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tamo3

'75 280z can't get spark

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I know there are a lot of "Can't get spark" topic before here and there.

I read through those topics but still can' figure out what was wrong with my case.

It was running strong before I shut off engine.

 

Next day, I cannot start engine.

Trouble shooting what I have done follow 280zfuelinjectionbook.pdf
Fuel pump
  1. Remove Starter motor IGN line.
  2. Turn key on to the IGN position to hear fuel pump sound. It works.
 
Spark check
  1. Remove Spark Plug and leave it on the top of valve cover with cable connect
  2. Trun key onto the IGN position.
  3. No spark!
 
IGN signal blue line check
  1. Under the dashboard, Check blue line is connected.
Screen Shot 2017-10-02 at 12.48.48 PM.png
 
 
Coil Check
  1. Use voltmeter set to 20
  2. Connect Voltmeter Positive to Coil Positive and Voltmeter Negative to Battery Negative post. Result show 12V. Passed
  3. Connect Voltmeter Positive to Battery Positive post and Voltmeter Negative to Coil Negative. Result show 12V. Passed.
  4. Connect Voltmeter Positive to Coil Positive and Voltmeter Negative to Coil Negative. Turn key onto IGN position. Result 0V. FAILED

What should I test next?

Edited by tamo3

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57 minutes ago, tamo3 said:
  1. Connect Voltmeter Positive to Coil Positive and Voltmeter Negative to Coil Negative. Turn key onto IGN position. Result 0V. FAILED

What should I test next?

This part would be normal.. The + and the - have the same voltage if no current is flowing.

The two things most likely to be the source of the problem are the ignition module and the pickup coils in the distributor.  The pickup coils are pretty easy, check resistance, and air gap.  The ignition module is a little bit harder.

Might also be that something broke inside the distributor.  When you check air gap, you'll see if that's the case.

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Tamo, You have the Californian model right?

The FED system has a cold start system to retard and advance the timing by changing pickups in the distributor. You can see then with the distributor cap off, or the three wires (green, brown & red), and the 7 wire TIU. The pickups are not 180 degrees apart, but I can not remember exactly how many degrees they are.

No real way to test the module with a multi meter, except check it is getting voltage. Basically go through a process of elimination until it's the only thing left.

If you look in the last section of the instruction there is some trouble shooting steps you can take. It's written for the HEI swap, but the original should work the same.

 

TIU280Z1976_REV1.pdf

Instruction - Fitting a 4-pin HEI module to 280Z 1977 RevD.pdf

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Thanks Zed Head, Chas for your input.

My 280z is none CA model. 

Actually, after this problem, I thought ignition module or dizzy itself failure.

So, i decided to swap to 280zx distributor.

I follows blues instruction. http://atlanticz.ca/zclub/techtips/distributor/index.html

Photo 1-10-17, 2 06 41 PM.jpg

Photo 1-10-17, 4 30 13 PM.jpg

Photo 1-10-17, 11 00 42 PM.jpg

I need to modify one line. BL line needs to added to positive post on Coil. Otherwise, nothing happen when I turn key onto IGN position.

280zx_distrubutor.jpg

 

 

Now I can get rid of those...

Photo 1-10-17, 11 02 42 PM.jpg

 

Even though after swapping Dizzy, and get rid of ignition module, the symptom hasn't been changed.

 

 

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1 hour ago, tamo3 said:

, the symptom hasn't been changed.

No start, or no spark and no start?  With the new distributor you should certainly get spark.  Unless it's not turning.  People have had the distributor drive shaft gear slip.  You might remove the distributor cap and make sure that the rotor is spinning.  (Also make sure that you installed a rotor on the new distributor.  People have forgotten.).

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I can't watch the videos atm because they chew up my data on a pre-paid sim while Im in Australia. My work phone has unlimited data, but Im too far away from that providers mask.

Are you grounding the spark plug correctly when doing the test?

