valve adjust - help !

[glenncof]

I'm started valve adjust on my 1985 Cab.

I'm trying to verify TDC on cyl. 1.

I read procedures which say "located Z1 mark on pulley" and rotor pointing to "mark" on distributor case.

I can see four marks on the inner pulley. Three of them appear 120 degrees apart but two of the four are ~10 degrees apart. Also my distributor has no apparent mark for TDC. I can't see the face of the pulley (for Z1) due to damper on the Cab.

I would think at TDC the rotor should point to plug wire #1. Right ?

Help !

[Zef]

At TDC for # 1 the rotor will point on the mark you have on the distributor casting flange...You don't have the Z 1 mark indicated on your pulley...turn the crankshaft clockwise and you will see two marks separated by one inche...the left one is Z 1...! To make sure, put that mark at the bottom of the case on the joint line, and verify that the two other mark are 120 degree apart...they will line up with the pulley belt...Also, if the Cylinder # 1 is at TDC, you will have some play (.004) at the valves of that cylinder...

[SP2]

Please see my post on rennlist. I put a photo in there for you.

[rusnak]

run your finger along the outside of the dist body, and you'll feel a little ridge at the 1 or 2 o'clock position, facing the engine. You have to take the distributor cap, rotor, and little dust cap thing off first.

Then reinstall the rotor. When they say the rotor "lines up with the mark on the body" they mean APPROXIMATE. It isn't a really precise alignment. However, TDC is precisely marked on the crankshaft pulley. You trust the pulley marks, and use the dist rotor as a reference.

Memory does not serve here, but I believe TDC #1 is the second of the two marks that are close together. Look at the distributor for guidance. The other two at a 120 are for cyl# 2-5.

[2.7RACER]

glenncof,
When you are near TDC for number one, BOTH rockers for #1 will be loose. They will have been loose for over 90 degrees before TDC compression and will continue to be loose for over 90 degrees after TDC.
Since you are adjusting valves, use a light to look at the rockers against the cam lobes.
Once you get near TDC compression, both rockers will be riding on the "base circle" (the low part) of the cam lobes.
If you are near TDC crossover, which is 360 from where you want to be, the exhaust will be just closing and the intake just opening.
Engines 101.
Remember, it isn't critical to be exactly on Z1 TDC compression, because both valves have been closed and will stay closed for over 90 degrees of crank travel.
The key here, if you are new at this, is to take your time and think about what you are doing.
It ain't rocket science.

[zbph10]

This is the picture I always use, don't remember who sent it to me but it's right on.



Brian

[glenncof]

Thanks everyone. The picture of the pulley is great. I found the mark on the distributor after pulling the rotor and dust cover, it was not very clear but aligned with plug #1 wire. Actually all the plug wires were aligned when in proper position for the respective valve.

2.7RACER, probably the biggest help was your post somewhere on the 1mm per screw turn. Only small fractional turns are required.

Mine were tight. Exhaust 1,2 had no play so I could not verify where I was. I had not done valves in a LONG time, 56K miles ? (yea, shoot me...) I only got one side done, the other side will be faster now that I know what I'm doing.

Thanks for quick response.