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Engine timing without timing light?

Is it possible to properly set the ignition timing with a basic actron scan tool and skip the timing light altogether? My scan tool shows engine timing so that’s why I’m wondering. Plus it seems like it could be a bit easier.

Are you referring to a distributor ignition. If so your scan tool shows timing relative to base timing and if your base timing is off 10* the scan tool’s indicated timing is off that amount…

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Yeah, it’s a distributor ignition. I had to remove the distributor to remove the camshafts so I guess there’s no way around a timing light. While we’re on the topic. My crankshaft pulley has two timing notches so I’m not sure which on to use to line up with the mark on the timing belt cover. My repair manual doesn’t make mention to these notches, it just says to use the yellow mark which doesn’t seem to make a whole lot of sense. My timing belt cover has a T and the number 10 on it. So should I just put one notch at the T and the other at the 10?

Wait a minute. I’m not sure I understand. You’re saying it can be done with a scan tool?

I used to own a 1997 Protege 1.5 with a distributor

If you want to be sure, there’s no way around using a timing light

a halfway decent timing light isn’t very expensive

Do you have a service manual . . . even a Chilton or Haynes would do . . . it should show you which marks to use

If it is a really old car with points and distributor our rule of thumb was to retard the distributor until the idle started decreasing, then give it 1/4 turn towards advance, Not recommending it but just saying that was the thing us hillblillys did. Must be a pretty fancy dancy scan tool, if it tells the timing, why not? Remember skipping the feeler guage for a dwell meter, and when I did get a timing light I recall the vacuum hose had to be disconnected and maybe even plugged for a proper timing check, so I say do it the old fashioned way, or per the manual.

It depends on the year really. That particular car from 95 on its a definite no. You have to ground pin 10 on the diagnostic port next to your fuse box under the hood so the ECU doesn’t advance timing on its own. Then you turn the distributor to set your base timing to 0 (give or take 1 degree I believe) with a timing light. Sorry but there really isn’t much of a way around using a timing light to correctly set base mechanical timing with these cars. If the timing is too retarded you loose fuel economy, if its too advanced then as the ECU adds timing you could run into knock. I can’t speak for the design tolerances of your engine so its best to just do it by the book.

I still have a decent one I’ve kept for nostalgia. Actually used it ONCE 5 years ago. Use to use it all the time. You can get a decent one for $50. Mine is over 40 years old. Not sure how long they’d last with a professional mechanic.

I have a nice Sun timing light with an advance meter on it.

Some of the chain parts stores lend tools. Well, actually you pay for the lent tool and they refund it all when you return it on time and in good condition. O’Reilly’s lent me a cooling system pressure pump/gauge. Someone may have a timing light for you.

It’d probably last a long time, because unless you’re constantly working on classics or really old pos cars, the timing light doesn’t see much use nowadays

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Funny but I have used a timing light when diagnosing a lot of difficult problems @db4690. And while most of the time it didn’t help occasionally it lead me to find some somewhat unrelated problems.


Indeed. When the fuel pump went out in my '79 Celica, i used a timing light to determine if it was a fuel pump issue or lack of spark. The flashing light ruled out the ignition system.

BTW: Did anyone notice that, in the Progressive insurance commercials that Flo’s “Name your price tool” looks like a timing light with the cords cut off? :slight_smile:

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Redneck timing light:

Shine a bright light at the timing marks

Look at the timing marks and close your eyes.

Place the #1 spark plug wire on the tip of your tongue.

Have someone start the engine, and each time you get zapped, blink. :crazy_face:



That is so bad. Please don’t try this at home.

I believe we have a Weiner…

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Make sure to have some one there to hold the beer.

Now? - Yes I agree. But 40 years ago when you could adjust timing I wonder how long one would last for a mechanic. I only used it a couple times a year (once for my vehicle and once for my wife’s). You probably owned one a lot better then the one I bought. It wasn’t the cheapest, but it was far from the expensive ones.

I remember we had to tape up the cable on our timing light at the shop back in the '70s, but other than that, it held together pretty well to daily use.

I think I burned mine out-never used it much. I bought that set at Target for about $20 40 years ago that had the timing light, compression tester, etc. Still got the dwell meter too and all are collecting dust. I did use the compression tester on the lawn mower last year but that’s it.