Hyper spark???

Swedefj40

Petty Officer 1st Class
Joined
Jun 9, 2018
Messages
224
Can someone explain to me why I'm getting a hyper spark or ignition pulse on #1 & #6 wires coming off the distributer? I have a 1996 4.3LX A1G2 with thunderbolt 4 ignition.

What I mean is, I clamped my timing light to #1 wire and at idle 700 RPM (tach reading), it shows 900+ RPM with the timing light. #2, 3, 4, & 5 wires show the correct 670 (ish) RPM with the light, but #6 is showing 2000 to 3000 RPM!!! The engine is running fine but I'm really curious as to why the higher pulse numbers on #1 & #6 wires? The plug wires are only a few years old. As is the cap and rotor. Is it possible the light is picking up the pulse from the adjacent wires?

Any ideas?
 

Grub54891

Admiral
Joined
Jun 17, 2012
Messages
6,348
Move the wires away from the pickup? Are you put the pickup close to the plug or up by the cap? It should be down by the plug.
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
7,260
Can someone explain to me why I'm getting a hyper spark or ignition pulse on #1 & #6 wires coming off the distributer? I have a 1996 4.3LX A1G2 with thunderbolt 4 ignition.

What I mean is, I clamped my timing light to #1 wire and at idle 700 RPM (tach reading), it shows 900+ RPM with the timing light. #2, 3, 4, & 5 wires show the correct 670 (ish) RPM with the light, but #6 is showing 2000 to 3000 RPM!!! The engine is running fine but I'm really curious as to why the higher pulse numbers on #1 & #6 wires? The plug wires are only a few years old. As is the cap and rotor. Is it possible the light is picking up the pulse from the adjacent wires?

Any ideas?
yes or you are picking up spark scatter from the plug wires or cap despite their age. Often times when you run the wires parallel to each other you can get spark jumping wires. separate them and see if it goes away.

You didn't say you were having runnability issues so this may be an instrumentation error vs a real issue
 

Swedefj40

Petty Officer 1st Class
Joined
Jun 9, 2018
Messages
224
yes or you are picking up spark scatter from the plug wires or cap despite their age. Often times when you run the wires parallel to each other you can get spark jumping wires. separate them and see if it goes away.

You didn't say you were having runnability issues so this may be an instrumentation error vs a real issue
My guess it's inductive. I'll try and clamp the wires closer to the plug instead of the distributer.
 
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