mechanical timing off for timing light, split crank pulley?

[1Gina2G]

Trying to get this ignition timing set for the longest time, finnaly got to it. This is a 6 bolt block with a 2g head in a 2g chasis, using the adjustable CAS. I let the engine warm up with the acceesories turned off, and then grounded the timing connector, after hooking up the light.

What I'm noticing is, that when I have the gun set at 5 degrees, and when I move the CAS to where it shows the crank mark matching up to 5BTDC, but with the CAS in the same spot, the intake camshaft mark looks a cupple teeth off, but I checked mecahnical timing the other day and the marks were aligned still, with the tensioner in the right postion.

is this a mechanical timing problem? What else should/could I check using the adjustable timing light?

Also, not sure what it means on the write-up on without the lower timing cover, to use just the cams, what exactly is a split pulley, just broken, or a crack that interferes with the marks?

EDIT- I understand the mechanical timing is the sprockets themselves being aligned, as I'm poitive they are but I can always double check. My main question is, with my adjustable light results, does that mean I'm half a tooth off somewhere?

 

[DSM1G90]

Mechanical is having all of the marks on the sprockets at their respective place with the motor at TDC with No. 1 at compression stroke.

If you get those marks all aligned up, and the pulley mark is NOT pointing at TDC on the scale located on the lower belt cover, the rubber in between the inner and the outer section of the pulley is bad causing the outer to slip around the inner section giving you the wrong readings with the light.

You DON't want an adjustable timing light. It has to flash at the precise moment with No. 1 plug wire is firing to give accurate reading.

Might need a new Harmonic Balancer pulley if this is the case.

Good luck - DSM

 

[1Gina2G]

I thought an adjustable light was better? So just get a regular inductive?

The marks were lined up when I took the lower timing cover off, but I didnt see if the pulley itself was pointing at 5 degrees or not, assumed its good as long as the sprocket was lined up.

Is there anything I can do with the adjustbale gun I have? I forgot to also mention that when shooting at the cam gears, they line up only when I move the light to 25 degrees. But with the marks correct on the crank, the cams are off with the light.

Alright so after re-reading my timing book I'm confused. It says I should adjust the gun to what the engine wants (5 btdc) but then move the CAS so that the mark lines up with 0 on the cover. True or not? I thought you move the marks on the pulley to 5 degrees before?

 

[DSM1G90]

If all sprocket marks are aligned up, the mark on the pulley will be at TDC on the cover. No "if's, or but's" on this one.


Nah, use a regular inductive timing light-say "whooey' with that adjustable stuff (or, set the unit to it's "zero" setting with no adjustment requirements involved-make it act like a regular inductive timing light). No offense, but that adjustable stuff is for high paid shop mechanics that likes to think they know what they're doing.

You have the CAS loosened up, point the gun at the timing marks on the lower cover, roll the CAS until you see the mark on the pulley point across from the 5* BTDC on the cover (have the socket on the front nut ready to cinch down that nut when you hit the mark and always recheck the timing after both nuts are cinched down). If you can't get to the *5 mark setting with the CAS all rolled to either extreme, I'd bet that the pulley's outer section has slipped on you.

If so, do this simple test: With all sprocket marks at their respective marks, put the CAS in the middle of it's roll range, snug down both holddown nuts, fire the motor up, put the gun on "zero" or no adjustment setting and see if you can see the pulley mark close to TDC.


When you shoot your light at the INT cam sprocket mark, it will be below the horizontal due to the before top dead firing.

Good luck - DSM

 

[pauleyman]

You shouldn't shoot the light at the cam gears. It's not telling you anything. The mechanical timing of the belt is either right or it isn't. If it's right leave it alone and dont worry about the cam gears. Ordinarily you wouldn't even see them while setting ignition timing so there is no reason to look at them during this procedure. Assuming your belt is correct you may adjust the timing with the CAS using the procedures you described. If it seems way out of whack as you have described I would suggest the harmonic balancer is bad as others have suggested. A quick and dirty check is to line up the mechanical marks on the belt at it stands to reason the TDC mark on the balancer would line up also.
The adjustable timing gun isn't anything fancy. They are often referred to as dial back to zero. Rather than using a plain gun or setting an adjustable one to zero you can adjust to gun to what ignition timing you want and then when testing the light will flash on zero at the timing marks. The advantage is the zero pointer is usually large and easy to read. The 2nd advantage to an adjustable gun is if one wanted to you could properly set ignition timing advance or retard off the scale and it still know what it is.

 

[donniekak]

With an adjustable light, set to 5*, the cam marks are lined up, and the crank mark will be at 0, if mechanical timing is correct, and the cas has been adjusted properly.

 

[snowborder714]

Set the car at TDC and observe the orientation of the timing mark on the damper.

Timing mark in correct position at TDC (timing mark pointed at by my finger). Notice it in relation to the dowel pin hole in the middle of the damper.

If it's anywhere other than there (about 10 o'clock), then the inner portion of your damper has probably spun, but not yet fully separated.

For example, here's where my timing mark was on my old damper. It had spun by didn't separate. All it took was a whack or two with a hammer and it fell apart though.

You can see the small split located in this picture.

 

[DSM1G90]

..and the dowel pin still at the 3:00 position. That HD outer eally took a spin.

 

[1Gina2G]

Thanks for the replies everyone, I'm really hoping my car won't stutter in drive after setting the timing with the light. As it was last time.

