Timing light spec's

[golf-gti-matt]

Thought i'd give my golf a tune-up following the guide on here today, i was playing around with the ignition timing (was waaay out), i set it up with my trusty gunson timing light, then thought i'd have a play with a colleagues snap-on timing light as he had never used it before!  Anyhow, say your standing infront of the car looking down the flywheel hole the timing mark is about 3mm further back towards the car with the snap-on light compared to the gunson light! How odd! which one do i belive  is it worth worrying about for that small difference?

[Ben Lessani]

I know which I'd believe

[Mew]

Do either of the lights have an adjustable advance?

Also, when you say stood in front of the car, is that where you were timing it from or was that just to explain what happens?

[golf-gti-matt]

The snap on light has a digital gauge, when set to 0 it flashes erraticly around the 6 degrees before tdc mark, when you set the gun to 6 degrees advance it flashes at the tdc timing mark this confused the 'life' out of me so i hooked up the gunson which is just a standard flashing one, no gauges or anything and the 6 degrees before tdc mark lines up perfectly with the arrow on the gearbox.  Seems to run ok aswell

[JC8V_Gti]

yeah, when you're using the snapon 1 you have to use the TDC mark i believe because it has built in advance.

[golf-gti-matt]

In which case both guns are spot on. good times!

[rubjonny]

with the snapon one you can use either mark. if set to 0 and use the BTDC mark, if set to 6deg advance use the TDC mark. simples.

[Ben Lessani]

You a meerkat now rj?

[rubjonny]

Indeed, i actually checked to see if that website existed this morning

[golf-gti-matt]

with the snapon one you can use either mark. if set to 0 and use the BTDC mark, if set to 6deg advance use the TDC mark. simples.

Yeh all makes sense now, im old skool cant be dealing with all this modern digital stuff! haha