timing light dramas

Hey guys, having issues with getting timing fluctuations with a snapon light however a cheaper alternative reads perfect, running 4 ls1 coils and im curious as to whether the snapon may be more sensitive to electrical noise also if its anything to be concerned about. Its fluctuating 10-15 degrees at idle with the timing lock on however its reading spot on with the cheap light. Cheers

how are you attaching your inductive clamp? is it on the loom to the coils or a flying lead between coil and plug?

Sometimes the elctronics get confused with coil on plug setups in those fancy timing adjustable guns. Its always good to have two, Standard non-advance timing gun and an advance one. Also Good to have the timing signal of a plug wire or a spark plug lead in between the coil and the plug that you can make out of spark wires.

i was clamping onto the high tension lead. i havent had an oscilloscope on it but it seems to be running too well for the readings from the snapon light to be correct.

I've got a snap-on dial back timing light and a cheapy optilux. There is the occasional time when I get interference with the snap-on that the optilux seems immune to. I don't believe I've ever seen this issue when clamping to the actual ignition lead though. One thing that trips people up is if you're running the ignition system in waste spark and trying to use the dial back function - This won't work as the timing light is seeing double the sparks it should be for a given rpm and hence can't calculate the correct offset.

Cheers for the reply, im running sequential ignition and the dial back function wasnt being used. Would you agree that if im getting perfect readings from the other light that it must be an issue with the snapon? Or possibly still a faylt with the ignition system

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The dial back timing lights do seem to be a little more susceptible to interference than a more basic timing light. i generally don't have any trouble with my own snap-on light and it pretty much either works or it doesn't. Given your situation I'd say there is every chance there is a problem with your timing light. It might pay to get it checked out.