lost spark

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fonzy

fonzy

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ok, well while getting ready to adjust the distributor the old valiant wouldn't start....checked for spark, none....it has an electronic ignition update, from a 76 I believe.(at least the ignition module is from a 67). checked the coil, checked the coil wire, checked the ground and positive wire on coil, all looked good. replaced the ignition module. the auto store guy spoke of a ground strap, I bought it for 5 bucks, can't find it on the valiant(225 slant six, original motor) I have a pic of the ignition module. wondering if we didn't screw up something in the distributor. have a pic. if anyone has any suggestions please, I need some help on this one. thanks fellas.
 

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So that orange box is your new one? Mounted in same location as the old one? I know Ive had those things go flaky on me. When you say you checked the wires, you checked for 12V with key on at ballast and coil? Also it was running, and just now quit? Or has it been a while since fired up?
 
The reluctor air gap should be 0.006. Those are picky, if that is the original pickup coil sometimes many years of the vacuum advance moving the contact plate breaks the wires inside the insulation to the point of higher resistance.
 
The ballast resistor was broken. Battery is down charging gonna try it after charges. Wish me luck and thanks for the responses guys. The orange module is the original.
 
BALLAST RESISTOR!!!!! Lol..whew..well I learned something today. Thanks guys. Looks like the timing will be checked tomorrow.
 
While we're on the subject, Here's another nugget. NEVER use a steel feeler gauge to check reluctor gap in a Mopar electronic distributor. .008" brass only please. Anything else will magnetize the reluctor and you won't get a pulse strong enough to fire the ignition...
 
grumpuscreature said:
While we're on the subject, Here's another nugget. NEVER use a steel feeler gauge to check reluctor gap in a Mopar electronic distributor. .008" brass only please. Anything else will magnetize the reluctor and you won't get a pulse strong enough to fire the ignition...
Click to expand...

I forgot to mention that! They used to come with a plastic feeler gauge and often I'd just use a piece of thin cardboard.
 
To the OP. Are you in the habit of leaving the key "on" with the engine off? This might be part of the cause. Are you using a high performance coil?
 
Leaving the ignition powered when the engine is not running can fry the ECU module, many say. Must be a 2-ballast setup (I think 1976 was) and the ECU ballast (5 ohm) had failed. Otherwise, it still would have sparked while cranking since the coil ballast (0.5 ohm) is bypassed.
 
no i don't leave the key on, with the engine off. it was a very old resistor more than likely, the orange box is the ignition module for a 76, the car and engine is a 66. i am not certain if it's a hot coil or not, it is a super stock ignition coil if that helps. and if this was f.b. i would like the response from mguner, i am guessing mosinitis is a love of the nagant rifle?
 
the ballast resistor is on the firewall, my understanding is at ignition it allows full battery to the coil, and while normally running it lowers the voltage to the coil. to help keep it from over heating? i am at work but tomorrow i will post a pic, also from what i have read, most people that have them keep a few spares in the glove box because they break easily.
 
Fonzy, I was kidding. I know what they are. I wouldn't run an orange box or a ballast resistor on a bet. My coil hasn't overheated in over a decade. I run an MSD box and nixed the ballast resistor.
 
roccodart, I may be doing the same soon. After "fixing" it, it runs fine, then just suddenly shuts off like I turned off the key. This happens while idling, it gave a slight shudder 2 or three times, not bad if I wasn't watching the motor I probably wouldn't have noticed it, then it just shuts off. It then won't start, after a few minutes letting it sit it starts. My pop even tried some starting fluid to see if it would start and nothing. the car idles fine, not rough, runs fine, then when it drops to idle it dies. tried bumping up the idle, no good. fuel is going into the carb. it really seems like something electrical is overheating then when it cools it fires again. Any ideas guys? I personally am not looking at vacuum because it idles fine...am I wrong? thanks again. work in progress and really leaning towards upgrading and replacing all the fuel and ignition components before they become issues in the future.
 
Temp wire a monitor voltmeter or even a lamp on the ignition feed to the ballast. See if you lose power there when it dies. Try to determine if it's fuel or spark. With it running "do stuff" like wiggle the ignition system connectors, the bulkhead connector, the switch, and the switch connector. ONE VERY TROUBLESOME point for me in the past on my old Mopar powered Landcruiser was the distributor connector
 
oh, and when we tried to advance the timing to TDC the car wouldn't start, so we went back to the -10. it fired right up...it doesn't act like it's slipped a timing belt. not the way it idles, plus that wouldn't cause this type of stall. would it?
 
My 72 Charger would do as you describe until I repared a couple of the spade terminals in the bulkhead connector on the firewall. I think one was black with a yellow stripe and of course the other was the 10 ga supply circuit.
 
67dart273, that is a good idea...I wonder if that ballast resistor could have a bad wire or simply overheat and do what is seems to be doing...I ohmed it out, but that was fine, I have not checked voltage coming out of it. I will give that a shot. thanks.
 
I was going to start checking for corrosion on the terminals as well mgunner, that is another thing I should have done just in general anyway. seems like I get ahead of myself. thanks for a place to start.
 
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