# 1986.5 Hardbody -- No Spark to Start



## 89B12 (Sep 1, 2013)

Bought this extended cab D21 automatic from a friend of mine. I heard the truck running a couple of months ago, and it ran really good. It has 327k miles on the odometer. It died on him not too long ago and wouldn't start for anything. He offered to sell the truck to me as it sat, so I bought it.

All along, I was thinking it was fuel related. I stopped on the way home with the D21 on the trailer and put $10 worth of gas in. I rolled it into my garage and got a good charge in the battery. Turned the key, nothing. Then, I opened the breather and poured some fuel down the throttle body. Still nothing. 

Then, I checked for spark . . I pulled the #3 plug from the front on the exhaust side. The best I could do by myself, I laid the plug on the fender lip that sits just under the hood and turned the key. No spark. I'm confident that it was grounded enough to spark if it was going to.

Either way, upon searching this forum . . I haven't really found anything like my problem. I've never troubleshot an electronic ignition system, so I was going to ask you folks where I should start.

The check engine light isn't on, but could there still be codes stored in the ecu?

Thanks for any input!


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## rogoman (Dec 16, 2004)

Check for a spark at the coil. If no spark, any of the following may be bad:
- Coil
- Power transistor
- Fuse/fusible link
- Crank angle sensor in distributor
- ECU


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## 89B12 (Sep 1, 2013)

rogoman said:


> Check for a spark at the coil. If no spark, any of the following may be bad:
> - Coil
> - Power transistor
> - Fuse/fusible link
> ...


Thanks for your input!

I have just checked and verified that there is no spark at either coil. Had the wifey turn the key while I "loosely" connected the wire to the coil and neither one shocked me.

I feel like checking the crank angle sensor next, as I don't feel that both coils could be bad. Can Auto Zone test these or is it a guessing game at this point?


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## SPEEDO (Jun 9, 2003)

have you tried to pull any codes?


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## 89B12 (Sep 1, 2013)

SPEEDO said:


> have you tried to pull any codes?


I just pulled the codes . . I think.

I removed the passenger seat and unscrewed three screws holding down the computer. There is a small toggle switch on the rear (closest to the rear bumper) of the ecu. I turned the key to "on" and flipped the switch to "on".

The red and green indicator that were both steady on before I flipped the switch turned to this ::

1 blink red, 1 blink green

2 blink red, 3 blink green

2 blink red, 4 blink green

If I've read the codes correctly, the ecu indicates a bad crank angle sensor with the first code, the idle switch with the second, and the throttle valve switch with the third.

Sound like I did the correct procedure?


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## SPEEDO (Jun 9, 2003)

there is a sticky above, just to double check yourself


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## saudade (Apr 10, 2010)

Mine got the 23 and 24 codes as well. If you move the shifter around and press the gas pedal, they should go away. 

Check your cap and rotor.


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## 89B12 (Sep 1, 2013)

SPEEDO said:


> there is a sticky above, just to double check yourself


Thanks for the recommendation!





saudade said:


> Mine got the 23 and 24 codes as well. If you move the shifter around and press the gas pedal, they should go away.
> 
> Check your cap and rotor.


Thanks!

The cap looks good, but the rotor looks to be an older replacement. Hopefully the crank angle sensor that arrives tomorrow will correct the no-spark issue, and I can move on to getting this thing tuned up . . It really needs it!


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## 89B12 (Sep 1, 2013)

Replaced the crank angle sensor, truck started -- but with hesitation.

The idle is really choppy, there's a loud "popping" noise under hard acceleration, and the radiator looks like it's full of whole milk. My conclusion -- blown head gasket.

I'm going to rent a compression tester tomorrow to confirm.

Thanks for the information, y'all!


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## saudade (Apr 10, 2010)

Ouch... Does sound like a bad head gasket. There are a couple of current threads (including mine) on swapping head gaskets.

Good luck.


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## 89B12 (Sep 1, 2013)

saudade said:


> Ouch... Does sound like a bad head gasket. There are a couple of current threads (including mine) on swapping head gaskets.
> 
> Good luck.


I have already been reading your thread! I've done a ton of research online and found quite a bit of useful information. If a compression test does confirm a blown gasket, I am going to begin the tear down Monday night. I already suspected this, as when I looked over the truck at the time of purchase, I looked inside of the radiator before I made my price.

Not to hijack this thread, but is there a way to confirm that the head isn't warped other than taking it to a machine shop?


