L24 - Poor spark... debug ?

[xray]

When (after changing the oil pump) did the problems begin? You may want to doublecheck the distributor spindle tang orientation at #1 TDC to make sure it's correct, since you have replaced the oil pump (they both run off the same gear.) I know you think it's "never [been] messed with" but it doesn't take much to mess it up dramatically.

Could you show us a pic of your rotor at #1 TDC?

Edited October 28, 2008 by xray

[biddljj]

I appreciate the advice......

Attached are three photos... All were taken with the engine at TDC on the number one cylinder.

Not just a Z - zdisease

[xray]

The rotor looks out of position if that's #1 TDC, should face more toward 7:30ish. Check your spindle tang orientation. Reasonable reference photos (post #22) can be found here

http://classiczcars.com/forums/showthread.php?t=28449&highlight=distributor+spindle

As you can see, I've been in a similar situation.

[Weasel73240Z]

The rotor is definitely not pointing where it should. Like xray said, the #1 is around 7:30 on the rotor. You seem to be pointing at the 2 or 4 cylinder where the rotor is at. I think you have a significant timing issue.

I have a diagram that Stephen B sent me when I was going through my timing issues that shows exactly where the rotor and the tab on the dizzy shaft should be at for TDC. If nobody sends it to you first, I'll post it when I get home at 4 PM.

[Weasel73240Z]

Actually I just looked at the link xray referenced, thats exactly what you need to get the timing right.

You'll need to remove the dizzy and the shaft and re-install until the tab lines up exactly like the pics in that link. When I did it, it took me about 15 tries to get the thing lined up right, but once I did, it ran perfectly.

Edited October 28, 2008 by Weasel73240Z

[biddljj]

Do I pull the tang out to reset it ?

Not just a Z - zdisease

[Weasel73240Z]

You have to remove the entire dizzy drive shaft, it'll pull right out after you remove the dizzy. It's only about 8" long with a drive gear in the middle. The drive gear engages with another gear inside the front of the engine cover. Then turn it to the left and slide it back in. Keep doing that until you have the tang aligned like in the pics. Obviously, you have to be right at TDC when you do it.

[xray]

Yes.

With the engine in the car, I've only been able to do it efficiently as a two-man job. Take off the distributor--you should see the tang, representing the top of the spindle. Use vice grips to secure the tang and keep it from falling off through the timing cover when the oil pump is removed. Take off the oil pump. Doublecheck the photos I pointed you too, to be certain the beveled edge of the tang is oriented correctly as well as the overall direction of the tang. It's easiest to move the spindle gear from below, so have a friend move it while you check its position from the distributor side against the photos (obviously, remove the vice grips prior to repositioning.)

be careful, and get it exactly right. Off one tooth, and it'll still not run well. It takes some adjustment and trial-and-error, but you'll get it right eventually!

[biddljj]

The link below is a picture of my timing marks. There are 5 timing marks.

Is the middle mark TDC ?

I am confident I am on the compression stroke due to both valves being closed.

http://www.classiczcars.com/forums/attachment.php?attachmentid=26192&d=1225162852

Not just a Z - zdisease

[Weasel73240Z]

I believe the 1st mark is TDC (if you're looking at the pulley while standing on the passenger side TDC should be the "bottom" mark of the 5) but let some other folks chime in, I'm not positive. I believe each of the notches represents 2.5 degrees, but again, not positive and I'm at work so I can't check.

[xray]

I am confident I am on the compression stroke due to both valves being closed.

http://www.classiczcars.com/forums/attachment.php?attachmentid=26192&d=1225162852

Not just a Z - zdisease

Both intake and exhuast valves are closed throughout the compression and power stroke, not simply only at TDC. TDC on compression can really be best determined by positively identifying the #1 piston at the top of its stroke when both valves are closed. The easiest way to figure this out is to place a thin wire through the #1 spark plug hole and rotate the engine by hand (rather, by socket wrench on the crankshaft bolt) When you feel the wire deflect with both #1 cam lobes pointing up/away, you're at TDC on compression.

Because of the deteriorating rubber ring in your crank pulley, those marks may or may not correspond to anything, so don't trust them. Once you've determined TDC #1 on compression, paint a small white spot on your crank pulley where your timing pointer directs. That is 0 degrees, regardless of the tick marks on your crank pulley. Static advance is 7 degrees BTDC (IIRC), so adjust your distributor accordingly.

[biddljj]

Shot.... Score !!!!!!! After 2.5 years the Z is running again.

Lesson Learned: The oil pump supports the spindle that drives the distributer.

If you swap out the oil pump the only way to maintain timing is to remove the

distributer and secure the top of the spindle with some small vice grips.

The only missing picture was one of the rotor pointing at 7:30 ish

Next hurdle is getting the seat brackets welded in. Maybe within a week....

Wish I had a mig welder... After that it's off to the muffler shop for some bending

on the exhaust.... Turns out the muffler shop owner had a ZX he loved..

I wish I could buy you guys a beer..... If you ever visit Colorado I have a cold

beer waiting for you. We live in the mountains west of Boulder.