finding TDC...

[Johan123m]

Today I'm starting my first diy valve-adjustment. I think I'm well documented. Read a lot of tech articles on this site and have '101 projects' at hand.

But...I'm not sure about the TDC (z1 mark). There are 2 marks on the crankshaftpulley. I thought the first one was the 5° before TDC and the second the TDC-point (turning clockwise), but it's the other way around.
Is this normal on a 2.4T ('73)?


feedback please
Ciao
Johan

[Walter_Middie]

Early-S-Man has some great posts that will show this. Try this one:

distributor question

The notch to the left of Z1 should be 5 deg ATC. This is used for setting the initial timing with the vacuum hose connected. The vacuum at idle will retard the timing to this point. As soon as you open the throttle, the vacuum will drop, and the distributor will begin to advance.

Hope this helps.

[2.7RACER]

Johan,
No doubt by the time you read this you will have finished your valve adjustment.
This is the deal. At TDC "compression stroke" both valves will have been closed for over 100 crankshaft degrees, and will be closed for over 100 degrees.
So if you are doing number one, if you are within 25 or 50 mm of the Z1 mark either way, you will be fine.
Just get a strong light and make certain the rockers are on the heel (low side) of the cam lobe.
The only real issue about Z1 is whether you are at the compression stroke or the cross-over. At crossover, the exhaust has or is closing and the intake is or has just begun to open.