Any idea why a distributor wouldn’t spark in the chilly mornings but the same afternoon when it warms up a little starts up just fine? My ignition box and coil were tested and work fine btw.
Have you checked your distributor cap for moisture? It might condense overnight, but evaporate when things warm up. How old is the cap/rotor?
And what make/model/year/miles is the car?
Welcome Breakfaststout. +1 for texases.
When it does start…get a spray bottle of water. Then one ignition part at a time…spray that part with water. After each component - try to start the car. When car doesn’t start - the last ignition part you sprayed is most likely the culprit…replace that part.
I’ve looked under the cap in the morning and never saw any condensation. I just replaced the cap a week ago. Replacing the rotor next. If that doesn’t fix it, i guess I’ll have to shell out $$$ for a better distributor.
This is a 89 ramcharger project truck btw. Swapped a 390 magnum and carbed it. I’m switching over to a 12v ignition system from the 6v ballast resistor setup. The distributor is the only 6v component left. It runs during the day like a champ, it just won’t spark in the morning. The box and coil are both 12v.
How about the spark plug wires and plugs? How old are those? And the ballast? I’d hold off replacing the distributor, there’s no reason this can’t be fixed with some much cheaper parts.
New plugs and wires. I haven’t had the resistor in it for a year now. Figured I’d just keep replacing the cheap cap and rotor if they burned up.
Always replace the cap and rotor as a pair.
I take you mean you have a 360 Magnum engine, right? Are you swapping from points to electronic ignition?
Have a cap and rotor on order now. Yes it’s a magnum engine. Electric ignition.
1972 was the last year for points on a Chrysler V8.
Why is there a ballast resistor? Are you using the stock ignition system from the new engine?
Tried to save some money by buying the ignition kit from proform. Comes with a distributor, box, resistor. Bought coil separately. Chrysler’s ignitions used resistors to take the voltage down to 6 volts. I wished i would have just spent the money on a better 12v distributor, but they are so expensive. I’ve replaced the box and coil with 12v components. Haven’t replaced the distributor yet because it still seems to work fine, just not in the mornings or when its cold outside.
Do you mean the engine starts and run in the afternoon when the ambient temp is warm, but won’t start and run when the ambient temp is cold? That might not have anything to do with the distributor. Explain a little more what you mean by the “distributor won’t spark”?
The distributor won’t tell the box to fire in the mornings. If i take the coil wire off the distributor and try to start it, i get no spark off a metal surface. The engine turns over fine, i just get no ignition spark. I tested the box and coil by jumping the distributor wires. Sparks everytime.
May I ask how you are getting 6vdc to the 6vdc parts of the ignition that need it? Er wait what am I asking… You have a mixture of 12v and 6v ignition components? How exactly are you getting the proper dc voltage where you need it? I’m confused
Ok I read your post describing this… perhaps this is the problem though? Test your voltages to see if it is functioning properly.
That’s the function of the ballast resistor. All voltages appear fine, granted i tested them during the day. I’m replacing the 6v proform ignition kit i bought which mimics old chrysler ignition systems. The distributor is the last component left and where the problem is. I haven’t used the ballast resistor at all. I was trying to get a better spark to the plugs. The only thing as far as i know should wear out because of that should be the cap and rotor. Already replaced the cap. Rotor is on order. The main question here us how a temperature/ humidity deference can cause the distributor not to tell the box to spark. Like i said before, it starts and runs with absolutely no problem during the day. I’ll post again after the rotor gets installed. If that don’t fix it, a $250 msd distributor should.
Well proform just informed me that my distributor is in fact a 12v distributor. So i can rule out the whole 6v - 12v part mixing issue. I’ll post again when the rotor gets here and see if that makes a difference.
The common distributor from the 60’s 70’s had breaker points driven open and closed by the distributor cam (the rotating shaft in the center of the distributor). The sparks were distributed to the spark plugs by the ignition rotor. That type of distributor used 12 volts to the coil primary during cranking, but a lower voltage to the coil primary during running. This was done to extend the life of the points and the coil. The common distributors in the 80’s however still had the ignition rotor going round in circles to send the spark from the coil to the spark plugs, but didn’t use breaker points. This type of ignition system used transistors instead of the breaker points. So they didn’t need to worry about burning any breaker points out with too high of voltage. The transistors and the coil on this type could handle the full 12 volts all the time.
A distributor isn’t really classified as 6 volts or 12 volts. That a spec for points and coil, or the input voltage requirement to the ignition module. If your ignition module input voltage is correct, the problem is likely either a grounding problem for the ignition module or distributor, a faulty coil, or whatever triggers the ignition module isn’t working for some reason. On 80’s distributors there’s often a sensor or sensors inside the distributor that senses the rotation of the distributor shaft. That is what triggers the ignition module to produce a spark at the right time. There’s a spec for the gap between the sensor and the distributor shaft. If that gap is too large, this symptom could result. Likewise if the input voltage to the ignition module is too low.
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Thanks for all the info. I replaced the rotor and it seems to have fixed the problem.
Rotor didn’t fully fix it. Adjusted distributor air gap and it fired right up this chilly morning with no hesitation. I hope this is the source of the problem, but time will tell.