How do I use a timing light...

[Zack1978]

Hi everyone,
A friend gave me a new (new in box Craftsman, but the item is at least 25 years old or so...) inductive timing light. I have never set the timing on any vehicle ever before, so I have no clue how to use this thing.
I was playing around with it on my 79 Toyota 4x4 plow truck. The light has a pos and neg battery connection, and a spark plug wire clip. I used it on the truck, and I hooked the spark plug wire clip to cyl #1. I see the timing mark on the crank pulley with the light on it, and that line matches up with a line on a tab mounted to the engine. I assume that the timing on the plow truck is dead on accurate as the truck on has 37,000 miles on it and it is totally stock. What exactly am I looking for?
I also used it on my 95 Nissan Pathfinder, and I also hooked the spark plug attacment to plug number 1. On the Path I can see the pointy tab on the engine, but I don't see anything on the crank pulley. What am I missing on the Path?

Sorry for the questions, I just have no clue how to use this thing...

Thanks,

Zack

 

[Zack1978]

Also people often mention setting the timing X # of degrees above or below top dead center. How the heck do you tell where you are at when you just have this timing light thing?

 

[Ebag333]

These are the instructions I sent a friend for the 1FZ. It's somewhat different, but the basic are the same. In this case, I was advancing my timing from the stock setting.

1) Buy a timing light. I would *NOT* get a light with an advance on it, that is adjustable, or anything fancy. From what I've read, half the people with lights with advances on them hate the advance because if it's misadjusted it throws everything off. You don't need an advance on the light for the Cruiser. Also, get one with inductive pickups. It'll look like this Harbor Freight one: Xenon Timing Light

2) The inductive pickup clips around/onto the #1 spark plug wire. If you have OEM wires, it's labeled #1. It *SHOULD* be the one closest to you if properly routed.

3) Battery leads for the timing gun go on the battery....

4) Start the engine. Turn off all draws (AC, fan, radio, lights, etc). Make sure engine is up to normal operating temperature/mode. Verify you're idling around 650 RPM (I was at 625).

5) Aim the timing gun at the crank pulley. Watch the belts and fan. On the top of the crank pulley you should have a plate that's labeled 15 10 3 0. That's the timing the engine is set to. Pull the trigger on the timing gun and it'll start flashing. There's a notch on the crank pulley that will show up. At this point it should be just a bit to the left of the 3, probably around 6* or so. This is NOT your base timing, but the current timing of the engine.

6) Attached to the firewall on the passenger side is a diagnostics box. Pop it open. On the inside of the cap is a guide telling you which holes are which. Use a piece of wire or paper clip to jump TE1 and E1.

7) Go back to the front of the engine and use the timing gun again. If properly adjusted to the OEM spec, the timing should now drop to 3*.

8) There is a bolt just behind the distributor that locks it in place, loosen this bolt (do not remove it).

9) With the timing gun aimed at the crank pulley, play with the dizzy and watch the timing drop from below 0* to above 10*. Try and find the highest timing where it doesn't stutter/stumble, ping, etc. Mine was about 6* using regular fuel (not premium). It does not take much movement to change the timing. Once you've found a good spot, tighten the bolt to lock the dizzy in place. After locking the bolt, double check the timing to make sure you didn't change it when tightening the bolt.

10) Remove the jumper, and check the timing. It'll be much higher than base, mine was sitting at about 8* after adjusting to about 6* base.

11) Drive around and listen carefully for pinging, knocking, etc.

In case that's not enough, I've attached the TIS doc on it.

It's seriously a 5 minute job if you're moving real slow. *SUPER* easy, wish I'd done it years ago.

Depending on the engine, how you see the mark is different. IIRC on the 3FE there's a hole/window you look through to see it. You may need to get the FSM for your vehicle or search some forums to see how it's specifically done for your vehicle.

 

[2mbb]

The only thing I would add to the above post is:

1. before you start make sure you know what your timing mark looks like. On the 2F engine it looks like a "bb" pressed into the fly wheel. This timing mark represents 7 degrees before top dead center. (next to the BB is a scribed line. This is TDC. You use this for valve adjustments, etc., but not for setting your timing). You might think about marking it with a dab of white paint or bright nail polish or something. To find it (and clean it off) the first time, I find it's easiest to crawl under the truck and remove the clutch inspection cover. This gives you a much larger view of the front of the fly wheel where the timing mark will be.

2. The timing mark for the 2F is on the front of the flywheel, not on the crank pulley. There is a sliding window on the front of the bell housing on the right side of the engine. Open the window and you will see the pointer. The object is to line the timing mark up with the pointer.

3. Your engine should be warm and the idle speed should be adjusted properly to spec. Because the distributor has a centrifugal advance if the engine is running too fast, the timing will be off.

4. before you check and adjust your timing you need to remove both vacuum lines from the distributor vacuum advance diaphragms and to plug them. Make sure you keep track which is which so you can put them back onto the correct diaphragm. The inside diaphragm is the main vacuum advance. The outside is for the high altitude compensation. You want to plug the lines when you remove them so you don't have a vacuum leak.

