Ignition sparks as soon as starter stops cranking

T

tkvoice

Cadet
Joined
Jun 26, 2010
Messages
25
I noticed a weird behavior on my 4.3L TKS V6
The engine never starts if I keep the starter cranking. As soon as I stop cranking it starts.

I installed one of those spark tester lights on my distributor cap and it confirmed what I just explained above.... No light until I stop cranking. As soon as I stop the light bulb starts flashing and engine starts.

My question: Is this normal behavior? Or should it be sparking while starter is cranking?

If it's supposed to spark while cranking what would cause it not to spark?
 
alldodge

alldodge

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Mar 8, 2009
Messages
43,243
Not knowing your motor serial number but having TKS carb you most likely have EST ignition

Check to see if you have 12V at the coil when cranking
If not look at the key switch
 
Grub54891

Grub54891

Admiral
Joined
Jun 17, 2012
Messages
6,286
As stated, if the battery is compromise, it takes a lot of the power away from the ignition. Had a motorcycle that would not start with the starter, but one kick on the foot starter it would fire right up. A proper battery solved the issue. And yes the ignition switch can cause that also, not making the correct contact in the starter mode. Stick a meter at the coil and read the voltage when cranking, a second person will help on that one.
 
Scott Danforth

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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tkvoice said:
The engine never starts if I keep the starter cranking. As soon as I stop cranking it starts.
Click to expand...
classic symptom of bad key switch. confirm with your test meter that you have power to the purple wire during cranking. if yes, keep looking, if no, buy a new key switch.
 
C

cyclops222

Commander
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Mar 21, 2024
Messages
2,786
If your motor has a big connector plug and socket above the motor ? Reconnect the socket 3 or 4 times to improve pin and socket resistances. Worked on my TKS 5.0L Same symptoms with the key switch,
 
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