Ok, there's three marks...which are for 18,16,14 BTC. I've seen people use digital timing lights....how do those work?

 

I don't know about the "digital" bit, but generally you just hook the light up to the battery and hook the sensor around the #1 cylinder spark plug wire and start 'er up. Then shine the light on the crank pulley and you'll see the dashes/marks.

Hope that answers your question.

-Chris

 

that's exactly how it should be done.

then you'll be able to see if it has been retarded or advanced by the degree.

 

Check your service manual before you check the timing -- you may have to jumper the service check connector, or disconnect the so-and-so first.

Also, timing should be checked at idle speed with the engine fully warmed up.

 

You should short out the SCC when checking timing. This takes out any advance the ECU might have been adding.

And of course, check timing on an engine that has been fully warmed up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by robbin &raquo;</TD></TR><TR><TD CLASS="quote"> generally you just hook the light up to the battery and hook the sensor around the #1 cylinder spark plug wire and start 'er up. Then shine the light on the crank pulley and you'll see the dashes/marks.

Hope that answers your question.

-Chris</TD></TR></TABLE>

I now have about 800 miles on my Eg/GSR Hybrid and would like to check my timing. Are there any signs that the timing may be off? I'm probaby going to pick up a cheap $50 light sometime.

These marks / dashes on the crank pulley. Can they be seen without the timing lght? I'm not understanding what the timing light does and the marks on the pulley. When I did my swap and changed the timing belt, I do recall the TDC notch but that was all. I've seen one guy using a timing light but that was all. Just saw the white light flashing as he pointed down into the motor......

Thanks to anone who can give me some info on this timing stuff

 

Ok, they can be seen without the light, and it's recommended that you highlight them with some type of metal marking pencil. Most timing lights will have 3 connections, battery positive, battery negative, and cylinder one spark plug wire. See what it does is senses the spark to cylinder one and shines the light for that instant. When you're watching the marks on the crank pulley you're seeing how many degrees before top dead center it's going to spark at. Any other questions, that's all I can think of.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Hatch &raquo;</TD></TR><TR><TD CLASS="quote">I'm not understanding what the timing light does and the marks on the pulley.</TD></TR></TABLE>

It's had to explain... but I'll give it a try.
The timing light illuminates a mark on the pulley when the spark plug fires. That notch is a certain number of degrees BTC (Before Top-dead-Center). In a distributor-based ignition system you can adjust the timing by turning the body of the distributor. This changes the spark timing in relation to BTC- each degree of change showing as the next or previous notch on the pulley.

I hope that came out clearly. Oh, well.

 

Hey guys! Taht really does make sense now how you guys explained it. I can at least the how to read the light

What would happen if the timing is off say, 2 degrees?

Thanks!

 

Maybe the "digital" bit is referring to a timing light with an advance dial built into the light...

If you set the dial to zero, or if you have a light without that feature, then you want to look for the spark timing marks. These are located at the spec. advance, like maybe 16 before on my GS-R. There's smaller marks on either side of it, which are at +/- 2 degrees from the big mark.

If you have a light with an advance dial, then you can set the desired advance on the light. But then you have to look for the TDC mark, which is the one off by itself.

Advancing the timing by 2 degrees gives you a little more power, and a little higher combustion temperature & pressure. That makes more NOx so you might fail emmissions. Advancing too far gives you preignition which could slowly burn a hole in a piston... Unless your car has a knock sensor in which case the ECM would pull the timing back if it hears knocking.

Retarding timing gives you less power, & usually lower emmisions.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JimBlake &raquo;</TD></TR><TR><TD CLASS="quote">Maybe the "digital" bit is referring to a timing light with an advance dial built into the light...

If you set the dial to zero, or if you have a light without that feature, then you want to look for the spark timing marks. These are located at the spec. advance, like maybe 16 before on my GS-R. There's smaller marks on either side of it, which are at +/- 2 degrees from the big mark.

If you have a light with an advance dial, then you can set the desired advance on the light. But then you have to look for the TDC mark, which is the one off by itself.

Advancing the timing by 2 degrees gives you a little more power, and a little higher combustion temperature & pressure. That makes more NOx so you might fail emmissions. Advancing too far gives you preignition which could slowly burn a hole in a piston... Unless your car has a knock sensor in which case the ECM would pull the timing back if it hears knocking.

Retarding timing gives you less power, & usually lower emmisions.</TD></TR></TABLE>

Thanks for that write up

So, ideal timing would be 16. Up 2 degrees for a little more power, but more wear on the motor. Back 2 degrees shouldn't even be considered.

 

It's a strobe light.
If you've ever seen something like a lathe under a strobe, you can adjust the strobe till the lathe looks like it's standng still.
I know this was already explained, but I had to throw it in.

 

And by doing that with certain strobe lights you can figure out exactly what RPM it's spinning at.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Hatch &raquo;</TD></TR><TR><TD CLASS="quote">So, ideal timing would be 16. Up 2 degrees for a little more power, but more wear on the motor. Back 2 degrees shouldn't even be considered. </TD></TR></TABLE>
They don't all have the same spec. Look it up for your year/engine. You might consider backing 2 degrees if you just failed a smog check & you have to go back to try again. Or maybe if you can't find 91 octane gas anywhere??