Jump to content
iscnetwork

1975 280z 2+2 will not start

Recommended Posts

I drove the car in the garage 2 years ago.
Yesterday with a new battery it would not start.

Turn the key and the solenoid will not kick in to turn over engine. (A screw driver works though to turn over the engine.)

There is no gas coming out of the fuel filter with key turned on.
There is no spark from coil or even voltage to coil.

I am guessing a relay, but I haven't a clue which relay is what and where is the one I need to look at.

Thanks to all in advance.

 


 

Share this post


Link to post
Share on other sites

With the key in ON the fuel pump doesn't run unless the flap is open in the AFM. When measuring voltage at the coil, where did you put the probes? If you were touching the positive and negative terminals of the coil, you should see no voltage.

With the lack of solid information, we can only just guess. The primary guess for me is the ignition switch. That is the module behind the key where the wiring harness connects.

Share this post


Link to post
Share on other sites
36 minutes ago, SteveJ said:

The primary guess for me is the ignition switch. That is the module behind the key where the wiring harness connects.

The Start wire runs directly from the switch to the starter, no relay.   So, no power at the solenoid would seem to be the switch.  There is a connection along the way though that could be loose or corroded. 

Although, I had a case where the female spade at the starter solenoid had lost electrical contact.  It was there, attached, but the metal bits weren't touching.  Crimped it tighter with a pair of pliers and was back in action.  Wiggle the yellow wire, pull it off and put it back on.

Thee should be power at the coil though, with the key on.  There are wring diagrams and service manuals in the Downloads area.

Is it an automatic?  Might be the neutral/park switch.

Share this post


Link to post
Share on other sites

I put the VOM leads, negative one to ground, then trying both terminals on the coil with the positive lead. 

4 speed in neutral.

AFM is?  sorry don't know the abbreviation. I was a body man, not a mechanic in my pass life.

I will try and get some space to get down to the starter and make sure nothing is dirty or loose.

thanks... still debugging.

 

Share this post


Link to post
Share on other sites

No voltage at the solenoid and no voltage at the coil would probably indicate the switch. That is the common point for both of those circuits with the problem existing with the key in START and ON. Also check your fusible links for corrosion. You should have two in your car. They are located on a black block that may have a white cover (or yellowed with age) near the battery. There will be either white wires or white with red stripe wires going up to the bottom of the block.

AFM = Air Flow Meter

afm_location.JPG

switch - https://www.rockauto.com/en/catalog/nissan,1975,280z,2.8l+l6,1209204,electrical-switch+&+relay,ignition+starter+switch,4700

 

  • Like 1

Share this post


Link to post
Share on other sites
37 minutes ago, SteveJ said:

Also check your fusible links for corrosion. You should have two in your car. They are located on a black block that may have a white cover (or yellowed with age) near the battery. There will be either white wires or white with red stripe wires going up to the bottom of the block.

That's a good one.  Other signs would be - does the brake light in the dash come on when the key is turned on, do the lights work, do the accessories like the radio and heater fan work.

The screwdriver on the solenoid works because that's a direct to battery connection.

Share this post


Link to post
Share on other sites
44 minutes ago, siteunseen said:

New batteries aren't always fully charged. Try an overnight 2 amp charge. Can't hurt...

With a screw driver the engine turns over just fine.

Share this post


Link to post
Share on other sites

There is a red wire going from the battery post on the starter to a relay.  That relay has the other red wire going to the solenoid.  I am laying on the fender against the wall from the front so no room to see or work on anything.

I forgot all about this it has been MSD ignitioned at some time ago. But I didn't think that would have anything to do with the coil not running or fuel pump.

What could I do just to get this thing to run and out of the garage where I have room to work on this car?

 

 

 

Edited by iscnetwork
can't type or spell at my age

Share this post


Link to post
Share on other sites

Read all of the things that have been recommended.  There a bunch you didn't even acknowledge.  Do those that you can do.  Come back with results.

You could hot wire the coil but without injector power it won't run.

It's probably a dirty fusible link connection like SteveJ said.  Common.

Share this post


Link to post
Share on other sites

I will get back to you. I will have to dig out a whole lot of car parts to even get a floor jack in there to get the right side away from the wall. 

Share this post


Link to post
Share on other sites

Fuseable links not that dirty, cleaned anyway they have continuity.  Still no good. 
Solenoid to relay wire was not that dirty, cleaned anyway.  I will attempt to pull that relay out tomorrow and make sure of its connections.

Pulling out ignition switch tomorrow after work if time allows.

Is the picture below valid for my 1975 I found in another thread?

I haven't seen it yet, where is the main ground for all stuff under they hood located? I want to make sure it is cleaned too.

(This Z has 5 times more wiring than my 240 did it seems.)

Thanks.

4973.jpg.6107ff1b1bddb66fe5c2e7abee0b4875.jpg

Share this post


Link to post
Share on other sites
With a screw driver the engine turns over just fine.

Where are you putting the screwdriver?


Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites

you are going to want to get a factory service manual pronto. will help a lot with diagnosing issues. As mentioned do your lights work (regards of ign switch they should work if the batter is hooked up), same with the horn. do you hear a relay click under the steering wheel when you turn the key to "on" Have you checked the fuse links in the battery cable? A test light is your friend when chasing electrical issues like no start.

