Wits end, V8 ignition

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Farx4

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Wits end, V8 ignition
« on: June 20, 2018, 10:12:59 PM »
Why would an elctronic ignition system give 4-5 really healthy sparks and then nothing? Leave it for a while and it will do the same again. All parts including coil, leads and ignition module are new. Coil has been tested and the module has been replaced for another by the manufacturer and gives the same symptoms as before.

Have no idea where to go from here so gratefull for any serious suggestions or anyone who could help >:(

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Navigator

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  • Name: Stuart Clink
Re: Wits end, V8 ignition
« Reply #1 on: June 21, 2018, 08:41:51 AM »
Perhaps it IS giving more sparks but they are going somewhere else due to insulation breaking down somewhere. Or a duff wire stops passing power to the unit after the initial load?

I would try bench running the unit away from the vehicle completely. Even remove the distributer (or use a spare) and turn it by winding a bit of string on the shaft (like a lawnmower pull start) to check what is happening.
Navigator          GM1VBE

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rangerovering

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Re: Wits end, V8 ignition
« Reply #2 on: June 21, 2018, 09:33:35 AM »
Is it electronic ignition? Lucas dizzy? Could be the hall sensor breaking down in the baseplate, do a resistance check on the 2 pins without the module connected and see what readings you get. I can dig out a few links to get the right figures.
Steve




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Farx4

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Re: Wits end, V8 ignition
« Reply #3 on: June 21, 2018, 06:27:51 PM »
It's a Mallory distributor converted from twin points to electronic ignition with a Powerspark module, new Viper dry coil and Ht leads. Ballast resistor has been removed as per the fitting instructions. I think that the problem lies elsewhere in the wiring so I am going to work through it. Where should the earth from the coil go to? The ignition side of the loom is from the original V8 90 donor vehicle. Can I run a seperate earth fromthe coil and if so where should it go to?

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discoverypete

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  • Name: Peter Williamson
Re: Wits end, V8 ignition
« Reply #4 on: June 21, 2018, 08:35:23 PM »
You say where does the earth from the coil go to?
The positive side of the coil goes to the ignition switch.
The negative side goes to the ignition amplifier module. What used to be the points.
The rev counter is also on the negative side of the coil.
It is important to get the coil the right way round as there is an internal ballast on the positive side, inside the coil.
The suppressor /condenser is often a problem (if fitted) as they don't make them like they used to.
Run the earth wire from the distributer to a good earth or back to the battery if its in the engine bay.
I had electronic ignition on my old car and had problems getting a good suppressor, it would work on the points system but not with the electronic system. I tried three or four before I got one to work.
Good luck.

                   Pete.
There must be a Powerspark wiring diagram on the internet. That would help.

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Farx4

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Re: Wits end, V8 ignition
« Reply #5 on: June 21, 2018, 09:28:41 PM »
Thanks Pete. The only earth wire from the distributor is the one that comes from the electronic ignition module. Tried earthing the baseplate of the distributor as Powerspark suggest. No condensor or ballast resistor in the circuit. So it has to be either on the ignnition switch to coil circuit or on the engine or vehicle main earth that the problem lies. There aren't many wires on the vehicle so I stand a fighting chance.....I hope.

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discoverypete

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  • Name: Peter Williamson
Re: Wits end, V8 ignition
« Reply #6 on: June 22, 2018, 01:40:12 PM »
Keep us posted.

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Farx4

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Re: Wits end, V8 ignition
« Reply #7 on: July 02, 2018, 09:19:33 PM »
Eventually gave up with the electronic ignition kit and sent everything back. Refitted dual points, set the gap and timing and it fired up first time...........ran for a while sweetly then ran lumpy again with a hot coil. Coil has been replaced ( ballasted version) new Mallory condensor and new spark plugs on their way. Before I fit all this latest stuff and set the gaps again and timing I need to get my head around why the coil is geettin so hot. Any suggestions?

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cooltshirt

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Re: Wits end, V8 ignition
« Reply #8 on: July 03, 2018, 05:47:51 PM »
Hi
I had a 110V8 ........ suggest ditch the ballast resistor and fit a DLB198 coil.
Also you could phone these guys http://www.realsteel.co.uk/ They know lots and lots!
The coil will get very hot ............ The lumpyness could be timing ........ you need lots of advance, I think I had 38 degs when it was up to 2500rpm+. Just keep advancing until in pinks!
Good luck!
1983 110 V8. RIP