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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

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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.

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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.

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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.

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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

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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.

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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

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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.

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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...

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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 by siteunseen

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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.

 

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I started with Zed Head process and decided to work on the idle issue first. Checked the AAR thru ECU for 12V, all good. I pulled the AAR and looked inside and there is about a 1/16" opening, I thought should be open about halfway when cold, right or wrong?

Situnseen - I do have a vacumm gauge and will perform the check. Thanks for the article on installing shaft.

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I think halfway cold is right. Put it in the freezer and see then hot water. Your cold might be 80 outside. It's  92 here. LOL

It's always warmer here so my AAR is useless. 

Sorry I haven't read the whole thread but surely you've turned the idle adjustment spring up top after the throttle body? Another thought, is your throttle body plate closing completely? I've had to clean my with lacquer thinner and a toothbrush. They get gunky.

Edited by siteunseen

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12 minutes ago, chiefmd said:

I started with Zed Head process and decided to work on the idle issue first. Checked the AAR thru ECU for 12V, all good. I pulled the AAR and looked inside and there is about a 1/16" opening, I thought should be open about halfway when cold, right or wrong?

Situnseen - I do have a vacumm gauge and will perform the check. Thanks for the article on installing shaft.

The AAR does the same thing as the idle adjustment screw.  You could just open up the idle adjustment screw to see if it starts and holds idle.  If it works then the idle speed will slowly increase the engine warms up.  It will be a good clue about the problem though.

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Well I placed it in the freezer for a few hours and then in hot water. Here are the results. When I took it out of the freezer is was about halfway open and after the hot water it was fully closed. So I guess it is functioning as it should. On to the next item.

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Zed Head- I checked my old distributor against the rebuilt one and there is about 1 1/2 dash mark difference which would be about 6 degrees according to the picture you supplied.

The new distributor is set on the second dash mark from the top (as shown in you picture) while the old one was about 3 1/2 marks. Should I go ahead a reset to were the old one was (3 1/2 marks)?

Do you think that would be the difference of 10 btdc and 15 btdc?

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The timing light tells you what your timing is.  It is what the light says it is.  Not sure that fiddling with the distributor will help things unless you want to run with 20 degrees initial timing.  That's pretty high.  You could easily end up at 40 degrees at 2500 RPM which your engine might not like.  Some of the 280Z distributors even have 11 degree weights, for a total of 22 degrees on top of initial.

I don't really know what's happening with your problem.  I'm still leaning toward vacuum leak.  The Aussie Home Built Z guy just posted a video about having to run very high advance numbers for timing then finding out that his intake manifold wasn't bolted down.  Big leakage.  I think it's in his "Dyno day" video.  Once he fixed the vacuum leak he got back to normal.

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I have been following Jeff's videos. I will go review that video again. I do know that I have the washers installed and all was torqued to specs. Today I did take a vacuum reading from intake manifold and surprise surprise 3-5 lbs and 10 when reved. Not good

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1 hour ago, chiefmd said:

Today I did take a vacuum reading from intake manifold and surprise surprise 3-5 lbs and 10 when reved. Not good

I think that lower vacuum when revving is a sign of a leak.  At higher air flow the leak gets overpowered.

Don't forget the EGR system.  It's a known problem.

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I had a problem with my EGR.  You take a handheld mirror and look under the intake manifold closest to the windshield.  The coupling hooks there, mine was loose for who knows how long and rotted out my EGR chamber? I think it's called.

This is after I replaced everything but gives you an idea of what I'm talking about.

Another thing that happened to me, and me only apparently 'cause I'ma stupid sometimes, I put the valve cover gasket on upside down and created a small opening above the thermostat housing.  They have a straight side and mine was opposite.  I know that's not your leak but it's something to look at.

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Well after going thru every EFI check and confirming everything was within specs I was getting close to giving up. I kept thinking about what Zhead said about vacuum. SO I went in that direction but couldn't find and leaks. So I removed the EGR valve and started the car with the EGR port in the manifold open. The car idle at 800. So that led me to believe I wasn't getting enough air. I removed the hose that goes from the throttle body to the AAR and then removed the nozzle on the throttle body where the hose connects. Turned it over and the gasket on the bottom, WHICH I HAD MADE,  was missing the center hole. I guess for whatever reason I forgot to punch it out. So, just want to thank everyone for their input and for making me think harder than I'm use to. Thanks again. 

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