Ignition timing is the single, most critical adjustment for a gasoline engine. Assuming the engine is in good mechanical condition, there are no vacuum leaks, and the fuel mixture is correct, then the ignition timing can affect the net power yield from the fuel. Improper timing can significantly change a vehicle's mpg.
there are four types of timing
1. static
2 . vacuum advance
3 . machanical advance
4. valve timing
we will start with valve timing and not being familar with canadian engine we will just assume again. On the front cover of engine there might be an access hole to view cam timing mark or you may have to remove cover. the crankshaft is set on #1 cylinder top dead center and the mark on cam gear mark should allign with a mark on head. you probably should look at a manual for this. a picture is worth a thousand words. the belt can stretch and jump a gear tooth and if there are more than 50,000 miles it is a good idea to change it anyway.
next is static timing, this the one most everyone is familar with. the engine need to be warned up and running at slow idle. the distributor vacuum line is disconnected and pluged. timing light is attached to #1 spark plug wire and the light is directed in a hole in bell housing. the distributor is twisted untill the correct marks line up.
mechanical advance is checked by using same timing light procedure above . engine speed is increased to 2500 rpm and and a reading is taken. the differance between the static and this reading is your mechanical advance. also observe the timing change as you increase rpm it should advance smoothly.
last is vacuum advance. for this check I use a hand held vacuum pump. checking that the diaphram holds vacuum and also using the timing light that the timing advances smoothly and returns to static timing when vacuum is released. the vacuum advance is a common falure item.
SQUID
Last edited by squid : 04-12-2009 at 01:30 AM.
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