Another Rookie Mistake???

[Craig Roche]

Ok, I've done it again! I removed the distributer and didn't make any marks for reference. How do I go about getting back in the right place?? Thanks again for the help!!!

[jmohn]

Turn the engine so number one cylinder is at TDC, turn the rotor in the distributor so it is pointing to the number one contact and put it in place. NOTE: the distributor tends to move slightly off when it is inserted so you may have to "anticipate" this by having the rotor slightly before (or after?) the #1 contact before attempting to insert it. Always double check this after the distributor is back in place.

Jerry M
'78 SC

[Kemo]

Oh my...its not the end of the world..Ive never done this...but it seems you could put the cap on the distributor and mark the bottom part of the distributor with a tick mark for wire #1. Then kinda get the thingy pointing at the number 1 tick mark on the lower distributor half and kinda slide it in. you may have to do a little trial and error stuff, pulling it out and moving it one tooth at a time...but thats what i would try. I dont know what the ramifications are of being off by a couple of teeth...seems like you just wouldnt have the room to set the timing the way you want... of course i would wait to see if anyone here has an opinion on that, i would hate for you to toast your engine listening to the likes of me! anyway, good luck.

[Craig Roche]

Thanks Jerry! I realize I should know this but how do I know TDC of the number one cylinder. I see the mark on the pulley and the fan housing but how do I know it's number one?? Thank you!

[klaucke]

My fan pulley says Z1 to mark when cylinder #1 is at TDC, however, you dont' know if that is exhaust or intake.

[911SCfanatic]

I think you have to pull a valve cover off also or you might be 360 degrees off.

[Hugh R]

Pull the No. 1 plug, and pump a compression tester in the plug hole to make sure your on the compression stroke, if you don't have a compression tester, you can still hear it compress, it sounds different that exhaust stroke.

[ChrisBennet]

At Z1 on the crank both #1 and #4 will be at the top of their stroke.
At TDC for #1, both valves will be closed, at the same time #4 will have one or both valves open (can't remember).
So basically you just need to determine which cylinder has both the valves closed when the crank is on Z1. A compression or leakdown tester can do this or you can pull the valve covers and make sure that the rockers on #1 have play.
-Chris

[Lukesportsman]

1. correct way with heads on is to use a dedicated tool that has a finger type stop that can be adjusted.
2. pull valve cover and watch valvetrain....too much trouble usually for whats needed.
3. remove spart plug and place finger near hole and bump over. Compression stroke will emit much more air in a 4 cycle engine. They do sell whistles for this, but I've never felt it was necessary. Remember piston will be on top twice per cylce.
4. in combination with #3, I've used a dial indicator and manually turning crank to find top true TDC.

[brcorp]

Craig,

Let me know if you need some help.

Bill

[aigel]

There is some wrong info in the beginning of this thread. It gets clarified towards the end - I hope. Here some more pointers.

The Z1 mark is the TDC mark. But you won't know if it is the exhaust or compression stroke on #1, unless you test for it.

The disstributor has a mark for cylinder #1. It is a small notch on the top of the base.

I would install the distributor with the rotor pointing at the #1 notch and the crank at Z1. If it is 180 degrees out, you will know! You won't hurt anything, unless you have CIS and no popoff valve.

George

PS: If you have a compression tester, take off the gauge section, take out the valve and screw the hose into cylinder 1. Then rotate the engine with your thumb on the hose end. You will know when you get compression. If you don't have a compression tester, just install it and hope to be correct the first time. And if you are not, re-installing it 180 deg. out, is a matter of 2 minutes!

[Craig Roche]

Thanks all for the help!! Here's what I ended up doing:

The engine is out and I wanted to adjust the valves also. There was no Z1 markings so I turned the pulley around a few times until I was sure that I was on the number one cylinder on the compression stroke.

When I put the distributor in it was pretty clear when I had the teeth lined up. One tooth back was to far and one tooth forward was to far.

Then I went about adjusting the valves with no problems. I imagine it's not nearly so easy with the engine in the car!!!

Bill, thank you for the offer to help!! Still would like to get together and check out your car.

Keywords: Distributor removal replacement install remove replace

Thanks again everyone for the help! Made it simple for me!!!!!!

[Wil Ferch]

This thread plus the embedded chart by caliber60 that I refer to....might help visualize TDC over the ange of engine operating conditions...

Stup Q of the Day - TDC???

--Wil