Timing gun changes RPM when trigged pulled

[74superTN]

So my timing light makes my engine rev higher when I pull the trigger to check timing...Any reason why this is? I can't get a good time on it if it's revving it higher....Type IV, Electronic Distributor, Weber 40's
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73 Thing
80 Vanagon Westy

[Starbucket]

Is the timing light new? Some new ones you can set the advance or something like that so read the instruction manual or look at the gun for something strange.

[74superTN]

[74superTN]

Not to mention, when I set it with a static light, the location changes...I can hook the light up to a ground and then negative terminal on the coil and each time I do it, I can turn the distributor completely in a circle without it lighting up, then all of a sudden the red bulb will light. i'm so confused
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73 Thing
80 Vanagon Westy

[Wildthings]

[Abscate]

Is it inductive pickup or pass through?
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.ssS!

[busdaddy]

[74superTN]

[busdaddy]

[WhirledTraveller]

Attach the red to the battery +

Sounds like you are affecting the spark by attaching at the coil.

All that a basic timing light needs is 12v power (the black and red alligator clips) and a signal from the clamp over the #1 spark plug wire.
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1977 Westy, Automatic. Big Valve heads, CS Cam.

[busdaddy]

[timvw7476]

If you have a timing light/gun with three leads,use the battery posts for
+ & - & clip the inductive clamp around the #1 spark plug wire, if the
strobe light seems to misfire you may have to move the inductive clamp
up or down the wire to lose a false signal from one of the other plug wires.

[Amskeptic]

[74superTN]

It's a Petronix Distributor and the strobe doesn't seem to misfire, it just speeds up my motor when I pull the trigger. It's a three cable gun, red, black, and the one that goes on the #1 spark plug wire. I put red on the positive coil, black on a ground on the engine, and the other on the spark plug wire. Right now all it's doing is trying to crank, I can't actually get it idling and this all of a sudden happen within two days. No to mention when I did get it running for a second yesterday, I had no spark on #1
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73 Thing
80 Vanagon Westy

[74superTN]

And here's the light I'm using
https://shop.advanceautoparts.com/p/actron-inductive-timing-light-cp7527/9090009-P
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73 Thing
80 Vanagon Westy

[tommu]

The manual says

[Abscate]

[74superTN]

Also, this is in a Vanagon, so I can't reach the battery terminals.
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73 Thing
80 Vanagon Westy

[TomWesty]

[Wildthings]