280ZX timing advance

[Danny_DeCheeto]

Hi all,

I'm a 17 year old doing up a 1982 280ZX, which I bought a few months ago, not running when I bought it. At the current time it idles fine, and I can rev it up. I've set the timing to 8 degrees BTDC, but I'm having trouble working out how my distributor advances the timing. I understand how mechanical advance works with weights and springs, and I've read the FSM. The FSM says that the electronic module on the side of the distributor should have 2 plugs, each with two wires (ie. four wires total). Mine only has 1 plug, the one that connects to the coil. The distributor has weights and a governor built in, but the grooves in the shaft assembly don't appear long enough to provide any mechanical advance. So it looks to me like the distributor doesn't do mechanical advance, but doesn't have the wiring for the ECU to control the timing. I've triple-checked the wiring loom, and can't even find a plug for the supposed second connector to the distributor. It looks to me like the engine is meant to have mechanical advance in the distributor.

Do I have the wrong distributor? Am I missing something?

[Linton]

old school testing..

to test your advance:.. forget the fsm... plug the vacuum line off, watching timing mark on pulley with timing light, rev engine up to about 1000 rpm watching the timing mark, it should increase with revs if it does its fine.  remove the vacuum line off the controller while holding the revs at about 1000 rpm push the vacuum line onto the vacuum controller the timing mark should raise again.

to test the vacuum controller pull the hose of the manifold which goes to the controller stick it in your gob and suck on it, if it works like a straw then the controller is stuffed. The fsm can cover various models and yours may not be the same as the book, it would not run if there was a major problem.

my controller is stuffed and blocked off, I run the timing set to static 12-15 deg at Idle and it purrs and doesn't have any engine ping

HTH

Edited October 22, 2021 by Linton

[600Z]

Hi Danny, sounds like you have the right one. the slots limit the total advance, weights and springs govern how fast eg. revs that the weights move out advancing the timing. Make sure all that is free moving etc. Do you have any pictures of it?

I had issues with 3 280ZX electronic distributors that from idle if you gave the engine a quick short rev they would retard the timing by 10 and up to 15 or more degress. With parts near impossible to get, the magnet breaks in the if looked at the wrong way i think all added to my issues.

I have since then built 2 different electronic distributors which work so much better and give a much more stable timing throughout the rev range. One having later Hitachi insides into the 280ZX distributor and the other using a Bluebird series 2 distributor with Bosch 6 cylinder insides. Both require quite a bit of work to modify but work much better then the 280ZX ones. Both are running close enough to 12 - 13 degress advance in the distributor so about the 25 degs at crank so at idle at 10 BTDC they will advance to 35 deg BTDC and so forth. Both even at 5000 - 6000 rpm the timing mark on the harmonic balancer is clear and stable with the timing light.

I have also heard of someone using the insides out of a RB30 but i haven't looked into them as the two types i have done work very well anyway.

Food for thought as there are other options in upgrading them.

 

Cheers