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No spark - Need help.
- Thread starter vping
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dklawson
Yoda
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You'll need to look at what's going on inside the dizzy using a multimeter while the ignition is on.
This should help.
https://home.mindspring.com/~purlawson/files/LucasPointsIgnitions.pdf
This should help.
https://home.mindspring.com/~purlawson/files/LucasPointsIgnitions.pdf
dklawson
Yoda
Offline
You mean what if you have positive ground? You're still trying to find out where the voltage (primarily on the low tension side) is "not" where its supposed to be.
Your biggest difference on a positive ground car will be where the wires connect to the coil. (i.e. On a positive ground car a Lucas coil will have the SW terminal going to the ignition SWitch and the CB terminal is connected to the points (Contact Breaker)).
Otherwise use the same troubleshooting logic just keeping in mind that any voltage measurements you make will be opposite in polarity to what I may have written in the negative ground document.
Your biggest difference on a positive ground car will be where the wires connect to the coil. (i.e. On a positive ground car a Lucas coil will have the SW terminal going to the ignition SWitch and the CB terminal is connected to the points (Contact Breaker)).
Otherwise use the same troubleshooting logic just keeping in mind that any voltage measurements you make will be opposite in polarity to what I may have written in the negative ground document.
Offline
any chance you're 180 deg out? have you set the static timing? University Motors has a video on youtube. (don't ask me how I know that's important)
at the very least start by pulling a plug and turning over the engine to see if you have spark at the plugs. If you do it's a timing issue, if not, work your way back.
you can also check spark with an induction timing gun
at the very least start by pulling a plug and turning over the engine to see if you have spark at the plugs. If you do it's a timing issue, if not, work your way back.
you can also check spark with an induction timing gun
David_DuBois
Jedi Warrior
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Vince - Check that you have the insulators and wires installed correctly on your points.
Cheers,
Cheers,
JeffS
Jedi Trainee
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If in doubt, pull the distributor. Hold an Ohm meter to ther terminal block on the side and ground (on the body). As you turn the shaft, you need to see continuity break as the points open. If not, the points are either corroded or as Dave mentioned, the insulators are in wrong or pinched.
If all that's fine, You could be 180-out with the drive gear (in the block) which will act like the distributor is bad until you get one LOUD exhaust backfire from the exhaust filling with fuel vapors. You can test that by switching the plug wires 180 at the cap.
If all that's fine, You could be 180-out with the drive gear (in the block) which will act like the distributor is bad until you get one LOUD exhaust backfire from the exhaust filling with fuel vapors. You can test that by switching the plug wires 180 at the cap.
OP
Offline
Hey Jeff. Not wanting to mess with it the exisitng one and knowing I have a perfectly rebuilt one from you with Pertronix, we decided to swap it out. I handed it to my buddy who was about to install it and I yelled "Wait!" that's negative earth. Phew! Knowing I was going to put the Pertronix in my GT, I pulled out my Points dizzy and put it in. She fired right up. It only ran for a second and there was a really loud squeal which is either Gen or Water pump.
Once we get the Dizzy we took out of the project car, rebuilt it's going back in. The one from my GT will sit on the shelf as a known, "This dizzy works". It's nice to keep spares like this around.
Thanks everyone. Off to the next diagnosis.
Once we get the Dizzy we took out of the project car, rebuilt it's going back in. The one from my GT will sit on the shelf as a known, "This dizzy works". It's nice to keep spares like this around.
Thanks everyone. Off to the next diagnosis.
emmett1010
Jedi Hopeful
Offline
I keep a spare, points distributor, in the trunk of my pertronix powered MGB.
If the pertronix unit quits, it's time for the wrecker, unless you have a back up unit.
If you leave the key on, without the engine running, at some point in time the pertronix unit will crash. I understand it to be 3 to 5 minutes, but I've never tried it!
If you must leave the key on, be sure to disconnect the dizzy power wires.
Emmett
If the pertronix unit quits, it's time for the wrecker, unless you have a back up unit.
If you leave the key on, without the engine running, at some point in time the pertronix unit will crash. I understand it to be 3 to 5 minutes, but I've never tried it!
If you must leave the key on, be sure to disconnect the dizzy power wires.
Emmett