ignition timing

[iggy]

hi all my car just doesnt have any go in it, its a 2500 with electronic ignition, all though all the spark plugs are just the right colour and the previous owner told me the su carbs had been rebuilt with new needles, so to day i dug out my old strobe light to try and time the ignition no luck though, i presume looking from the front of the car the 8 degree mark before  tdc is two marks to the left or two marks anti clockwise am i right on this point? when i first put the strobe light at 800 rpm the tdc mark was well off the scale anti clock wise, i tried setting it at a few  different marks but it made no difference, all i did find was the vacuum advance works ok, any ideas am i doing some thing completely wrong?

[dazzer]

Hi iggy

You are looking for the marks btdc, before top dead centre. So if you clean the marks up on the pulley you will find a 0 which will have either side of it as you say lines marking degrees. The engine turns clockwise (looking from the front) so as you move the front pulley round the first marks that will line up with the pointer are those before top dead centre. I haven't got a manual with me but 8 degrees btdc sounds very safe you could probably advance it a little more, but stick with 8 and see how it goes.

Another thought is that you have an adjustable timing light. If its got an adjustment on it just mark TDC with some tippex or similar and then adjust your timing light control to show 8 degrees. All you need to do then is get TDC lined up.

Hope this helps.

Cheers
Dazzer

[iggy]

thanks dazzer i was right then with the timeing marks didnt no you could buy a timing light that shows degrees on it  :)

[willows40]

but wouldn`t the timing be different now as it has electronic ignition and using unleaded which is why i never use a timing light

cheers andy

[iggy]

yep i reckon your right willows40 how do i time it now

[Davemate]

I would used the timing light and set it to a known setting(8 before TDC)
Then I would go for a drive and if it "pinks" I would move the dizzy until it stops.

[iggy]

ok dave thanks

[piman]

Hello Iggy,

did you check the timing with the vacuum advance tube connected, as this may give a false reading?

Alec

[iggy]

good point Alec but i disconnected the vacuum tube but i didnt plug the connection on the inlet manifold should i have?

[piman]

Hello Iggy,

I've seen people advise that but all it does is very slightly weaken the mixture and it is irrelevant to the timing so i don't bother. Another general point about timing using a strobe is that some distributors start to advance at relatively low speed (4 to 500 rpm) so it's worth checking the distributor specification as you may need to deduct a degree or two to get true static timing as per the manual. Generally academic unless you have a high idle speed. As said the best check is to drive it and tune for advance just short of pinking.

Alec

[iggy]

thanks again alec is there a special  gallery area on the forum where members put up photoes of there cars i cant seem to find one