After purchasing 6 oem plugs from nissan, i decided to try to change my spark plugs. I have close to 60k miles on it.

I basiclly left the GAP of the pulgs as is from the box. I checked them and they were about .44 . After swapping the plugs mu car just misfires, and gurgles. When I tryto drive it it has almost no power and misfires. The gurgle happens in a rythm. :

Has anyone else run into this problem after changing their spark plugs? Or have any idea what may be causing my misfires and gurgle noise.


The the idol is bumpy and when I open the throttle ( when idol ) and then release the throttle, the RPMs drop to about 500k ( almost stalling ).

Thanks in advance

 

Sounds like at least one of the plugs is not firing. You said it gurgles with a repeating pattern? I would NOT run the car like that. Get it fixed first. The piston that is misfiring will blow unburned fuel to the cats. The fuel will burn at the cats and you will destroy them. So, don't drive.

If I were you, I would repeat the entire install. Sometimes we make small mistakes that we don't notice the first time. For example, you might have put the wrong ignition wire on the wrong coil. This would cause the car to fire out of sequence. Repeat everything this time and make sure you do it right and then try again.

If that does not reveal the issue and you still have problems, repeat the whole thing again, BUT put your old plugs back in. If that immediately fixes it, then you might have the gap set to high or a bad plug (not likely).

Hope this helps.

 

If the only thing you did, was change out the plugs for a fresh set, then you likely missed something on the re-install. I would check that your coil packs are plugged into the proper ignition connector, and that you have no vaccum leaks, disconnected lines, or something of that nature. A defective plug, out of the box...is extremely rare.

 

sounds like one of the coils isnt plugged in or pushed down good.


also the plugs have a crush washer on them, when they start to get tight you actually have to go another 1/3 to 2/3 s turn till they get nice and tight.

i had a plug back out a while ago and it ran the same way...

 

I checked them again. and The wires were inded feeding to the right cyclinders. The cumbustion sequence is indeed 1,2,3,4,5,6. This is from the manual. I rechecked the gap and even gapped the spacing a little lower to .040. I gapped it with a gapping tool that only goes to .040. I know that the gap is supposed to be .043 but the tool I used could measure that precisely.

I wondering if it could be a problem with one of the plugs or even one of the coils. I'm going to call into work tomorrow and get new plugs and coils from the dealer ship and try it again.

I suspect one of the plugs because I did try to regap the plugs intially when I first installed it. While trying gap I may have damaged it. I used this gapping tool and I may have pushed down on the electrode ( while using that tool incorrectly) . My brother also opened one of the ignition coils to look at it abnd made sure that it can seat a plug.

I do have straight pipes and true dual exaust and I found that one side of my exuast system does misfire. Since I have a direct connection from the headers to the tip of the exhaust, could that help me pinpoint the ( bad sparkplug or bad coil problem) or at least pinpoint which bannk of plug is causing the problem?

Thanks you all for you help.

 

Do you have the coils connected as follows....front of engine to back of engine.

passenger side 1,3,5
driver side 2,4,6

 

I think so. Unfortunatly there isnt an number of the 4 &6 wire. The 6 coil is upside down compared to the rest but it looks like its supposed to be that way. I can try to switch those two tomorrow and hopefully they wires when switched will reach the coils.

Thanks

 

my number 6 has a tag on it, hmmm.... yeah it sounds like some simple problem. the plugs you got should have been gapped properly to start with.

good luck!!

 

On the driver side, middle ignition connector actually goes to the rear cylinder#6. The connector closest to the firewall should connect to the middle cylinder #4 on the driver side.

Perhaps these are switched?

 

Thanks Sharif! this suggestion worked !!!!!!!! I did get them crossed. Now its purring like a healthy Z.


Thanks for everyones helps and replies........ this forum rocks!

 

Glad I could help, and that it was a simple fix.

 

damn sharif nice job on internet diagnostics.

 

This thread just saved me a lot of BS. Big thanks if posters are still around!

 

Can u plz add a picture of both sides of how it should look. Im having the same exact trouble on mines and i miss driving it

 

he hasnt logged in for over a year, may be waiting a bit for a pic

 

I know this forum is old. I'm having the same issue. I broke the coil to cylinder 6 and bought just a single one to replace it.. the wires are in the right places and still cant figure it out

 

18 years later, this thread, and specifically, this response single handedly fixed my problem in 2024. i knew something was fishy when i reinstalled those ignition connectors. something didn't smell right.

Thanks man! 1000X over, thank you.

 

I would just like to revive and thank this forum because this was my exact issue as well - having the 4 and 6 coils reversed. Shame on whoever designed the wiring, it seems so intuitive to have the #6 coil in the 4th position. Lol. The car is running great now. I was afraid I messed up somewhere much worse and more discretely during my spark plug replacement operation.

I love the 350z community's help. Thank you!

 

I would NOT run the car like that. Get it fixed first. The piston that is misfiring will blow unburned fuel to the cats. The fuel will burn at the cats and you will destroy them. So, don't drive.

 

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