When I read your post about checking voltage. You say 12V. Is that exactly the same as battery voltage? A small voltage drop can mean a lot if you have no current draw.

Can you check the coil by attaching a wire to the negative post and and quickly tapping the wire to ground while the ignition is on. You will need to connect a spark plug to the HT lead coming from the coil to the dissy cap.

If you don't get any kind of spark, you have a faulty coil or the power supply going to it.

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2 hours ago, EuroDat said:

Are you grounding the spark plug correctly when doing the test?

EuroChas might have uncovered one problem with test method.  The electrode is not grounded in the spark test video.  Any part of the metal body of the plug needs to be touching a ground point.  The valve cover usually woks well.

If you re-run the test and find that you have spark that will narrow things down.  You could also put everything back together and try starting fluid.  If it starts for a few seconds then you'll know you have a fuel issue.

image.png

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Thanks Chas, Zed Head. I put spark plug onto the valve cover to test it again.

The result was same

 

 

Coil test: Positive Post

  1. Connect Voltmeter Positive to Coil Positive and Voltmeter Negative to Battery Negative post. Default shows 0v. When turn IGN, it show 12V. 

Coil_positive-Test.jpg

 

Coil test: Negative Post

Connect Voltmeter Negative to Coil Negative and Voltmeter Positive to Battery Positive post. Default shows 12v. When turn IGN, it dropped to 0.31v. 

 

Coil_negative-Test.jpg

 

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I would use the center wire from the coil, as Chas mentioned, not a spark plug wire.  You can stick a bolt in it or maybe a spark plug.  Then you'll get six times as many sparks, if the coil and ignition module are okay. 

If you still don't get any spark, connect a small wire to the coil's negative post (Chas's suggestion again), turn the key on, and tap the other end of the wire to ground.  Have the center wire of the coil, with something metallic in it, close to ground, about a spark plug gap away.  You should see a small spark there and a big spark from the end of the center wire of the coil.  You will be essentially acting as the ignition module, making and breaking the coil power circuit.  This test will narrow it all down to the coil.  As Chas said, if you don't get a spark with this test your coil is bad.

When you did the test below, what you did was connect the two leads to essentially the same point.  The coil negative is connected to the battery positive post, through the coil, then the positive post and the wiring.  Every thing looks about right on your measurements.  Do the test with the wire on the negative post.  Connect the wire, let it hang in space, turn on the key, tap-spark-tap-spark-tap...is what should happen.  Your injectors should click on every third tap also.  It's a simple test of the ECU and wiring, in addition to the coil

2 hours ago, tamo3 said:

Coil test: Negative Post

Connect Voltmeter Negative to Coil Negative and Voltmeter Positive to Battery Positive post. Default shows 12v. When turn IGN, it dropped to 0.31v. 

 

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Looks like it's coil failure.

This MSD Blaster 2 is not so old... ;-(. I will order new one.

 

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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.

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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.
 
 
 

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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

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The one thing that you haven't tested is the center wire itself.  Make sure it's good, low resistance continuity, and the terminals are firmly connected.

Your coil resistance values look about right.

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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???? 

 

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I might have missed it but you sure your getting positive voltage to the coil? Disconnect the positive wire from coil, run a temp new wire from the battery directly to the positive side of the coil. Just to ensure it's not in the wire going to the coil.


Sent from my iPhone using Classic Zcar Club mobile

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Hi JSM, yes. I’m getting positive voltage to the coil. It seems like some thing wrong to between coil to dizzy or IC. I’m trying to narrow down to find the issue...


Sent from my iPhone using Classic Zcar Club mobile

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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.

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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.

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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

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I re-checked wire again last night.... then I found out that I connected the positive wire and the negative wire opposite way to the IC matchbox.

After re-connect, turn the key..., worked!!!

Thanks Chas, Zed Head for constant advice!

I can move to next area now!




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Doh!  Been there done that!  The ZX I had the previous owner did that.  Glad you got it going. 

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