trouble shooting weak ignition spark !!! Help
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Topic author - Posts: 73
- Joined: Sun May 05, 2019 8:50 am
- First Name: David
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trouble shooting weak ignition spark !!! Help
Well I have been working on a non starter 1917 for a month Zero compression, no spark Now with valve and ring job, new wiring, rebuilt coils still no start I have narrowed it down to a very weak visible spark when I lay the plugs on the block and rotate the cylinders into firing order . I have read on the forum years past that a weak spark visible on a plug OUTSIDE the block will result in no spark when the spark plug is chambered and under pressure. I am using modern F 11 plugs new, set at 032 I have strong coil noise New spark plug wires, The only thing I may think of since this is a non starter car is I used 12 gauge wire for both the 12 volt battery ground and running up to the ignition switch Could this thin wire not carry enough amperage ?? Any ideas ?
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Re: trouble shooting weak ignition spark !!! Help
What kind of shape is your coil box and switch in? Maybe some carbon tracking or some other kind of resistance holding back a decent spark?
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Re: trouble shooting weak ignition spark !!! Help
Professionally rebuilt coils or .......?
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Re: trouble shooting weak ignition spark !!! Help
Hal's question as well, plus, are your spark plug wires copper conductors soldered to their terminations, or are they modern carbon-filled wires?
Scott Conger
Tyranny under the guise of law is still Tyranny
NH Full Flow Float Valves
Obsolete carburetor parts manufactured
Tyranny under the guise of law is still Tyranny
NH Full Flow Float Valves
Obsolete carburetor parts manufactured
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Re: trouble shooting weak ignition spark !!! Help
I suspect the gap. My antiques do well with about a .022 gap. Might be worth a try. Hope this helps, and good luck! Cheers, Bill
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Re: trouble shooting weak ignition spark !!! Help
Not sure about the wire size as it doesn't take much to fire the coils but, as mentioned earlier, "rebuilt coils" ? Done by who and were they properly set up on a HCCT or similar unit? If they weren't it's probably a big part of your spark problem. It simply MUST be done. No question. If they were done correctly run a larger size temporary wire to the coil box and check for a difference. Disconnect the coil box wire first though. A poor ground is another thing to check as in a clean timer. It's as bad as low voltage. I's also try a smaller plug gap. 0.30 for instance.
Forget everything you thought you knew.