Jump to content

IGNORED

'75 280z can't get spark


tamo3

Recommended Posts

There is one last test you can run to be sure.  Leave everything as you have it.  But disconnect all of the wires from the negative post of the coil.  Then attach one of your jumper wires to the negative post.  Make sure that the other end of the jumper wire is not touching anything, and turn the key On.  Take the end of the jumper wire and tap it to ground.  If the coil is good you will see a spark at the spark plug on the valve cover.

 

If something is shorted out on the coil's negative post wires it can also stop the coil from working.  The circuit to ground has to be made AND broken.  If you have a short it won't get broken.

Link to comment
Share on other sites

Thanks Chas, Zed Head. I put spark plug onto the valve cover.

From Coil Negative Post, remove all cable.

Add just one green wire.

While turning key to IGN, tap the green wire other end to ground. I see spark on the cable to ground.

However, I don't see spark from Spark Plug.

Spark_final_test.jpg

 

I found one video on Youtube for MSD Blaster coil test.

 
The author said:
primary terminal test + post with - post
Set to 200 ohm scale
Expected :  0.5 to 0.7 ohm
 
Secondary test + post and main lead
Set to 2000 ohm scale
expected: 4,500 - 5,500 ohm
 
When I test with my Harbor Freight Tool's Free multi tester, the resistance shows vary for 200ohm for primary terminal test.
For Secondary test shows nothing. It shows "1" and did not change any value.
 
 
 
Link to comment
Share on other sites

I test the coil again.

I disconnected all wires from terminal. 

Set Multimeter to 200 ohm.

Connect Primary(+) to Primary(-). Result is 2.1 to 2.3 ohms.

MSD_Blaster2_Primary2Primary_test.jpg

 

I found MSD Blaster SS. I tried it...

Blaster_SS.jpg

Same result, still no spark....

What should I do next?

 

Then, Test Primary (+) or (-) to Secondary (center)

Set Multimeter to 20k ohm.

It shows both 10.43k ohms.

MSD_Blaster2_Primary2Secondary_test.jpg

Blaster_SS.jpg

Edited by tamo3
Link to comment
Share on other sites

  • 1 month later...

I replaced spark plug wire to new one. Still can't get spark.

I check 1980 280ZX FSM. P25.

1980_280ZX_FSM_EL_p25.fw.png

It says, I need to connect Voltmeter to Receptacle.

Do I need to connect to cable like this?

Photo 3-12-17, 10 34 29 PM.jpg

 

or Dizzy's IC socket?

Photo 3-12-17, 10 35 02 PM.jpg

 

When I connect cable, I got 12.Xv. But when I connect to socket on IC, I got nothing. 0.01v.

Which way is the right way to test???? 

 

Link to comment
Share on other sites

When Cranking, the positive voltage remains at the coil?  Dave had a problem with intermittent start and it turned out to be the key switch.  Just confirm that as your cranking your still seeing positive voltage to the coil.

Link to comment
Share on other sites

Tamo,

 

You should see 12 volts (Battery voltage) on "R" terminal with the brown wire. Test it with the Multimeter negative to ground.

Steps I would do:

1. Use your multimeter to measure battery voltage at the battery.

2. With ignition key on, check voltage at harness terminal "R" . Should read battery voltage. Anything less will meant you have resistance in the wire somewhere.

Like Jim mentioned, check while cranking the engine as well. The voltage will then drop because of the load on the battery from the starter, but it should be about 9 - 10 volts.

3. Disconnect the IC from the pick-up coil in the distributor. Use the multi meter on the lowest VAC setting and measure ther voltage peaks from the pick-up wires while cranking the engine. You should see peaks. Sometimes easier the read the bar graph on the multi meter display.

 

The 82 distributor has a better piuck-up coil than the 280Z model had, and should read about 0.5VAC to 0.8VAC at cranking speed.

I assume you are not getting any spark? That sounds bad, but it is easier to find problems when it doesn't do anything. A lot easier than a system that stops every now and then, like mine.

You can't test the IC with a volt meter. All you can do is eliminate all the other possibles and come to the conclusion it's the IC.

Link to comment
Share on other sites

Since you had the problem before you replaced the distributor, a problem with the ignition switch seems possible, as mentioned.  Since you removed the ballast resistor.  The R terminal at the switch.  People who have had that problem have worked around it by turning the key very slowly to the Start position.  But you should check for power to the coil during Start also, it's easier.

Don't forget to check the distributor body's ground to the engine also.  That's where the ignition module ground is.  Check for power at the coil at Start, and the ground from the distributor body.

image.png

Link to comment
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 Privacy Policy and Guidelines. 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.