Looking for TDC
 

About to do my first valve adjustment on my '86 Carrera. I've looked at the tech articles and done a search, however I'm still a bit mistified about finding TDC. As I turn the the alternator nut, I see marks come up every 120 degrees on the far side (closest to the engine) of the lower alternator pully that align with the mark on the fan housing. Because the engine is still in the car, I can't see the front of the pully, where I understand when you get to TDC, there are actually two marks with the one to the left being TDC. All the pics I find show the marks when the engine is out of the car and the marks are easily identified.

Is the best way to make sure I'm at the TDC mark is to remove the distributor cap, turn the motor to each notch and when I arrive at the notch with the rotor pointing to cylinder 1, then I know I'm at TDC or are there any other secrets?

as long as you didn't take the distributor out , you can use that to find out if the mark means TDC1 or TDC4

( one crank revolution is only 1/2th of a cam revolution )

should have one for Z1 , then a one more 5 degrees to the right of Z1 (used for timing) and then couple more marks at 25 something degrees to the right of Z1 ( this depends on the model and is the advance mark)

On your 3.2 there are 4 notches on the inner flange of the double pulley. You'll be able to see them just fine. Pulling the distributor cap is a great way to keep track of what cylinder you are on.
-Chris

Thanks Stign and Chris - That is what I thought. The problem is I can only see three notches on the inner flange. They are 120 degrees apart, none of them, at least that I can see has a second mark 5 degrees to the right. That is why I'm a bit confused. I think I will take the distributor cap off, rotate the crank until the rotor points to cylinder 1, then take a close look at the flange. Maybe that second mark is there and I'm just not seeing it.

Thanks again gents!

There's nothing magical about TDC as regards a valve adjustment. You can adjust any valve at any time that it is not lifted by the cam ramps, anywhere on the back(round side of the cam will do

Once you find TDC on the pully, mark it with a touch of nail polish or some folks put a nick on top of the pully. This prevents folks from attempting to adjust the #4 cylinder on the mark a few degrees from the Z1 mark.

I use one of those White Out pens. You can put a fine line on anything with those.
-Chris

Fox - That's a great suggestion. Like Chris mentioned, I'll use some white out.

Bill Verberg's comment is one of the most intelligent responses regarding valve adjustment I've ever seen.
Look at the rockers, if the rocker is on the base radius of the cam, OK to adjust. Nice, I like it.

Not to hyjack....

But a useful hint for some...if you rotate every 240 degrees ( instead of every 120)...you can stay on the "same side" of the engine instead of jumping back and forth across the engine all the time.... when doing valves.

But be mindful of "where you are"..in the process...

- Wil