Timing Issue

[chiefmd]

1977 280Z, mild cam. I have been finishing up my winter project and everything worked out except one issue, timing. I didn't open up the engine just upgraded the fuel injection system and upgraded the alternator and the old fusible links. New clutch/pressure plate, brakes, bushes, etc so I don't believe the shaft is off. I replaced the distributor with an O'Riely remanufactured one. The only way I can get 10 btdc is (see picture) to locate it outside of the locating plate bolt hole. When I purchased the car it ran good just need some TLC. When I removed the old distributor it was located down so I know it was in the correct position.  My question is do you think if I loosening up the bottom bolt on the distributor lock down plate it would allow me to move the distributor so that I insert the upper bolt. Thanks

[Zed Head]

It might, but there's not a lot of range there if I remember right.  The slot is small.

There is also some adjustment possible on the pickup coil, maybe.  There is on the two pickup distributors, for phase adjustment between the two.

Do you still have the old one?  You might examine it and see if it has been adjusted.  Might b that the PO was one tooth off and made his own fixes.

[siteunseen]

Just a thought but how about the bolt on the other side? If you loosen it you may get the other bolt in??? I don't know for sure, sorry.

[siteunseen]

I realize now that's what you're talking about.

[siteunseen]

I loosened mine and played around with it, the spare in the picture and it worked. Give it a try. Mine is almost maxed out to as you can see in the picture. Good luck.

[chiefmd]

Well I was able to get the movement I needed to lock down the dizzy and it is set at 10 degrees but that is it. Zedhead I'll look into your suggestion. Thanks all.

[chiefmd]

Today I had some time so I went out and started the Z up. Started right up (10btdc) but won't stay running I have to keep it above 1000rpm. So I decided to, again, adjust the timing to see were it would run the best. So I removed the lock down bolt so I could advance it and it ran better at 15btdc- 20btdc. I started thinking that maybe the shaft is off one tooth. I set the distributor to #1 compression TDC and pulled the distributor. The shaft is at 11:35 not the 11:25 as stated in the FSM (see pictures. On one picture (this is at 15btdc) you can see that I can't install the bolt in the retaining hole. Also, I placed a black line on the distributor rim for where #1 wire is on the cap in relation the the rotor. Do you think that moving the shaft one tooth over would get me back to where I would be able to run at 15btdc.

  Also, I read (somewhere) when removing the oil pump to reclock the shaft that I could use vise grips to hold the shaft in the 11:25 position while reinstalling the pump, yes or no. Thanks

[Zed Head]

Your ignition timing, as shown by the flashing light and the timing mark on the damper pulley, and your drive gear and rotor are really two separate things.  And the fact that it won't stay running at low RPM is probably not a timing issue.  No offense, but you're getting things blended together.  What you're doing probably won't fix your problem, unless the mark on your damper is incorrect and what you see by the timing light is wrong.

[chiefmd]

Zed Head - Thanks for the input.  What I see with the timing light is correct and the mark on the damper is correct. Maybe I wasn't clear in my explanation but when the distributor is set at 10btdc it starts with no problem

 

1. Set at 10btdc it starts right up but won't maintain idle

2. Set at 20btdc it starts right up and maintains idle.

3. But at 20btdc I can no longer lock down the distributor as seen in the above picture.

After removing the dizzy and looking at the shaft position (11:35) and what is stated in the FSM (11:25) I thought that by bringing the shaft back to 11:25 that it would allow me to lock down the dizzy and still be able to adjust it to 20btdc.

First, does the 11:35 shaft position seem correct? Secondly, anyone have any ideas as to why I need 20btdc to keep it idling? Thank you

[Zed Head]

I would put the idle problems firstly.  A big vacuum leak might have that effect.  When you say it won't idle correctly do you mean when cold or at any temperature?  What happens if you just open up the idle speed screw on the throttle body to increase idle speed?  Does the AAR work correctly?

Anyway, there are pictures out there of rotor position but I can't find them.  The other way is to check the drive spindle tang.

[siteunseen]

I agree with Zed. Turning the dizzy clockwise increases engine idle so yeah your idle is off somehow. 20btdc is too high. The spindle could be tooth or 2 off. There's ways to cheat that by moving the plug wires on the cap. I've only read about it so no help on that you'll have to research that. Dropping the oil pump and moving it is pain but if you want it right...

All the caps I've seen have a vertical raised line on the outside that shows were the rotor button should be pointing at TDC.

Edited May 23, 2019 by siteunseen

[siteunseen]

You can get a loaner vacuum gauge from chain auto parts stores and see if you may have a leak. IIRC mine are at 17 hg at 10btdc. Just a thought. Good luck.

PS the trick to installing the spindle and pump as explained in Tom monroe's rebuild book is push it up in to the right of the top right bolt hole, engage the gears then turn the pump back to the left, insert bolts.