Need help with ignition

[garretthes]

I have read and searched this out. I read 10 pages of a similar problem but still have questions.

Of all the Z sites this one seems to have the most knowledgeable and helpful people.

My daughter wanted a Z project so we found a 79 n/a with an 83 Turbo parts car. The 79 was a driver when parked 2 years ago because the windows wouldn't roll up (I fixed this already). My guess is the car died on him and he never got it running again. I found several wiring issues. It had a new starter that wasn't wired properly. I toasted the Bw wire from the switch to the coil because the ground from the battery to starter was missing and I didn't catch it. I'm thinking he toasted the old starter trying to get the car to start.

 

Anyway, I repaired the burnt wires and everything seems OK now except I get no spark. When the wires 1st burnt I replaced one that ran from the coil neg to the chassis. I can't find this on any schematic though. What the heck?

 

I get 11 volts (charging the battery tonight) at the coil + to ground and zero at neg post to ground.

 

I figured it might be the Ignition module so after reading several posts about swapping to the GM 4 wire I tried that tonight. No luck though.

I will tackle it again in the AM.

Also of note, I read where the ecu has a green LED that lites when in use. Does this apply to the 79 as well?

I do have a FSM and will look more but no luck yet. I'm hoping the ecu is good because the parts car is a turbo

 

 

Are there any threads on here that will help me? I read this thread-

http://forums.hybridz.org/index.php/topic/89168-240z-electronic-ignition-help/

Thanks guys.

Long term plan is to swap an LS engine. I did that with my 1959 Apache Suburban and love it. I drive it anywhere and get 20mpg.

Edited October 7, 2010 by garretthes

[wagon jon]

The big black wire with the white stripe is the coil positive switchable power on from the key. (There is a blue wire that is on the negative side). That black wire needs 12 volts for the coil to work. The other dilemma could be the little black box that hangs on the side of the distributor. This is the igniter box. If that is fried, your engine will not run. A trip out to the wrecking yard will solve that problem. New ones are about 300 dollars. There is a little resister that is bolted above the coil. It has a little black wire with a white stripe. The other end of it is a black wire that is grounded to the front bolt of the base of the distributor. Make sure all you grounds are clean and secure.

 

 

You mentioned "Anyway, I repaired the burnt wires and everything seems OK now except I get no spark. When the wires 1st burnt I replaced one that ran from the coil neg to the chassis. I can't find this on any schematic though. What the heck? "

 

The negative side of the coil is not grounded to the car. The blue negative wire from the coil goes to the black igniter box on the distributor.

Edited October 14, 2010 by wagon jon

[NewZed]

I think that your coil should have battery voltage (12 volts) at both + and - terminals when the key is on. The primary winding current flow (in conjunction with the capacitor/condenser) is what energizes the secondary windings. If you have voltage at the + but not at the - then I believe that your coil is not working right.

 

And that's why the - goes to the ignition module. When the current flow to the capacitor side is stopped (points closing or module triggering) the coil sparks.

 

My limited understanding of coils and ignition systems...feel free to shoot me down if I am off-base.

 

p.s. I think that in the past you have mentioned a smoking condenser. The condenser is part of the ignition circuit and needs to be working also.

 

You can test all of the components with a multimeter.

 

 

 

Edited at 2:46 - think I had something backwards.

Edited October 14, 2010 by NewZed

[garretthes]

Very strange about the coil ground wire. I'm wondering why it was there.??

I finally got it running. The problem is when the key is turned to the start position the coil loses power. We ran a temporary jumper from the battery to the coil and got it running. I'm hoping to fix that soon. Maybe the ignition switch?

[wagon jon]

Yes it could quite possibly be your ignition switch. Just this morning, I went to go to the store and my zx would not start. After some trial and error, I narrowed my search to the ignition switch. An hour and a half later, with the new ignition switch in place, the car started!

 

Check the switch!!!! No, Replace the switch!!!

[garretthes]

Update and question

I replaced the ignition switch and fixed the coil power problem. Swapped it with the 83 switch. One last problem.

I have a problem with a short to ground when I crank the car. The car cranks and runs but it blows one of my 20 amp fuses I replaced the fuse-able links with. I found that with the ignition ON the coil BW wire shorts to ground. I discovered that if I unplug the EFI relay the short goes away.

I have traced the problem to the green wires at the relay. After close inspection of the wiring diagram I noticed one of the G wires leaves the relay then goes to a connector. It appears to my untrained eyes this connector (under C3) connects the G wire to a BW wire.

Confused