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## rogoman (Dec 16, 2004)

It's best to take the head to a machine shop as they have the tools to accurately measure the head for warpage. If you have access to an accurate straight-edge that's the length of the head and feeler gauges, then you can measure for any warpage. Head surface flatness should be less then 0.1 mm (0.004").


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## saudade (Apr 10, 2010)

Yep, what he said. I have a decent square and used it as my flat edge. 

Also make sure you completely remove any traces of the old head gasket from both sides before you check flatness.


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## 89B12 (Sep 1, 2013)

Thanks for y'alls responses!

In the few weeks past, I've torn the engine down and put it back together. All that I like is my Dad returning my torque wrench tomorrow to torque down the head bolts. After that, I hope she purrs!

Turns out mine was blown between cylinders 1 and 2. It looked just like yours, saudade . . A little chunk missing right at the smallest space between the cylinder walls.


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## saudade (Apr 10, 2010)

Glad you found the source of the problem. Let us know how it all works out. 

Mine still has a bit of an oil leak so I'm changing out the pan gasket this weekend. Otherwise it runs great.


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## 89B12 (Sep 1, 2013)

Welp, got it running . . But it hasn't left the garage! Lol.

Got everything back together. I'm almost certain I have all of the vacuum lines back in the correct place. I started the truck and it purrs . . At anything above an idle.

When you take your foot completely off of the accelerator, it stammers and dies. Now -- the funny thing is . . I got it to stop stammering last night and it actually idled. This tells me that it's most likely electronic. 

Remember those two other codes in post #5 . . Could either of those contribute to this problem?

Just for laughs, I called the local parts counter and the throttle position sensor is $122.

I don't want to fork out any more money unless I'm sure of the source. I'm going to do some forum searching and if no luck there, I'll start another thread.

Also, just so we're on the same page . . I've replaced the crank angle sensor, head gasket, spark plugs, thermostat, oil filter, fuel filter, and radiator cap.

Thanks again, guys!


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## 89B12 (Sep 1, 2013)

Two more things . . 

The ground wire that goes from the back of the valve cover to the firewall gets extremely hot during start attempts.

Also, there's a connector in the loom . . It's close to the oil filter. I don't remember unhooking it and have no clue where it goes. It's a gray connector with what looks to be a yellow wire with a green stripe and a solid green wire. It's a fairly short harness that goes to the mentioned connector. I can't find anything in the close vicinity that it snaps into.

Not sure if any of this is related to my current issues, but I wanted to note it in case it rings a bell to any of y'all.

Thanks again!


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## rogoman (Dec 16, 2004)

89B12 said:


> The ground wire that goes from the back of the valve cover to the firewall gets extremely hot during start attempts.


That's a sure sign that there's a problem with grounding from the battery. Make sure the ground cable from the battery is good and that it has a good connection to the engine block. You could end up with an electrical fire during starting attempts.


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## saudade (Apr 10, 2010)

I wondered about that same "stray" connector. Mine dangles too. 

There should be another ground bolted to the front of the cyl head on the intake side. It runs with the bundle just in from of the head.

Double and triple check the vac lines connecting to the air cleaner.


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## 89B12 (Sep 1, 2013)

rogoman said:


> That's a sure sign that there's a problem with grounding from the battery. Make sure the ground cable from the battery is good and that it has a good connection to the engine block. You could end up with an electrical fire during starting attempts.


Thank you!

I will check my battery ground and relay my findings.


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## 89B12 (Sep 1, 2013)

saudade said:


> I wondered about that same "stray" connector. Mine dangles too.
> 
> There should be another ground bolted to the front of the cyl head on the intake side. It runs with the bundle just in from of the head.
> 
> Double and triple check the vac lines connecting to the air cleaner.


Okay, that makes me feel better about the connector . . I knew I didn't remember taking it loose.

I checked the vacuum lines for a 3rd time last night, thoroughly following a colored diagram from "Nissan Nut" that came about through a Google search. By what I'm seeing, everything is in place. 

I am going to "play" with the distributor timing a little bit after checking that battery ground . . If that yields no positive results, I am just almost to the point of having my mechanic take a gander at it.

Thanks again, y'all!


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## 89B12 (Sep 1, 2013)

Well, I checked my grounds and found a big problem.

I remembered when I did the tear-down, someone had messed up the connector on the intake-end of the ground cable that comes from the battery. It was a little loose and wrapped in electrical tape. I removed the electrical tape and found the end hanging by a "thread". I went to the parts store and found an aftermarket end that would work for my application and installed it. Wholia! Started up, but wouldn't idle. After I fanned the accelerator a few times, it idled.

