1984 4x4 pickup failing spark from either coil

[Blue720]

Ran great last summer. Left it sitting at the cabin. Lots of rain and snow but its always been a good runner. Tried to start it the other day and it just cranks. Turn the key, the lights light up as usual, I can hear the fuel pump, and it cranks like normal, but doesn't start. Lifted the hood, pulled coil wire just out of it's socket, and had someone turn the key, got no spark. Pulled the other coil wire, same thing. Got out multi-meter and checked positive side, got 10.8 volts on both coils. Checked the 3 pole junction, got 11 volts, 3 and 3 respectively. Checked primary resistance on both coils and it was 1.1 on both. Checked secondary on both coils and it wavered around 6-8. Got inside the cab and pulled first fuse, cleaned and dried it up, put it back in, still nothing. Figured the fuse is ok, and the coils, but I get no spark.  Took a wire and ran it from positive pole of the battery to the 3 pole junction high voltage pole and tried again...no start. Pulled the distributor cap, everything looks fine, put it back together and still no start. 

Running out of ideas, any help greatly appreciated

Brett

[datzenmike]

Put the jumper from battery to positive terminals on coils back on and test for spark on both. If none make sure distributor is tightly mounted to timing cover and well grounded. 

 

If yes, there is spark, check for spark at one of the plug wires on the intake and the exhaust side. I just put an old spark plug in the end and hold against the grounded intake or exhaust manifold.

 

If spark on both, probably flooded from trying 

[Blue720]

8 hours ago, datzenmike said:

Put the jumper from battery to positive terminals on coils back on and test for spark on both. If none make sure distributor is tightly mounted to timing cover and well grounded. 

 

If yes, there is spark, check for spark at one of the plug wires on the intake and the exhaust side. I just put an old spark plug in the end and hold against the grounded intake or exhaust manifold.

 

If spark on both, probably flooded from trying 

 

Will do. Thank you so much for the reply. Heading out to the cabin this morning, will report back this evening. Is it common to see a voltage drop from the 12.6 at the battery to about 10.8 at the coil terminals? I found those numbers a bit concerning. Not sure how I'm losing nearly 2 volts, but I had never tested before because this rig has always started and run well. I was thinking maybe some corrosion or moisture at the terminals. The fuse block showed 12.3 so I lost some there and I was thinking it was just all adding up. Would the clutch switch effect this? I've never really looked at it, but I've noticed in the past that I had to make sure my foot was all the way to the floor before it would start up. 

Again, thank you for the information.

Brett

[datzenmike]

A jumper wire directly from the battery will either solve the spark problem or not. If it does that voltage drop is the problem.

 

The clutch interlock can be defeated for test purposes. Have a care as there should be two switches on the clutch pedals. One for the starter interlock and one for the fuel shut off.

[Blue720]

Just now, datzenmike said:

A jumper wire directly from the battery will either solve the spark problem or not. If it does that voltage drop is the problem.

 

The clutch interlock can be defeated for test purposes. Have a care as there should be two switches on the clutch pedals. One for the starter interlock and one for the fuel shut off.

 

thank you. I'll have to look at that switch today. Maybe jumper them both. Fuel doesn't seem to be a problem though as the pump pumps, and the carb fills up, I can smell gas after cranking a bit.

[datzenmike]

Don't mess with the fuel shutoff switch. Under certain conditions it prevents stalling when down shifting. 

[Blue720]

1 minute ago, datzenmike said:

Don't mess with the fuel shutoff switch. Under certain conditions it prevents stalling when down shifting. 

 

I've never looked down there, is it obvious which one is which?

[datzenmike]

Use a jumper on both and see if the starter works with one of them.

 

The switch may just need adjusting. There should be continuity through the interlock switch when the pedal is all the way down. Interlocks are for idiots just like the buzzer to remind you your key was left in the ignition. My '70 Dart had one. I disconnected it because if you stalled and couldn't get the engine running you could still put in gear and use the starter to move the vehicle out of harm's way. 

[Blue720]

1 hour ago, datzenmike said:

Use a jumper on both and see if the starter works with one of them.

 

The switch may just need adjusting. There should be continuity through the interlock switch when the pedal is all the way down. Interlocks are for idiots just like the buzzer to remind you your key was left in the ignition. My '70 Dart had one. I disconnected it because if you stalled and couldn't get the engine running you could still put in gear and use the starter to move the vehicle out of harm's way. 

 

Didn't go as planned. Girlfriend in the car, cranked while I measured stuff. I was concerned about the 2 volt drop between the battery to the coils, and another 1/2 volt drop while cranking. So I decided to check and clean all the terminal connections from the battery and to the coils. Put a wrench on the positive side of primary coil and it snapped off without applying hardly any torque. Negative side came off fine. Put a wrench to the positive side of the secondary coil and exact same thing happened...the whole pole snapped off, negative came off fine. I'd hit the connections with WD40 and neither were clearly corroded. 

All that said, I need two new coils before I do anything else. Any recommendations greatly appreciated

Brett

[banzai510(hainz)]

1 minute ago, Blue720 said:

cranked while I measured stuff. I was concerned about the 2 volt drop between the battery to the coils, and another 1/2 volt drop while cranking.

there is alot of voltage drop during cranking. what are you looking for? these are low ohm coils. so if spark is coming out of them I would say they good.

[Blue720]

5 minutes ago, banzai510(hainz) said:

there is alot of voltage drop during cranking. what are you looking for? these are low ohm coils. so if spark is coming out of them I would say they good.

I wasn't getting any spark from either coil.

 

now I need 2 new coils

[Thomas Perkins]

I have been using Auto Zones coils for over 10 years.They are Awesome.Plus lifetime warranty.

