Ignition help needed on '78 280z

[jrod81]

I'm having intermittent issues with starting up. I believe it is related to the ignition startup. I have read all FSM manuals. The only way I can get it to start is by using a jumper wire from the battery to ignition circuit on the fuse box in the pasenger kick panel. Does anyone know what that means?

[Zed Head]

Can you give a description of what happens when you turn the key?  What happens at On, at Start, etc.  You haven't supplied much besides the fat that you're bypassing the ignition relay.  Could be that that relay is bad.  Here's a picture of mine.  My car had a wire run all the way to the ignition switch.

[jrod81]

Thanks for the reply. Nothing happens when the acc, on, start positions. As if no power whatsoever. So by jumping the fuse box I'm bypassing the ignition relay? Where is it located?

[JSM]

Might also test the ignition switch. 

[Zed Head]

3 hours ago, jrod81 said:

Thanks for the reply. Nothing happens when the acc, on, start positions. As if no power whatsoever. So by jumping the fuse box I'm bypassing the ignition relay? Where is it located?

Is it an automatic or a manual transmission?  Automatics have an inhibitor relay.

[jrod81]

4 hours ago, Zed Head said:

Is it an automatic or a manual transmission?  Automatics have an inhibitor relay.

This is a manual transmission. Inhibitor relay I see in the electrical drawings but yet to physically find on the car.

 

6 hours ago, JSM said:

Might also test the ignition switch. 

I ruled out the ignition switch because it worked when I jumped the fuse box. Maybe that was a bad assumption. Do you know of an easy what to test the ignition switch?

[SteveJ]

To test the Ignition Switch:

With the key in the ON position, use a test light. Clip it to a good ground, such as one of the bolts on the strut tower and touch the other end of the test light to the positive terminal of the coil, where the black/white wire lands. It should light up. 

Repeat the test but have someone manipulate the switch and try to start the car while you hold the test light in place. The test light should still light up.

The good thing is that if the switch is bad, you can replace the back of it where the contacts reside. Rockauto has the part. You will probably need to remove the switch from the car to replace it. That can be a little challenging.

[Chickenman]

18 hours ago, Zed Head said:

 

 What makes you think this was " No Good " 

Edited February 26, 2018 by Chickenman

[Zed Head]

22 hours ago, jrod81 said:

I'm having intermittent issues with starting up. I believe it is related to the ignition startup. I have read all FSM manuals. The only way I can get it to start is by using a jumper wire from the battery to ignition circuit on the fuse box in the pasenger kick panel. Does anyone know what that means?

It doesn't look like you've done much testing besides turning the key and listening and looking.  And you said "intermittent" which would mean that sometimes it starts normally.  That suggests a bad connection or a stuck relay.

Best to get a meter or test light and see where the power is, and where it isn't.

[jrod81]

Thanks. I plan to start doing some testing. Will reply back with findings.

[jrod81]

On 2/26/2018 at 11:50 AM, Zed Head said:

It doesn't look like you've done much testing besides turning the key and listening and looking.  And you said "intermittent" which would mean that sometimes it starts normally.  That suggests a bad connection or a stuck relay.

Best to get a meter or test light and see where the power is, and where it isn't.

Ok folks here is where I am at:

1] Tested battery voltage  12.3V

2] With ignition switch in "ON"  tested voltage at ignition coil and got =12.3V

3] Checked power at fusible link for WR wires and got 12.3V (not indication that fusible link is good but at least there is power there)

Engine is winding over and cranking but not starting now. If i remove the BY wire from the solenoid and jump with a screw driver it still does not start and only winds and cranks.

I would presume this would work if bypassing the ignition all together and jumping from the starter - but it didn't work, if it had then I could at least narrow my troubleshooting to inside the Cabin and not in the engine electrical.

Any thoughts? Any other test to check in the Engine compartment before moving to the Cabin.

 

 

 

[JSM]

Doesn't the 78 have 4 fusible link?  Did you check them all. (not just visually but with a meter)  Also I thought there was one from the main wire from the Starter to the main harness.