I know the checking the cam gears with the light is out of context, but how is it this guy on here made a write up about setting timing with the cam gears, with the adjustable CAS I have? I understand it's if you don't have a lower cover, but shouldn't both areas line up where they're supposed to with the light? I guess it does make since for being BTDC, with my intake cam question.
http://www.dsmtuners.com/forums/art...-timing-without-using-lower-timing-cover.html

I'm sure my pulley isn't spilt, but I'll double check.

so should I set the gun to 0, ground the timing, start the car, and then move the CAS so it lines up with 5 correct? Or TDC ? being 0?

With an adjustable light, set to 5*, the cam marks are lined up, and the crank mark will be at 0, if mechanical timing is correct, and the cas has been adjusted properly.

So you're saying without the timing grounded (or grounded?), and the gun set to 5*, the cam marks should line up? And that the crank pulley should read 0? IF and only if my mechanical timing is correct? Along with the crank pulley not being spun.

 

[snowborder714]

Why spend the extra money and get an adjustable timing light? Just get a simple one that has no adjustments and set to 5° BTDC. This is the one I use - Xenon Timing Light

From reading how to use them though, it sounds like you can either set the gun to 5° and then set the timing mark at 0° or set the gun to 0° and then set the mark at 5°.

 

[1Gina2G]

Why spend the extra money and get an adjustable timing light? Just get a simple one that has no adjustments and set to 5° BTDC. This is the one I use - Xenon Timing Light

From reading how to use them though, it sounds like you can either set the gun to 5° and then set the timing mark at 0° or set the gun to 0° and then set the mark at 5°.

I thought they were more ideal for use, sounds dumb but I already bought the adjustable light I have some months ago. I'll buy a regular one if I have to, but if not I'd like to use what I have.

I'm fixing to go out in the garage now, I can make videos if needed. Is what I highlighted in bold above^^ correct?

 

[snowborder714]

I would say it is from my research on how adjustable timing lights work. I would do as follows:

1. Start car and get up to operating temp.
2. Hook up timing light and set it 0°.
3. Ground timing connector (brown plug on firewall on 2ga vehicles).
4. Loosen nuts holding down CAS just a bit so it rotates, but doesn't flop around.
5. Shoot gun at timing mark on damper and rotate CAS to align mark with 5° BTDC line on lower timing cover.
6. Tighten down nuts for CAS without moving it and recheck with timing light.

 

[1Gina2G]

I would say it is from my research on how adjustable timing lights work. I would do as follows:

1. Start car and get up to operating temp.
2. Hook up timing light and set it 0°.
3. Ground timing connector (brown plug on firewall on 2ga vehicles).
4. Loosen nuts holding down CAS just a bit so it rotates, but doesn't flop around.
5. Shoot gun at timing mark on damper and rotate CAS to align mark with 5° BTDC line on lower timing cover.
6. Tighten down nuts for CAS without moving it and recheck with timing light.

Thanks again, for all the help in my threads. Do you happen to know, when grounding the connector, does it matter if the engine is on or not. I never saw anything specific about that, but I recently saw posts about turning it off, just before grounding it.

Also, any idea of what the cam gears should look like if the crank is set at 5* on the cover? I know it may be irrelevant, but it's always good to have something else to go by. From above, it sounds like I should be seeing atleast my intake marks below the horizon because it's before, so my exhaust stays on the horizon line right?

 

[snowborder714]

I have always used link to ground it and I always do it with the engine on. Grounding the plug will make the car run differently, but I can't see why someone would say only connect/disconnect when the engine is off. I would say leave the car running when you ground it to verify the idle does change. Then when you unground it, the idle should return back to normal.

No idea on how the cam gears should look if you try and time it from there. Never tried it or saw a need to try it.

 

[DSM1G90]

My timing light is a 1983 Sears $25 dollar cheapie induction light - tuned many vehicles with that unit.

Pointing the light at the cams is just fun to look at to see where the marks are at, but not a good practice to offically use.

Let's introduce the OP to :

http://vfaq.com

and

Engine Timing

..and you can use this link as well for a basis:

http://www.vfaq.com/mods/wayback/BradBauer/engine/timing.html


good luck - DSM

 

[1Gina2G]

Yeah that's what I was thinking actually, good to know it'll sound different once grounded. Unless it's basically on it already right?

I just added the link where he uses the cams & adjustable light to set it at 5BTDC, without the lower cover in my above post.

As I mentioned above, last time it seemed the cam gears only showed alignment when the gun was adjusted to 25*. Not sure what that means, but it's why I felt my mechanical timing was off. Going to shoot the light now, see if anything changes with the cams. Really wondering about this actually.

 

[snowborder714]

Yeah that's what I was thinking actually, good to know it'll sound different once grounded. Unless it's basically on it already right?

Nope, it'll change how it runs whether it's at 5° BTDC or not when you ground the plug. Do not use the sound as a guide as to whether it's timed or not.

 

[pauleyman]

If you're wondering if your mechanical timing is off then check it. Manually check it, no light, no dials, check it by verifying the marks on the cams and crank. I think you're over analyzing this job because you've been shooting the light at your cams. Stop doing that. As above if you suspect your mechanical timing then check it. If you don't then proceed with setting ignition timing.
You do not need to sell your adjustable gun and buy a regular one. The setting is merely for convenience as explained above. You must ground the check connector either with a jumper wire or via dsmlink. You cannot set ignition timing without doing this.

 

[DSM1G90]

The ground wire disables the ECU from controlling the CAS so base timing can be made.

If you don't, setting timing is useless.

Plain and simple.