1977 280z EFI Nightmare

[Zed Head]

17 minutes ago, ckurtz2 said:

The timing light shows the pulley mark is bouncing around about 4 deg each way.

Edit - forgot that you checked the advance mechanisms already.  So this might not be a factor.  You should have a steady timing light though.

Have you had the breaker plate off of your distributor?  Might be that your advance springs are gone.  Could also explain the problems with timing if the distributor goes to full advance as soon as it starts turning.  Then the weights bounce off of the slot ends with no spring force on them.

Here's the guts of a ZX distributor, about the same as a Z's.

https://www.atlanticz.ca/zclub/techtips/distributorrebuild/index.html

Most of us end up looking at about every single part of our cars before we get them sorted right.  They're old and worn.

Edited May 19, 2021 by Zed Head

[ckurtz2]

Another update. Re fired it up, really struggled this time. Back to sounding like its cammed with chop chop chop. In addition, the volts on the dash read now about 2, but at the battery i get about 12.6. Dash used to be accurate before.  I am hoping that is a problem I can ignore for now.

I will start going through the distributor. I haven't gone through the internals yet so it should be good to go through.

Yip, I believe it. Car has to put you through hell before it starts to give anything in return. I still think I am going to do that potentiometer trick though. Can't hurt.

 

Edited May 19, 2021 by ckurtz2

[siteunseen]

Kind of like a girlfriend, no? Take you down then slowly bring you back to good. 

I won't get a haircut until she makes me.

 

[siteunseen]

1 hour ago, ckurtz2 said:

Yip, I believe it. Car has to put you through hell before it starts to give anything in return. 

 

[ckurtz2]

1 hour ago, siteunseen said:

Kind of like a girlfriend, no? Take you down then slowly bring you back to good. 

I won't get a haircut until she makes me.

 

Exactly, haha. Resist the haircut by all means🙃.

Yah this car is an evil girlfriend, she keeps digging all the money out of my wallet with a smile, then coughs and sputters it right back at me. Thank God she hasn't got ahold of a credit card🤣

Like I tell everyone who asks about my car. She has an attitude problem and nothing I do pleases her, but in time she will turn round. Or cough a piston through the hood.

[ckurtz2]

Does anyone know who makes good remanufactured distributors for these cars? I am going to go through the process of testing it, but I would like to have a backup plan if it fails

[ckurtz2]

I can get one from partsgeek or rockauto. I am just worried those will be lousy rebuilds.

What do you think of this company? http://advanceddistributors.com/wordpress1/ 

 

[grannyknot]

20 hours ago, ckurtz2 said:

I can get one from partsgeek or rockauto. I am just worried those will be lousy rebuilds.

What do you think of this company? http://advanceddistributors.com/wordpress1/ 

 

You will almost certainly get a better product from an independent distributor specialist than you will from rockauto , of course it will cost more. You could also have a go at it yourself, those dizzys are not very complicated, pretty basic to teardown, clean and reassemble.

Edited May 20, 2021 by grannyknot

[dutchzcarguy]

49 minutes ago, grannyknot said:

those dizzys are very complicated,

Am sure he meant.. NOT very complicated..   And.. take pictures before you take it apart and during it!!  you always know what it was like before..

Come on guys... let's watch this, if the single spring comes up again!!  😉 

Edited May 20, 2021 by dutchzcarguy

[grannyknot]

10 hours ago, dutchzcarguy said:

Am sure he meant.. NOT very complicated.. 

Thanks, slipped right by me.

[ckurtz2]

Ok, took a breather for most of the day, but went back at it this afternoon. I was still iffy of my timing light being correct saying 40deg advanced cause I stepped on it yesterday😬. I borrowed another to make sure. Turns out is was right, and I backed it down back to about 18deg BTDC. Now the timing light is much more stable and not bouncing everywhere, so I don't think I need that rebuild. Though I will probably get it done anyways in the future.

The chop chop chop is gone, and it hasn't spit out the intake since. The gentleman who let me borrow his timing light also let me borrow the vac gauge, because mine was broken. The results were unsettling. It seems I have like 3Hg of vacuum when idling. A good thing to note is I hooked it up at the T fitting coming off the throttle body, I just disconnected the dizzy advance and hooked it up. Not sure if this is an ok port to use. 

Now, what could cause such low vac? Could it still be a low fuel issue due to the control unit drifting in resistance. Overtightened valves maybe? I'm not sure where to go from here. I am thinking maybe of smoke testing the engine. Which speaking of that, what is a good way to go about that on these cars. I know lots of questions.

Anyways to bring everyone more face to face with the problem I have I made another video so you can see what I am seeing. 

 

 

[Zed Head]

15 minutes ago, ckurtz2 said:

A good thing to note is I hooked it up at the T fitting coming off the throttle body, I just disconnected the dizzy advance and hooked it up. Not sure if this is an ok port to use. 

Not okay.  The ports at the throttle body are "ported".  They don't get manifold vacuum until the throttle blade is opened.

A good one is the tiny one that feeds the AC bottle, or the larger one that goes over to the charcoal canister.  Both sitting right on top of the intake manifold and enter it directly.  That's where you want to measure.  Intake manifold vacuum.