6.0PSD

Since I had the time today I decided to see what the front plugs look like so that I could get an idea what may also be going on in Bank1... I'll let the pics tell the story...


I knew there was a slight oil sweat coming through the tube seals but didn't expect to see this glad I pulled them...


Is this what is expected of all that fuel treatment I have run through... I didn't expect it but here is the proof... What does all the famous fuel additives really do then?



Cleaned the one up with wire brush and carb cleaner to show difference... Did the same to the other two after... I refuse to change just the front ones to the new ones I have, until I can get more time to do the rear first so I cleaned and reinstalled them... I have no idea if previous owner ever changed these or the rears but after cleaning they don't look bad... Hope to at least have time soon to pull at least one rear, the easiest of course...


Different angle to better show tips...

Tried to get a clear piston top pic... This is cylinder closest to TB, #2... #2 & #6 looked the same...

Center #4 cylinder

By looking at these pics can anyone give any details as to why there was so much calcium looking material stuck to tip, had to carefully scrape it off and it was hard. Is it all the multiple doses of fuel additives? I expect the rears to look the same or worse if the previous owner never changed them.

fastnoypi

your tube seals are definitely dead if you are getting oil on the plugs. The ash is typically from oil or poor fuel. If you haven't figure out by now, most of those fuel additives are snake oil. Stick with any major brand gas, and you will have all the detergents you need.
When you have time, you might as well remove the intake manifold to have all the space in the world to replace and torque your plugs correctly, and put in new tube seals and valve cover gasket. You won't need to revisit for another 100k+ miles for your next plug change.

6.0PSD

I was hesitant to start looking at the rear plugs because of all I read about how hard they were to get to, but I have to say it is not that bad to change them with the right tools and patience, glad I finally pulled them...


Completely removed the cruise cable and bracket...



Removed the pcv valve/hose... Removed the 12mm ground nut... Removed the little vacuum hose attached to that valve, I then tied up that valve with a plastic bag up out of the way(used#3 phillips bit to remove two screws holding valve to intake)



Other than leaking tube seals I did not expect to see the rear plugs in so much better shape compared to the front... They loosened up wayyyyyyyy to easy...



Wire brushed them clean then hit them with carb cleaner... Threw them back in until I can figure out what is causing fuel eco issues, don't want to screw up my new ones... I don't mind changing them at anytime as I don't think they were that bad to change...

6.0PSD

I used an actual spark plug socket that has a rubber boot inside it to hold plug to it, that piece of rubber in socket may get stuck to plug after it's installed and so it is best to glue it to socket with a little silicone overnight otherwise plug will need to be pulled back out to get that boot off, you also don't want to just drop the plugs down the holes as it may affect the gap... The swivel and a 3" extension attached to socket as shown worked great without having to separate them, swivel makes it around the tight corners back there perfectly and so made it a super easy to remove/install plugs...

I also removed the cruise control actuator/servo box, or whatever it's called, managed to snap 2 of the 3 studs holding it down... Had those studs soaking in penetrating oil for 30 minutes but still snapped...


And finally everything went back together the same way it came apart... All 3 of my rear tubes are leaking, but I'll take care of that in time... plugs were a bit too loose for my likings when I tried to remove them and may have been under torqued when previous owner had car... Took it out for a drive and feel a little more power at lower rpm's, hope it's not a placebo effect... Time will tell if the rear plugs were my fuel eco issues... Injector rebuilds will be next if issue still exists...

I feel I am the only one posting to my own threads and hope I'm not overposting with so many pics... I just feel that pics tell the story better than words and hope they don't bore everyone but instead figure they may help out someone one day... I'm just trying to get any help I can with my issues...

Forgot to mention that when I was about to reinstall the pcv valve hose to the intake nipple I happened to notice crusty dark junk covering a lot of the inside of nipple so I took a wood screw and dug a lot of crap out of it, it was nearly blocked... Will need to pull that side cover off soon to check out the insides of it, hope there are no small parts in there that may fall off, have to get the right gasket first.

maxSteel

The cleaned plugs look great. I probably would have changed them just because its a pain to get them out.

