Static ignition timing with lamp

[gav p]

Having had the distributor off, I've attempted to set the static ignition timing 5deg BTDC using a test lamp. Apparently this can be done by connecting the lamp between No.1 terminal of the coil and to earth, then checking when the lamp goes out (points opening) whilst rotating the dizzy slightly.

However, the lamp is out whether the points are closed or open. (Yes I checked the bulb...) I'm therefore guessing there must be no power going to the coil. Could be due to the wiring in the engine bay being a bit passed its best... anyone know how to check the coil power supply is OK?.. Presumably one of the wires on the other side of the coil is the supply for this?

Cheers,

Gavin

[Barry]

Gav, firstly make sure your test lamp is small, just one or two watts ideally, if its too big, the bulb won't light: something to do with the 'workings' of the coil I gather. Double check you're putting your lead between earth and the negative/contact side of the coil. Bulb should light as contacts open, i.e at the timing point, be out while contacts closed (because the contacts are dropping the current to earth, so no current to light your bulb).

If you are going on to use a strobe (recomended), then don't sweat this too much: if you have problems, just take the king lead off of the distributor cap, put it onto a spare plug resting on a good earth, and turn the engine over (with rotor arm pointing nearest to number one pickup on dizzy cap) whilst looking at the timing mark. You will hear the spark fire, and if you are within a couple of degrees, that will be close enough to start the dynamic timing with the strobe.

PLEASE NOTE: I HAVE CHANGED THIS FROM SUNDAY'S FIRST POST! (As first typed, car could have started whilst being turned manually )

HTH

[Barry]

Also ...

You could just put a voltmeter across the points (cheap ones start around £5.00), when the voltage goes from zero to battery voltage, the points have just 'fired'. BTW, if you get a voltage across the points, even when they are closed then your points are suspect: clean or replace.

[Barry]

Got another one ( ), put engine at your 5deg BTDC, pull number one plug lead off, put onto spare, earthed plug. Loosen dizzy, and rotate body against rotor arm rotation until number one plug fires: reclamp dizzy.

Thats it, I've finished now.

Footnote: the nice thing about this method is that, other then the spanner for the dizzy, no tools/lights/meters required .

[impmad2000]

I was worrying about this, and so checked on the CDi circuit. The points are fed via a resistor in the CDi box, which limits the points current, and so reduces the size of the bulb you can use. Use a very low watt bulb (2W or less) or perhaps a 12V LED (Can be bought from car accesory shops for use with alarms).
Tim

[gav p]

Great, thanks chaps. Will be giving these a go..

See you on sunday...

[Barry]

If we don't, I'll assume the above tips were deeply flawed, and you're still damping down after the blaze ....

BTW, are the early 912's on CDi, or conventional (for their time) ignition?

[gav p]

If we don't, I'll assume the above tips were deeply flawed, and you're still damping down after the blaze ....


BTW, are the early 912's on CDi, or conventional (for their time) ignition?

- its all completely conventional across the 5 years of '12 production. Nothing fancy

[impmad2000]

In that case I was worrying about nothing as there is no CDi box. Useful reference for 911 owners though.
You should use a low wattage bulb though, upto about 5Watt probably.
Tim

[gav p]

You should use a low wattage bulb though, upto about 5Watt probably.
Tim

I was using a 21W... not surprising things werent going well! Will be trying again tonight.

[gav p]

mmm.. Had another look at the car last night.

WHAT A MUPPET!! The reason for there being no spark was that the, er, immobiliser was on..... aghhhh!

Did the timing pretty easily once I'd worked that one out....

Cheers..