Now, yesterday, after grasping for many straws, I screwed in the idle-stop screw in the throttle body. The truck didn't idle just right, so I put it back to where I thought I had it. Also, I had to remove the distributor to install that crank angle sensor weeks ago, so it never got put back in the proper place. I went to time it with my light, and I couldn't see the marks, even after I tried to clean the area. So, with that, I set the timing to where it sounded good by ear, and let it idle awhile.

It idled fine. It stammered just a time or two within several minutes . . I just wrote that off as something working through it where it'd been sitting so long. After 20+ minutes of idling, I decided to take it around the block.

Not far after leaving my driveway, it started "bucking". The engine would cut out, I could fan the accelerator and with the momentum pushing through the transmission, it would fire back up. This truck is an automatic, by the way.

After several rounds of that, trying to make my way back to the house, it quit. It will restart, then quit, just as it did before I fixed the ground, with the exception of now, I can't keep it running for nothing. It's sitting by the curb about 400 yards from my house.

When I first brought the truck home, I pumped $10 worth of gas in it while on the trailer, so I know that it has two gallons, at least, left in it. I will check the fuel flow a bit later before I try and restart it.

It seems to me that when it got to "operating" temperature is when it really got to acting up. It could be something else, though . . At this point, I'm clueless.

I'm going to let it sit next to the curb until the early afternoon to give me some time to think. I plan on going back and reattempting to start it once more. If I can't get it running good enough to come here, at this point anyway, I've decided to have to towed to my mechanic's.


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## 89B12 (Sep 1, 2013)

Let the truck sit awhile . . It cooled back down. I walked back down to it and started it up. It wouldn't hold an idle for anything, but I managed to get it back home.

Once back home, I started pondering at the possibilities of what could be ailing this thing . . .

I replaced the ground wire from the valve cover to the firewall, just in case . . No change. I then decided to recheck all of the vacuum lines once more, this time however, verifying their condition.

I removed the breather and started running my finger across each line . . BINGO!

I found a big hole in the line that runs from the bottom of the throttle body to the breather. I replaced that whole line and then the truck idled, but very rough. However, at least with it idling, I could find other leaks. After finding and sealing off four vacuum leaks, this thing fires up and purrs!

I obviously should've checked these lines more thoroughly when I connected them, I just couldn't imagine them being in the shape they were in. However, this is an '86. They are very old . . For vacuum lines! 

I still don't have the timing set with a light . . I'm going to dig around tomorrow or Tuesday and try to find those marks. At least now, I'm able to stroll up and down the road.

Thanks, y'all . . For everything! I wouldn't be to this point without you guys!

How can I give back?


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## saudade (Apr 10, 2010)

Glad you got it working fine.


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## 89B12 (Sep 1, 2013)

Update ::

I re-torqued the head after a week of commuting and after a thousand or so miles now, everything is still going really good. I ended up doing some trading with my Dad, as he's been wanting a good pickup for the last few years. He bought an '84 King Cab brand new with the Z24/5-speed combo and made a lot of memories in that truck. He had 156k miles on it in 2000 when a fast-lube chain left two oil filter gaskets on it and it threw a rod on his drive home.

Although this 86.5 isn't in quite the shape his '84 was when he parted with it, he's happy as a lark again.

Now, I've got to figure out how to get rid of this DeVille . . .


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## 86HARD (Aug 18, 2014)

89B12 said:


> I just pulled the codes . . I think.
> 
> I removed the passenger seat and unscrewed three screws holding down the computer. There is a small toggle switch on the rear (closest to the rear bumper) of the ecu. I turned the key to "on" and flipped the switch to "on".
> 
> ...


89B12 - I just replaced the ECU in my D21, its a V6 manual but same year. I'm having an issue with the ECU draining my battery. The two lights, the red and green both stay on all the time unless the truck is actually running. If I switch the toggle to "Off", the trouble codes (13, and 43) continually blink. Either way, this kills the battery within an hour. I know the battery is good, it's brand new. I know my alternator is good, pushes 14V at idle. I know it's the ECU because with a multi-meter on the battery while the truck is off, I can watch the voltage drop about .1 every 30 seconds. As soon as I disconnect the power to the ECU, the voltage drop stops. 

My question for you is, do you remember if the lights on your ECU were always on? Did they turn off when the truck was off?

Thanks for your time and I'm glad you got her going. Sounds like a real battle.


