73 318 car was hard to start when hot now will not fire at all. replaced the ballast resister and the pickup in the dizzy. had the ecu tested at advance and the coil checked they said it was all good. i have power to the positive side of the coil when the switch is on but no fire out of the big wire in the center to the dist cap. what am i missing? all parts good but not firing???:spiderma:
no fire
- Thread starter rigrunner
- Start date
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cuda65vpt
cuda65vpt
OBVIOUSLY, something is not good. I suspect the coil.
ok the distributor is new tried the ecu then a coil still no start occasionaly it will try to fire when i let off the key andy ideas please? could i have a prob with my switch? how much trouble to add another ignition and do away with all this?
nothingbutdarts
Well-Known Member
Wiring/ign. switch issues. You should be getting battery voltage at the coil + when the engine is cranking over! Are you?
If you get one spark when you release the key to the run position the ignition switch could be the fault and it could be the ballast resistor or its connections. Check those terminals too.
I posted a pic of a 73 model wiring harness failure in another members parts wanted thread. Those kind of failures come and go with heat too. Use a volt meter to verify 12 volts. Much less than 12 will light up a test light and fool you. Hope this helps
I posted a pic of a 73 model wiring harness failure in another members parts wanted thread. Those kind of failures come and go with heat too. Use a volt meter to verify 12 volts. Much less than 12 will light up a test light and fool you. Hope this helps
805moparkid
Slant and AFX Guy
theres ur problem... one should be hot and the other should groung on and off...
have voltage to the + side of the coil when cranking and rechecked the - side is grounded it doesnt go off and on like i think it should. all the connections look good im stumpt. had to give it up this evening too much. is there a way to get around the switch to see if its the culprit? checked with some local shops and no one wants to work on a mopar. will try again tommorow thanks for all the help.
67Dart273
Well-Known Member
Sounds like distributor pickup/ ECU problem.
Just so ya know, you can NOT reliably check a coil with an ohmeter or any other low voltage tests. The secondary could be arcing to ground internally, for example, and you would never show the fault, even with a 500V megger, possibly
pulled the distribuor spun it by hand with the switch on and then again with the starter disabled as suggested by another member. found i have good fire coming from the coil if i spin the dist pretty fast. put it all back together and crank it over with the starter and no fire. totally lost here
68dodge
Well-Known Member
If this has a 4 pole ballast resister, try another ballast resister. I have seen these go bad on a start up. If that does not work go with a new ECU, ect.. these are a simple system. If you have 12 volt power on the start mode on the out going side of the resister to the coil and 12 volts on the power inlet to the resister from the key when its on run, which is the ignition side the power side is ok. That narrows it down to a bad ECU, coil or bad pick-up in the distributor. I would replace one at a time with new. To me it sounds like a bad ECU.
So what you are reporting is the ignition system works when the starter isn't using up the available power ? Was the ignition switch held in the start position while the dist' was operated by hand ?
yes the switch was being held in the start position when i turned the distributor and got great fire. put the dizzy back in and tried it with the starter and got no spark. first thing i replaced the ecu and then tried a new coil. when that didnt work i put a new pick up in the new distributor and still nothing. going out of town will be gone prob 5 days so ill have some time to think about it. any more sugestions welcomed im willing to try almost anything at this point. thank you all for your imput it is geratly appreciated.
i also put in a spare ballast resister and when that didnt work i ran a hot wire to the pos side of the coil from the battery and no change. my starter is a little weak but has always started could it be pulling juice away from the ecu when trying to crank it?
And we are sure the engine turns the distributor. Just for grins. Unhook the battery neg cable. Remove all 3 wires from the alternator and insulate/isolate them so they dont short to anything, hook the battery back up and try to start it. If it starts you have a short circuit inside the alternator. If it doesn't start, have a safe trip, pick up a multi meter while you're out and we'll look again.
unhooked the alternator and still no fire. i can pull the dizzy and turn by hand it fires great and put the dizzy back in and turn the body no fire. crank it over no fire pull it out spin it i have fire. could it be the dizzy itself is bad. i replaced the pick up in it and it didnt change anything. thanks.
nothingbutdarts
Well-Known Member
It's strange that it works when you have it out and quits when you put it back in. As mentioned I'm wondering if the pick-up is shorted to the case? Or if there is a wire in the harness to the ECM from the dist that has an intermittent open in it and connects when you have the dist. raised.
It will be very interesting to see if the rebuilt dist. will cure the problem.
slant6/4speed
Well-Known Member
How did you adjust the air gap on the pick up coil?
slant6/4speed
Well-Known Member
You might have a shorted pick up coil wire when you replaced the pick up coil. That way it will work when you hold it in your hand but not when it is on the engine
gonna try a dizzy in the am will let yall know what happens. strangest thing ive ever seen. if nothing else would trying a different ignition like msd work by just not using the original stuff? thanks to all for the help
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