 

[rove_mcanus]

The only thing I would add to the above post is:

1. before you start make sure you know what your timing mark looks like. On the 2F engine it looks like a "bb" pressed into the fly wheel. This timing mark represents 7 degrees before top dead center. (next to the BB is a scribed line. This is TDC. You use this for valve adjustments, etc., but not for setting your timing). You might think about marking it with a dab of white paint or bright nail polish or something. To find it (and clean it off) the first time, I find it's easiest to crawl under the truck and remove the clutch inspection cover. This gives you a much larger view of the front of the fly wheel where the timing mark will be.

2. The timing mark for the 2F is on the front of the flywheel, not on the crank pulley. There is a sliding window on the front of the bell housing on the right side of the engine. Open the window and you will see the pointer. The object is to line the timing mark up with the pointer.

3. Your engine should be warm and the idle speed should be adjusted properly to spec. Because the distributor has a centrifugal advance if the engine is running too fast, the timing will be off.

4. before you check and adjust your timing you need to remove both vacuum lines from the distributor vacuum advance diaphragms and to plug them. Make sure you keep track which is which so you can put them back onto the correct diaphragm. The inside diaphragm is the main vacuum advance. The outside is for the high altitude compensation. You want to plug the lines when you remove them so you don't have a vacuum leak.

A quick off topic question but if the timing mark is on the flywheel on the 2f, is the flywheel keyed so it can only go on the crank one way? All flywheels i've seen could be put on in any orientation

 

[96r50]

These are the instructions I sent a friend for the 1FZ. It's somewhat different, but the basic are the same. In this case, I was advancing my timing from the stock setting.



In case that's not enough, I've attached the TIS doc on it.

It's seriously a 5 minute job if you're moving real slow. *SUPER* easy, wish I'd done it years ago.

Depending on the engine, how you see the mark is different. IIRC on the 3FE there's a hole/window you look through to see it. You may need to get the FSM for your vehicle or search some forums to see how it's specifically done for your vehicle.

Something I've always wondered is whether you can use a Scangauge to set the timing? It has an IGN readout (mine usually sits at 4 at idle). Any idea if that would work?

 

[Ebag333]

Something I've always wondered is whether you can use a Scangauge to set the timing? It has an IGN readout (mine usually sits at 4 at idle). Any idea if that would work?

I've wondered the same. I'm not sure it'll ever read true base timing, but it would be extremely easy to jumper TEC1 and EC1, and see what the timing changes to. If it reads 3* (and you're at the factory setting) then would be possible. I'd play around with the timing and see if the scan gauge actually follows the timing when you advance/retard it.

Why don't you spend a few minutes and go find out for us?

 

[96r50]

I've wondered the same. I'm not sure it'll ever read true base timing, but it would be extremely easy to jumper TEC1 and EC1, and see what the timing changes to. If it reads 3* (and you're at the factory setting) then would be possible. I'd play around with the timing and see if the scan gauge actually follows the timing when you advance/retard it.

Why don't you spend a few minutes and go find out for us?

I may just have to do that! I have to stop by the dealer tonight to pick a few things up so I'll ask a friend there whether or not it's possible to read and adjust the distributor timing from the OBDII port. If I have some time tonight I'll try playing around with it too, although I have no timing light to compare with.

 

[Ebag333]

A basic timing light is extremely cheap. Well worth skipping a morning coffee from Starbucks (or two) to have it.

 

[96r50]

An already paid for Scangauge is even cheaper , and the last three times I went to Starbucks I didn't get what I ordered (Tim Horton's is better anyway!)

 

[96r50]

Just came back inside from checking this out. The truck usually idles very close to 650 with the ignition timing reading 4*. I popped the SST/wire into the terminals in the diagnostic port and the timing dropped to 3*. Removed the wire and it came back up to 4*. I didn't adjust anything, but it was cool to find out that the Scangauge could be used to set the base ignition timing.

 

[Ebag333]

Sounds like it! I wonder though, since it goes through the ECU if it will accurately measure the base timing if you started adjusting it. I'd imagine it would.

Amazing that you were only at 4* without being jumped. That's awfully low.

 

[Ebag333]

Just came back inside from checking this out. The truck usually idles very close to 650 with the ignition timing reading 4*. I popped the SST/wire into the terminals in the diagnostic port and the timing dropped to 3*. Removed the wire and it came back up to 4*. I didn't adjust anything, but it was cool to find out that the Scangauge could be used to set the base ignition timing.

So I tested this against my Ultra Gauge, and found the same thing.

Only problem? The timing didn't change when I adjusted the dizzy.

My guess it that the base timing is just that, base timing. What the ECU sees is assumed to be off the default 3* when jumpered and 4* when not. So if you advance your timing, you'll be off by whatever you advanced it to. (Not that it really matters, the engine timing jumps around too fast to track in real time when driving.)

 

[laguna80]

A quick off topic question but if the timing mark is on the flywheel on the 2f, is the flywheel keyed so it can only go on the crank one way? All flywheels i've seen could be put on in any orientation

I'm not sure if it's keyed, mainly because I don't know what that means. I think that if it's on the wrong way, it will be pretty obvious because the starter won't reach and you won't be able to put the clutch on either. I wondered about that too when I was repairing the rear main seal and pilot bearing.

 

[Kent]

I thought there is a small dowel or pin on the flywheel that insures it can only go on in the correct position. It's been a while since I had mine off so I could be wrong...

 

[droopy troopy]

what a gold mine of info my troopy is running like a bag of s*** right now and i'm eliminating probs, if i took of the dist. cap is there a vac. line inside i need to put back on before i clip it down? cheers