Can you time a engine to TDC using the Camshaft sprocket mark?

[TorqueEffect]

As I was trying to time my engine I couldn't see the mark on the harmonic balancer, so I thought I knew what I was doing, and I turned the engine over to tdc, and with a white out pen, marked the pulley right where the T is on the lower timing cover. I thought this was correct, but after grounding the STI then aiming a timing light at it, nothing, I then found the mark way off the scale at about the 10 o'clock position, I guess that isn't how you mark it. I don't think it is off a tooth, because the engine runs fine, except for what seems to a random miss during idle, it usually gets around 35 MPG.

But I found I could aim the timing light at the TDC mark on the camshaft sprocket, so I just turned the dizzy until that mark was at TDC. Can you time the engine to TDC or what I believe is 0 degrees before TDC using this mark? Because I believe I just did.

[dalebwilson]

It is confusing but I will give it a shot. See diagram below. There are 2 marks on the crankshaft pulley. While facing the crankshaft pulley the left mark is an indicator of #1 at TDC position while the car is not running. The right mark is for ignition timing with ST1 grounded while the car is running and using the timing light.

There are also 2 sets of timing indicators on the lower plastic timing cover. A single indicator that aligns with the left mark on crank pulley noted above. A second set of marks are actually a scale that you used with your timing light. There are 2 important marks on that scale, a "10" and a "T". With ST1 grounded and at 700RPM, you should see the #1 plug firing as the right crankshaft mark above aligns with the "10". That means your ignition system is set to spec at -10BTDC. Hope that's helpful.

Timing Marks.JPG

[TorqueEffect]

I guess my new question is where do I put new marks. Because right now the engine is timed at 0 degrees btdc, which I have researched gives good gas mileage in standard 87 octane.

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[dalebwilson]

Specification from the manual states that your engine should be firing at 9-11 BTDC. Just make sure that the crankshaft mark (on right) aligns with the "10" while running. This should put you right on. Always ensure your engine is at normal operating temp before doing this.

[TorqueEffect]

Well how do I make new marks? Obviously setting the engine to tdc and marking the pulley at the T on the scale wasn't right because then the mark showed up nowhere near the scale.

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[dalebwilson]

Remove your crankshaft pulley by removing the 4 screws and get it out in the sunlight. You will see 2 small indentions on the outer edge. Those are your marks. Mark the one on the right with white out. Make sure that mark lines up with the "10" during ignition timing.

[zoom zoom]

Youll blow a head gasket the first time you get on it or rev over 4k if you set it to 0*(tdc)

I did it once. The crank sprocket comes around twice for each rotation of the cam sprocket.

[TorqueEffect]

Youll blow a head gasket the first time you get on it or rev over 4k if you set it to 0*(tdc)

I did it once. The crank sprocket comes around twice for each rotation of the cam sprocket.

Dang, I didn't think timing could blow a head gasket. I guess I will have to take the pulley off and look for the indentations, because I can't see them at all while it's on the car, the pulley is keyed correct? So there is no possible way for the pulley to be put on without the marks facing the correct way?

[dalebwilson]

Yes the pulley is keyed and will only go on one way. You do not have to remove the crankshaft bolt. The pulley is held on by 4 10MM bolts and 2 Phillips screws. Pay special attention to the spacer washers and how they come off...there are 3 if I recall. To access the pulley, it will be easier if you remove the lower plastic cover and the passenger side motor mount. Put a jack and block of wood under the oil pan and slowly lower the engine.

[TorqueEffect]

Well after reading the haynes manual while sitting on the john, I found I used the wrong mark on the camshaft sprocket anyway for TDC. The long mark I used is NOT tdc, the smaller mark 90 degrees to the left of it is tdc. DOH!!! That might explain why the mark I made was completely off the scale.

[zoom zoom]

Yea theres 2 marks on the cam sprocket, 12&3 oclock is where they should line up.

What year is your car? Large nose pulleys are different than small nose. I know its hard but you might try hitting the outter rim of the crankshaft with a wire brush, the marks are really tiny and the paint comes off them after a few miles, use your fingernail to find them. If you feel two bumps about 1/2-3/4" apart you found them.

Dont use the camshaft sprocket to roll the engine over, but if you remove the spark plugs you can use a 1/4"x6" long extension to find top dead center. Removing the plugs also releases the compression so the engine will roll over alot easier.

Once you find tdc in spark plug hole #1 and the camshaft marks are at 12&3 you'll know that the crankshaft pulley marks should be lined up with the timing marks, so hit it with a wire brush and find those marks!

I dont know if you can see it from underneath but im pretty sure(iirc) the crankshaft pulley keyway is at 12 oclock when its at tdc.

[TorqueEffect]

Yea theres 2 marks on the cam sprocket, 12&3 oclock is where they should line up.

What year is your car? Large nose pulleys are different than small nose. I know its hard but you might try hitting the outter rim of the crankshaft with a wire brush, the marks are really tiny and the paint comes off them after a few miles, use your fingernail to find them. If you feel two bumps about 1/2-3/4" apart you found them.

Dont use the camshaft sprocket to roll the engine over, but if you remove the spark plugs you can use a 1/4"x6" long extension to find top dead center. Removing the plugs also releases the compression so the engine will roll over alot easier.

Once you find tdc in spark plug hole #1 and the camshaft marks are at 12&3 you'll know that the crankshaft pulley marks should be lined up with the timing marks, so hit it with a wire brush and find those marks!

I dont know if you can see it from underneath but im pretty sure(iirc) the crankshaft pulley keyway is at 12 oclock when its at tdc.

Well today I had the right amount of light and I found the indentations, and marked them, so I didn't have to remove the pulley. Got it timed right this time.

Going to go take a test drive now, hopefully it feels like it has more power than what I had it timed to yesterday. Yesterday there was like no low end torque until 2.5k-3k RPMs.

[TorqueEffect]

:thumbs_up: Running good, still down a bit on power, but there must be a vacuum leak I havn't found somewhere since the idle still a tad rough, and the 13" wheels probably are not helping. Becuase I know with the 12"s it has good pickup even before I re-timed the engine.