Thunderbolt 4 no spark Baffled

patalbcas · Jul 25, 2012

Thunderbolt 4 ing no spark.
new plugs ,wires,coil,module.dissconected tach and shift cut out switch. spark during test jumps from neg coil too center tower 12 volts at pos coil and dist.
HELP

Don S · Jul 25, 2012

Re: Thunderbolt 4 no spark Baffled

Follow this chart to find the problem.

patalbcas · Jul 25, 2012

Re: Thunderbolt 4 no spark Baffled

Don S said:
Follow this chart to find the problem.

View attachment 160534

Thanks for your reply
I did this check and when i tap the wire i get spark from neg coil term to center coil post, nothing at spark tester.
I am usein a ground from battery during test. why is spark jumping on coil?
Pat

Don S · Jul 25, 2012

Re: Thunderbolt 4 no spark Baffled

Could be a bad coil wire. The one from the center of the coil that you have going to the spark tester. You do have your spark tester hooked to a good clean ground don't you?

patalbcas · Jul 25, 2012

Re: Thunderbolt 4 no spark Baffled

Don S said:
Could be a bad coil wire. The one from the center of the coil that you have going to the spark tester. You do have your spark tester hooked to a good clean ground don't you?

I have tryed the new coil wire and a spare i bought and yes using ground from battery for spark test

patalbcas · Jul 25, 2012

Re: Thunderbolt 4 no spark Baffled

Don S said:
Could be a bad coil wire. The one from the center of the coil that you have going to the spark tester. You do have your spark tester hooked to a good clean ground don't you?

could it be a bad distributer sensor?

markheck1 · Jul 25, 2012

Re: Thunderbolt 4 no spark Baffled

Did it lose spark for no apparent reason, or was it after you replaced these things?

Pete104 · Jul 25, 2012

Re: Thunderbolt 4 no spark Baffled

Are you cranking it from the dash? Pull the cannon plug & try hot wiring it.

patalbcas · Jul 26, 2012

Re: Thunderbolt 4 no spark Baffled

The boat was running fine on;y would backfire through the carb after 20 mins of cruising.
so I thought the coil was failing after it got hot so I changed that and motor ran very rough at start up.
so I changed the plugs and wires and rebuilt the carb, added fresh gas and fuel filters.Then when I tryed starting it ,no spark.
so I used the chart to test ign system and thought I had a bad module/amp,replaced that and dissconected the tach and shift cutout switch. used a ground from the battery and retested,still the only spark I get is from neg term on coil to center post.
Buying a new meter today to make sure I am getting a full 12v to coil, I had a cheap meter that was hard to read. Maybe I'm only getting 10 v to coil?
Pat

markheck1 · Jul 26, 2012

Re: Thunderbolt 4 no spark Baffled

Is it the right coil?, not sure but I know there are resistor and non resistor wire coils and stuff.....I'll probably need to figure this out someday since I too have a T-IV system on mine

Failproof · Jul 26, 2012

Re: Thunderbolt 4 no spark Baffled

If its jumping from neg to center terminal on coil, then that is the path of least resistance. Posible crack in the coil tower? Missing/bad rotor? Cap needs replaced? Rotor button broken/missing? Coil wire(distribution wire)then high resistance/bad end/wrong style end? If the coil is arching to negative with the coil wire on, then you need to look for cracks, clean, and use dielectric grease and retest.

patalbcas · Jul 26, 2012

Re: Thunderbolt 4 no spark Baffled

Yes it the correct coil for an HEI system and yes they are diffrent.

patalbcas · Jul 26, 2012

Re: Thunderbolt 4 no spark Baffled

Coil is brand new but I did inspect and put the dielectric grease on it, I am not turning motor over during spark test so cap/rotor/sensor not an issue, just trying to get spark to tester from the distributor wire to ground as discribed in the flow chart

patalbcas · Jul 26, 2012

Re: Thunderbolt 4 no spark Baffled

I just read that you can fix a hairline coil crack with nail polish,is this true?

Dags1213 · Sep 11, 2012

Re: Thunderbolt 4 no spark Baffled

patalbcas said:
I just read that you can fix a hairline coil crack with nail polish,is this true?

Hey....I have the same problem....did you ever get it fixxed?? please let me know.

Thanks

Don S · Sep 11, 2012

Re: Thunderbolt 4 no spark Baffled

Doesn't make any difference if he fixed his or not, the cause of his problem may not be what is causing your problem.

Best to start a new thread of your own, with your problems, and your engine information. Then you will receive answers to Your problem.

Thunderbolt 4 no spark Baffled

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