16v ignition timing problem

[GeordieChap]

Just trying to step up the ignition timing on my 1.8 16v using a timing light seem to the get the marks to line up and then all of a sudden the engine revs go right up and the marks don't align anyone had the same problem?

[notenoughtime]

does it normally rev on its own?

When the revs rise timing alters so marks will be different

[GeordieChap]

Yeah car revs fine just idles a bit high and there is a slight backfire on down rev so was going to sort timing then idle and check co, just can't understand why all of a sudden the marks align and then off go the revs

[raferackstraw]

let car warm up, fan should come on twice, then auxillaries off, use the timing light. 6deg btdc.
if it idling high look at bypass screw/isv
search for 16v idling and there are quite a few posts.
also look at mixture/overun cutoff valve

[Gambit]

and make sure the red wire at the coil is disconnected while setting timing, co% & idle

[GeordieChap]

So it's not only the plug to the ISV I disconnect its also the red wire? Or just the red wire?

[GeordieChap]

Sorry I meant to say to adjust the idle and co

[Gambit]

Just the red wire.