Here is some guidance from NGK on how tight they need to be.
https://www.ngksparkplugs.com/about-...g-installation

artbuc

It is an absolute no-no to wire brush and re-install iridium plugs. Not sure why because I never looked into it but that warning is clearly stated in the FSM and supported by NGK and Denso.

http://www.globaldenso.com/en/produc...ech/qa_23.html

http://www.aus300zx.com/forum/archiv.../t-276584.html

6.0PSD

Thanks for the link... I didn't think they were that bad to get to... Took me about 15 minutes to remove all the surrounding parts to get better access from both sides, will take me less time next time as I now know exactly what needs removing... Another 15-20 minutes to remove all three plugs & coils...

Have to get the correct torque # for the new oem denso plugs I have waiting to get in there, I have a 1/4" torque wrench that I hope to sneak back there to the new ones torqued right... I'm just trying to keep the new ones out of there for a little while longer, I'm@ 106,700 miles on odometer so hoping to get new plugd in @110k

6.0PSD

Thank you for your knowledgeable response, I did not know that and now I do... Glad it was brought up and so I will never do it again in the future and hope it is a lesson learned for anyone else reading this and also does not know... I have to say though, the car is a little better than previous so it could have been the really loose plugs in the rear, I could probably have them removed without the ratchet, or just about, as they were that loose...

So it could very well be that once I replace plugs that all my issues will be resolved...

Issue I'm having is that the plug tubes are all leaking and need more time to do the valve cover gaskets/tube seals before I replace plugs, don't want to pull the new ones again to clean the tubes... So hope to do everything on or before 110k miles on odometer... Just happy to see a little bit of better fuel eco, but still not what I'm hoping for...

6.0PSD

Had some time today to mess with the plugs and decided to pull front bank 2 cover as well...

Bank 1 rear plugs in order 1 3 5 as they came out after I had last cleaned them... Odometer is now @ 106,950

Front Bank 2 plugs in order 2 4 6

6.0PSD

Tools I used to remove/install




I removed everything just as the last time I did this except this time I left the cruise servo motor in place, I just worked around the cable...

I used the same 3/8" ratchet setup as I did before then I used the 1/4" torque wrench to torque it down...

I was able to do all 3 rears with this torque setup pictured but had to first snug the plugs slightly with the standard ratchet just enough so that I could finish with the torque... Because of all the joints it was a bit tricky to get the setup to work as I had to hold that little 1/4 socket with one hand while I tried to get the ratchet to click back enough to tighten, hope I made sense of this..

The center plug I had run the ratchet from the left side as I was working on engine... I little more work but I did accomplish it just fine with some patience... Rx300 called for 13ft lbs and Rx330 is 18ft lbs so I decided to set it to 168in lbs which is around 14

salimshah

Being a purist ... no flex coupling on a torque wrench. :^)

Salim

6.0PSD

a less jointed, direct to plug setup would be best for torque but doubt the accuracy would change all that much to be an issue... The force still needs to end at the plug when it gets to that set pressure on wrench... I figure if the torque wrench setup I used fits then it will be more accurate than guessing with a standard ratchet...


I just reread the way I explained how I torqued and tools used and want to explain a little better as it feels like I said I used all those tools pictured to torque the plugs...

To pull the plugs I used the 3/8 ratchet with 3/8 extension(3" long) attached to swivel and socket... Then used this same setup to set plugs back in with a very light tug as to not get close or exceed manufacturers torque... Then I removed the 3" 3/8" extension from the swivel to instead use the other smoke colored extension pictured in its' place, which has a 1/4 shaft to a 3/8"socket which then allowed the 1/4" torque wrench with a 1/4" socket to operated in a straight line with it...

In a straight line as I did, it is safe to say the torque wrench will do its' job fairly accurate with all the joints, but if the swivel had to operate at any angle other than straight then accuracy would become way off