XJS ( X27 ) 1975 - 1996 3.6 4.0 5.3 6.0

87 V12 HE Lucas Issue

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Old Apr 13, 2015 | 03:15 PM
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Default 87 V12 HE Lucas Issue

I'll try and zero this in to the issue I'm having. I've got no spark from the coil, but have 12v coming out of it tested with meter. Does the aux coil on the front grille need to be working as well in order to get spark? It only has 2 wires coming from it connected to the Lucas coil, not sure how to even test it. A little stumped here.
 
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Old Apr 13, 2015 | 03:41 PM
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Yeah they should both be working. You only have 12v while cranking on the one?
 
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Old Apr 13, 2015 | 04:13 PM
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Yes, give me a sec I'll post a video.
 
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Old Apr 13, 2015 | 04:56 PM
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This video should answer your questions, hopefully it will help answer mine, you can view it here
 
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Old Apr 13, 2015 | 07:34 PM
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The second coil is only to add extra energy at high revs the single coil can not recover quick enough to build up a good spark at high revs hence the additional primary, The ignition amp switch's the coils by grounding them or switching the negative so 12v at the coils is normal, you need to check the wiring and pick-up inside the distributor and the amp inside the ignition unit this is a standard GM product and available anywhere


good luck
 
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Old Apr 14, 2015 | 01:28 AM
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Originally Posted by sidescrollin
Yeah they should both be working. You only have 12v while cranking on the one?
SS

The Lucas car will start quite Ok on just one coil. It is only over about 3,000 RPM that the second one is essential.

Greg
 
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Old Apr 14, 2015 | 01:33 AM
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Originally Posted by mrtalkradio
I'll try and zero this in to the issue I'm having. I've got no spark from the coil, but have 12v coming out of it tested with meter. Does the aux coil on the front grille need to be working as well in order to get spark? It only has 2 wires coming from it connected to the Lucas coil, not sure how to even test it. A little stumped here.
In addition to the other things guys have mentioned, check all the wires to their connectors are OK. the copper wire sometimes actually breaks just at the connector but because of the connector insulation it appears intact.

If you have 12v going into the coil, and no spark coming out, and the negative side of the coil is connected Ok to the amp, then I would start with the amp, and also very important, check the connecting plug to the shielded wire that runs from the amp back into the loom that goes to the ECU.

Greg
 
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Old Apr 14, 2015 | 04:31 PM
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Default 87 HE Update

Thanks for the help fellas. Found the biggest critter nest I've seen to date. There are numerous wires chewed through, including the 2 that connect to the inside of the distributor. I've taken pics, and a video. Hopefully this is the issue. Finding that wiring piece that's inside the distributor is going to be fun, idea on what's its props name and function are?












 
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Old Apr 15, 2015 | 10:43 AM
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Haha that sucks. That is what the inside of the bellhousing on my MGB was filled with when I got it.
 
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Old Apr 15, 2015 | 10:49 AM
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Originally Posted by Greg in France
SS

The Lucas car will start quite Ok on just one coil. It is only over about 3,000 RPM that the second one is essential.

Greg
yeah my bad, I don't know how much is used. I mostly meant that they should both definitely be working, not that both are required to start or anything like that
 
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Old Apr 15, 2015 | 03:44 PM
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Default 87 HE crank no start

The wires that were chewed through are the 2 that connect inside the distributor on one end, and come out of the black connecting clip on the ignition amplifier. I believe this is my issue, we will see.

Edutainment Video One Here
Informational Video Here
Miracle Video Here
 
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Old Apr 17, 2015 | 04:12 AM
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That did it, car is running once again.
 
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