[Blue720]

As I search this site, I see a lot of discussion about having the 'appropriate' coils for these trucks. I'd like to just pick a winner from whatever is available at the local O-reilly's or Autozone, but I'm not sure that's my best option. I found that Nissan doesn't even make them available anymore, so I guess OEM is out of the question. 

 

any feedback greatly appreciated. I need to get this rig running soon so I may just pick from what they have

Brett

[datzenmike]

Appropriate? Well not the cheapest, you want something equivalent to the stock one that almost never fails.

 

Points coils are around 1.50 ohms primary and an additional 1.5 ohms ballast resistor for a total of 3.0 ohms.Found on Datsuns to '77.

EI or electronic ignition use a .75-.1.0 ohm coil and no ballast. Found on '78 and up Datsuns.

[Thomas Perkins]

One thing about Auto Zone coils.You can return parts for a free replacement with no questions asked cause they dont test them.Same as distributor caps and rotors that have lifetime warrantys So every few years you can get free new ones.Many parts you can do that.Radiators,water pumps, both brake and clutch master cylinders.Slave cylinder.I use to get heater cores from them but they no longer sell them.After installing 2.They gave me a money refund.I had my 720 for 32 years and only had to buy one radiator, one starter,alternator and other parts I have listed.I put a Auto Zone radiator in my wife's 04 Lincoln LS car over 6 years ago.Still doing good.Same as my Nissan  plastic one.Her original one was plastic.Her's  has no radiator cap.

 

Edited April 21 by Thomas Perkins

[Blue720]

I replaced both coils with a couple new ones from Autozone, cleaned up all the contacts and still get the same readings I got when I first started, and still no spark coming from either coil. Still not sure why I'm not getting 12.6 volts to the coils. For some reason I get 11.1 and 10.8 and all my connections are clean. 

 

I'm assuming now that the IC Ignition unit inside the distributor may be the problem. I found a manual online and it says when testing it I should be getting >11.5 volts at terminals I, B, and E, but I'm not getting that. The manual describes disassembly of the distributor in order to replace this part and it seems a bit invasive.

 

Anyone have experience doing this job? 

https://asavage.dyndns.org/Nissan/display1.php?Path=720/FSM_1984&db=Nissan&table=720_FSM_1984&Page=20-037

Edited April 26 by Blue720
added link

[Blue720]

anyone know why there is such a vast range in prices for an ignition control module?  I see them new from $46 to nearly $500

 

?

[datzenmike]

Chinese knock offs. With cheaper price you get reduced reliability. Search the junk yards for a used Z24 distributor. Cheaper.

[Thomas Perkins]

Their are 2 different types.The one on my 85 is real expensive.Looks different that the other type.

[Thomas Perkins]

Their are 2 different types.The one on my 85 is real expensive.Looks different that the other type.Here is the type I have.Here is a new Nissan one for sale.

 

 

 

Edited April 28 by Thomas Perkins

[Blue720]

40 minutes ago, Thomas Perkins said:

Their are 2 different types.The one on my 85 is real expensive.Looks different that the other type.Here is the type I have.Here is a new Nissan one for sale.

 

 

 

That one actually looks like the one I have. I went on the Nissan site and they are all discontinued, but the part numbers were there. I then went an x-ref'd those part numbers and found some that claim they are equivalent, however when I look at them, they have more terminals than mine. I see only 3

https://photos.app.goo.gl/CQksDzCMmmhz7zx86

 

hope that pic can be seen.

[Thomas Perkins]

Here is mine.Same as the link I sent to buy a new Nissan one.Mine has 4 wires.I put a new big o ring on it as you see.To seal if to keep moisture  and dirt out.The one built on the Distributor dry rotted and parts were missing.So scrapped it all of and this one fits perfect.I bought a ten pack of them.This Distibutor part  that Nissan  still has is real high on the after market parts.I have 405,000 miles on my distributor.Clean ain't it.Never had to set time on it.

 

 

 

 

Edited April 28 by Thomas Perkins

[Blue720]

3 minutes ago, Thomas Perkins said:

Here is mine.Same as the link I sent to buy a new Nissan one.Mine has 4 wires

 

 

 

 

For some reason it let me post this pic. 

I found this info on the Nissan site...it seems to show only 3 terminals. Which the manual I posted above seems to confirm by showing to check voltages at terminals I, B and E. Some of the x-ref'd parts I found had 4 or 5 terminals, not sure what they might be for.  

• Transistor Ignition Unit
  22020-61W00

  • HITACHI
  • Production Date: 01/1983-06/1984
  • Fitting Vehicle Options: Z20
  • Replaced By: 22020-61W03

   
• 22020-61W02
  • HITACHI
  • Production Date: from 07/1984
  • Fitting Vehicle Options: Z20
  • Replaced By: 22020-61W03

   
• 22020-D0200
  • HITACHI
  • Production Date: 11/1982-06/1984
  • Fitting Vehicle Options: Z24
  • Replaced By: 22020-V5401

   
• 22020-V5400
  22020-V5400
  Transistor Ignition Unit

  • HITACHI
  • Production Date: 11/1982-06/1984,from 07/1984
  • Fitting Vehicle Options: Z24
  • Replaced By: 22020-V5401

[Thomas Perkins]

Do you have the 2.4 engine.Rock Auto parts has the one like mine and it shows my part number to.But it is high dollar.If yours is like mine get the Geniune Nissan one for 169.73 or let me know what the part number to your's is and I will find you a real Genuine Nissan one.Shipping is high.Here is Rock Auto Parts like mine.They have other types too.This one is just like mine.

Edited April 28 by Thomas Perkins

[Thomas Perkins]

When Nissan here in USA had them.They were over 300 dollars.