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## smj999smj (Jan 1, 2006)

I ran into a Z32 300ZX that did the same thing in 1998. Battery kept draining after a couple of days. Intermittently, the ECM would stay power-up even after the key was removed (both LEDs stayed on). Replaced the ECM and no more problems.


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## 86HARD (Aug 18, 2014)

smj999smj said:


> I ran into a Z32 300ZX that did the same thing in 1998. Battery kept draining after a couple of days. Intermittently, the ECM would stay power-up even after the key was removed (both LEDs stayed on). Replaced the ECM and no more problems.


NOOO!!!! I was really hoping not to hear that. It took me 9 months of searching and waiting for a used ECU that would work on my truck to pop up. I wasn't about to pay Nissan $800 for one or even $500 for a re-man.

I was told that it has to be an 87', manual, V6, Single Rear Wheel, 2WD that the ECU came out of in order to work correctly with my truck and I was not having much luck finding one. It seems a lot of the V6's either came with Auto's or were 4WD.

I may just isolate the wire supplying power to the ECU and put in a toggle switch since everything else is working correctly.


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## smj999smj (Jan 1, 2006)

There should be several power supplies to the ECM. You'll need some power to retain the self-learning function. Just power to the ECM will not run down the battery. What killed the Z I worked one was that it was energizing engine some engine control components, and that what was really the draw that was draining the battery, it was just that the ECM wasn't always cutting power to them when the ignition switch was turned to off. Because of the vast number of ECM's Nissan used, you can now understand why they use programmable units in later models. One part can cover multiple applications based on the software programming installed on them, which can be easily updated if they find a need to change the software to fix an issue or adjust parameters.


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## 86HARD (Aug 18, 2014)

smj999smj said:


> There should be several power supplies to the ECM. You'll need some power to retain the self-learning function. Just power to the ECM will not run down the battery. What killed the Z I worked one was that it was energizing engine some engine control components, and that what was really the draw that was draining the battery, it was just that the ECM wasn't always cutting power to them when the ignition switch was turned to off. Because of the vast number of ECM's Nissan used, you can now understand why they use programmable units in later models. One part can cover multiple applications based on the software programming installed on them, which can be easily updated if they find a need to change the software to fix an issue or adjust parameters.


That makes much more sense. I was wondering how these little lights could be drawing that much voltage. So you're saying the ECU is actually bad even though everthing runs and functions correctly. It's keeping something running when the key is shut off.

The the wiring harness that supplies the power has appro. 12 wires going into the ECU. I only assume this is where they power is coming from because when I pull this plug, the lights on the ECU shutoff and the voltage drop on my battery stops. Unfortunately you're saying that it's not just one of these wires that is providing the power? There are multiple? I'm just thinking "red-neck" fixes here becuase this truck is literally used a handful of times a year. What about a switch for the batter ground instead of a switch for the ECU power?


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## smj999smj (Jan 1, 2006)

A battery cable ground switch would probably be an easier fix. You still might lose the self-learning information of the ECM, but fortunately they come with a base setting and since you only use it a few times a year, it really won't matter much.


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## 86HARD (Aug 18, 2014)

smj999smj said:


> A battery cable ground switch would probably be an easier fix. You still might lose the self-learning information of the ECM, but fortunately they come with a base setting and since you only use it a few times a year, it really won't matter much.


Because it's obvious you KNOW what you speak and are not just giving me the common "well I heard from a guy..." stuff you can sometimes get on a forum, if I do decide to install a toggle for the battery ground, do I need to make sure the switch can withstand a certain amperage? I know you can get swtiches for 15A, 20A etc... so I just want to make sure I'm not going to create a fire hazard.

I have another electrical issue that I've been trying to diagnose. For some reason, my left front blinker is not working. The drive light in my bumper works but does not blink. It doesn't blink when the hazards are on either. The rear funtions correctly. When I turn on the blinker, I get the fast blink inside like it does when a bulb is out but I know the bulbs are all good. Also, the orange drive lights on either side of my headlights are not working; no power. I don't remember if these blink or not or if they are just drive lights. From what I've read, this could all be caused by the light switch itself and that I should first try to replace that. Do you agree? 

Thank you so much for all your help and advice. I'm not a total novice in the garage but I'm also by no means a mechanic. I change our oil, replace the odd window regulator in my wifes BMW, replace valve cover gaskets and radiators but when it comes to electrical... I'm worthless! It's really nice to get knowledge not just advice.


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