Share this post


Link to post
Share on other sites
2 hours ago, iscnetwork said:

Fuseable links not that dirty, cleaned anyway they have continuity.  Still no good. 
Solenoid to relay wire was not that dirty, cleaned anyway.  I will attempt to pull that relay out tomorrow and make sure of its connections.

The point about the links was not continuity through the links, but connection with the terminals.  Continuity through the wires that are connected to the links.  You check that by measuring voltage, not continuity.

A 1975 280Z should not have a relay between the solenoid and the wire from the ignition switch.  Unless the car started as an automatic.  But, even if it does, the test would be to measure voltage at the relay activation wire when you turn the key to Start.

No offense, but when you have a meter you don't need to do a bunch of cleaning.  You just use the meter to tell you if the connections are good.  Cleaning without using the meter doesn't tell you anything.  You didn't use the words meter or measure once in your post.  Not good.  EFI is all about the meter.

Share this post


Link to post
Share on other sites
2 hours ago, iscnetwork said:

+ Battery terminal on starter to solenoid connection.  (bypassing the relay).

Actually that bypasses ALL of the car's wiring.  All you need for that are the battery cables.

Share this post


Link to post
Share on other sites
8 hours ago, Zed Head said:

Actually that bypasses ALL of the car's wiring.  All you need for that are the battery cables.

I was hoping with key on, it would start.  My 240z would.  I was trying to do anything to get the car out of the cramped garage so I could actually work on it.   It needed the brakes adjusted and a leaking fuel pump replaced with I parked it.

Edited by iscnetwork

Share this post


Link to post
Share on other sites

Good, I can remove the relay then.  I was planning to dig it out and see if anything else but the solenoid was going thru it to "wherever".  I have used a VOM as I go.  I test the links just to make sure they were not fried.  I had an American one once look good, dead as a door nail.

Share this post


Link to post
Share on other sites
10 hours ago, Dave WM said:

factory service manual

Best place to find?  Looking at ebay, I have a clue which one. 

Has anyone scanned one here?
 

Lights work. Horn is disconnected (previous owner put on a racing steeling wheel).

Edited by iscnetwork

Share this post


Link to post
Share on other sites
19 minutes ago, iscnetwork said:

Best place to find?  Looking at ebay, I have a clue which one. 

Has anyone scanned one here?
 

Lights work. Horn is disconnected (previous owner put on a racing steeling wheel).

The scan for the 75 is missing sections. Download the 76 as well.

Edited by SteveJ
  • Like 1

Share this post


Link to post
Share on other sites
2 hours ago, iscnetwork said:

Good, I can remove the relay then.  I was planning to dig it out and see if anything else but the solenoid was going thru it to "wherever".  I have used a VOM as I go.  I test the links just to make sure they were not fried.  I had an American one once look good, dead as a door nail.

Could you post a picture of that relay?  A PO must have installed it for a reason.  Might be that they were trying to fix the problem you're having now.

Are you sure the car did not start life as an automatic?

Share this post


Link to post
Share on other sites

I made sure the lights, turn signal, etc. work with key on/off as these all should.

For sure the relay is aftermarket "Made in China". 

It had 4 wires, 1 yellow 18 gauge, 2 red 10/12 gauge one to battery connection on starter and one to the solenoid, 1 ground.  1 Empty pin. 1 Ground.

Wiring harness that runs along the side of the engine goes to a plug (pic #1) then close to the plug the oil sensor wire comes out of the wrap, up about 6" the yellow 18 gauge wire comes out.
To save a bunch of writing is the Yellow wire that the end fell off the original solenoid wire (#2)?   It is about 18 gauge yellow colored.  IF so I can fix this part of the mess.

That ball of tape in #3 I think was a plug that was cut off for the MSD ignition.

So why I have no voltage at the coil is still a mystery.  I haven't had the time to go thru the manuals given to me above. 

 

IMG_20200924_125826105_BURST000_COVER.jpg

IMG_20200924_125850863_BURST000_COVER_TOP.jpg

IMG_20200924_125854213_BURST002.jpg

IMG_20200924_125912809.jpg

IMG_20200924_125917128_BURST001.jpg

IMG_20200924_125921756.jpg

IMG_20200924_130018983_BURST000_COVER.jpg

Share this post


Link to post
Share on other sites

28 minutes ago, iscnetwork said:

To save a bunch of writing is the Yellow wire that the end fell off the original solenoid wire (#2)?   It is about 18 gauge yellow colored.  IF so I can fix this part of the mess.

See if it gets 12 volts when you turn the key to Start.  

The early 280Z's have yellow wires that go to the brake check warning lamp and other places.  Do you see a voltage regulator?  Might be that somebody wired in an internally regulated alternator.

Looks like you're at the start of finally learning what a PO did to your wiring.  Condolences for the pain that's in front of you now.  If you have an MSD ignition it might be that your original electronic ignition module has been bypassed.  And, maybe, the PO decided to wire in a relay for the coil also.  It's looking like somebody just hacked in the wires needed to make it run.  

Share this post


Link to post
Share on other sites

No voltage on it when I attempt to crank the engine.

I don't know if the original ignition module is even there.  Don't know what it looks like.

I presume PO is a derogatory remark?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.