if its correct
Timing Light Help
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
Timing Light Help
I returned my neighbors OLD timing light and bought me a Actron light(7529) It reads RPM, Advance etc. Not quite sure how to use it. Its great for RPM, thats simple. I was playing with it today. The up and down arrows apparently move the timing mark foward and back. But does it hold at that spot when disconnected ? How does this work ? Im used to moving the distributor. Any comments ?
Drifting
Joined: May 2003
Posts: 1,979
Likes: 48
From: Lakeport CA
That up down is to compensate & let you set the timing to an easy to find mark. Say 0 (zero) instead of 8 etc... You are NOT actually adjusting the timing by doing that. So, warm up the car, unplug the timing check connector, single wire connector (brown wire) sticking out of the main harness. Mine is close to the wiper motor but I've seen some closer to the power brake booster. Unplugging the wire disables the ECUs ability to adjust the timing in it's own. Set the base timing & then shut her down, reconnect & then clear the code that was set by having the connector undone.
This is all covered in the factory service manual if you don't have one yet.
This is all covered in the factory service manual if you don't have one yet.
Melting Slicks
Joined: Apr 2002
Posts: 2,118
Likes: 0
From: St. Charles, MO Route 66 Corvette Club
Trog: I have a similiar timing light and have often wondered about the little "Advance Dial" on the device. I always set the dial to "0" and do my businses. Would you mind providing a little more info on this advance dial for us technically challenged folks? Thanks!
Instructor
Joined: Jan 2006
Posts: 192
Likes: 0
From: Dayton WA
if your timing requires 5 degrees BTDC then set 'the little wheel to 5 and the timing mark on the engine at 0 degrees will actually be 5 degrees advanced....simple and sometimes easier than reading the little lines on the engine
Team Owner
Joined: Sep 2003
Posts: 88,393
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From: eville in
Drifting
Joined: Sep 2005
Posts: 1,867
Likes: 3
From: Pasadena Maryland
Yes it is correct. You can also use the light to see timing beyond the scale on the engine. Turn the dial until the timing mark is on ZERO and the scale on the timing light reads the timing. Thats how we used to read total advance, before computer controlled ignition.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 32
From: The Top of Utah
Another way of stating it is, Turning the dial (on mine) or pushing the up/down buttons, only alters (delays) the flash from the timing light. If you push up/down until the timing mark on the engine reads zero, then the number on the dial of your timing light will read the number of degrees of advance. Add the number on the dial of the timing light to the number you see on the damper, and you will get the number of degrees of advance.
RACE ON!!!
RACE ON!!!
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
OK, so tonight I pressed the up/down buttons until the timing mark got to Zero. It read 7.4, like the instructions say, I wrote it down. This is the intial timing measurement. Not quite sure what to do with this. Now to set the intial timing it says push the up/down button until the desired timing is displayed. Loosen the distrib. and rotate it until the mark is aligned with the staionary Zero. Not sure whats is happening here. The light isn't telling the computer anything, so if I move the mark to Zero and the desired timing is say 8*(indicated on the light display) will it be 8* when it's all said and done. I'm confused. 
Sorry for the ignorance here, but this is one gadget I can't figure out.
Sorry for the ignorance here, but this is one gadget I can't figure out.
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Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
The light isn't telling the computer anything, so if I move the mark to Zero and the desired timing is say 8*(indicated on the light display) will it be 8* when it's all said and done.
When setting base timing, the only reason to offset the value at the light is for convenience in reading the damper mark at the zero mark on the engine pointer instead of at one of the smaller graduations.
For me the real advantage of such a light is that you can read total timing advance once the computer has control over total ingition timing by simply dialing up the advance number on the light till the mark on the damper aligns with the zero mark on the engine pointer.
Drifting
Joined: Sep 2005
Posts: 1,867
Likes: 3
From: Pasadena Maryland
The dial/push buttons on the light do NOT effect engine/ignition timing. They only delay/retard the flash of the light to make it appear to move the timing mark. You are correct, if you want 8 degrees of initial timing and you set the light to 8 degrees, when the timing mark appears at ZERO you will have 8 degrees of timing. To check, set the light for 0 degrees and look at the timing mark, it SHOULD be at 8 degrees
Last edited by kalister1; May 1, 2007 at 02:46 PM.
Melting Slicks
Joined: Apr 2002
Posts: 2,118
Likes: 0
From: St. Charles, MO Route 66 Corvette Club
Dads90: It is amazing that something so simple can be made complicated. My first timing light did not have the adjusting feature and my current timing light has the feature......and I do not use it! Here is how I would use your timing light:
1. Set the dial or number to ZERO on the timing light.
2. Disconnect the timing connector to the distributor and loosen the distributor hold down screw.
3. Start engine and read ignition timing from the indicator adjacent to the vibration damper.
4. Adjust the distributor to 6 degrees before top dead center or whatever timing you desire.
5. Tighen the dist hold down screw and recheck timing to assure you have the desired value
6. Reconnect the timing connector
Done deal
1. Set the dial or number to ZERO on the timing light.
2. Disconnect the timing connector to the distributor and loosen the distributor hold down screw.
3. Start engine and read ignition timing from the indicator adjacent to the vibration damper.
4. Adjust the distributor to 6 degrees before top dead center or whatever timing you desire.
5. Tighen the dist hold down screw and recheck timing to assure you have the desired value
6. Reconnect the timing connector
Done deal
Last edited by Sam Lam; May 1, 2007 at 09:45 PM. Reason: edit for error!
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Originally Posted by kalister1
You are correct, if you want 8 degrees of initial timing and you set the light to 8 degrees, when the timing mark appears at ZERO you will have 8 degrees of timing. To check, set the light for 0 degrees and look at the timing mark, it SHOULD be at ZERO.
RACE ON!!!
Drifting
Joined: Sep 2005
Posts: 1,867
Likes: 3
From: Pasadena Maryland
Change the bolded "ZERO", the last word of the quote to EIGHT DEGREES. Another time. You can set the light for the desired number and turn the distributor until the timing marks read zero, or you can set the timing light to zero and turn the distributor until the timing marks on the engine read the desired number.
RACE ON!!!
RACE ON!!!
Last edited by kalister1; May 1, 2007 at 02:58 PM.
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
Well, I left the dang display on ZERO. Then turned the distributor. Thats how I've done it in the past. Good info guys. Guess I shouldn't have returned my neighbors relic and saved me a few bucks. But his keep leaving the metal plug on piece stuck to the spark plug whenever I would remove it and would have to pull it off with needle nose and fix it. 
After a few reassemblies I figured "the hell with this thing" and went out and bought a light so fancy I don't even how it works ! 
I don't give up easy though.
After a few reassemblies I figured "the hell with this thing" and went out and bought a light so fancy I don't even how it works ! I don't give up easy though.