 12 while in the failure mode. Maybe the high voltage is causing your problems. Have you tryed replacing the voltage regulator? 15.6 is kinda high, and is probably the cause of the high coil voltage. Any kind of ballest sysytem you have, whether its a resister or resistive wiring(which yours should be) wouldn't allow a higher voltage if it were failing; a failure in that system would cause low voltage, as it can only increase in resistance, and would usually become an open circuit.
One thing you can try is to unplug the alternator and see if it runs longer. With a fully charged battery, it should run for hours, as long as you don't use any accessories, like lights and wipers, and don't turn it off/on alot.

After looking at the pics, I'd say that even if you can only drive it in 10 minutes shots, you still got a deal.

[This message has been edited by Gene McGill (edited 09-16-99).]

Joe

If your voltage regulator is putting out 15 to 16 volts then everything including your points and coil are getting more voltage than they should. Try Gene's Idea with the alternator. Then check the voltage at the coil with motor not running but with the ignition switch on. If your still getting full battery voltage then I think you found your problem.

The "ballast resistor" is the special wire that runs from the firewall connector to your coil. Many people have replaced these wires and there is no telling what that cars history might be. If it turns out that yours has been replaced with a nonresistance wire you can simply add the resistor to your exsisting wire.

I'm really curious about this one. When you find the problem let us know.
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Clark
TC #68
Ft. Polk, Louisiana

[This message has been edited by Clark (edited 09-17-99).]