Jump to content
SAU Community

Plug Fouling

66yostagea

By 66yostagea,
in Four Door Family & Wagoneers

 Share

Recommended Posts

66yostagea Grand Master

66yostagea

Posted
Posted

Since fitting the forward facing plenum the plugs foul in less than 2000ks. I pull the out clean them up and put them back everything fine goes like a rocket. Then she went again today. BCPR7ES gapped0.8 are what I have been using. When they come out they are totally sooty. Black as. Have a set of the pre plenum change plugs that had done 7000ks, they look OK. Still see the white of the insulator.

How do I fix this? I have a DFA and hand controller. Will this fix it? Or is there some other sensor that is off its face.

Your thoughts would be welcome.

Link to comment
https://www.sau.com.au/forums/topic/339664-plug-fouling/
Share on other sites
DeanR33 Enthusiast

DeanR33

Posted
Posted (edited)
Since fitting the forward facing plenum the plugs foul in less than 2000ks. I pull the out clean them up and put them back everything fine goes like a rocket. Then she went again today. BCPR7ES gapped0.8 are what I have been using. When they come out they are totally sooty. Black as. Have a set of the pre plenum change plugs that had done 7000ks, they look OK. Still see the white of the insulator.

How do I fix this? I have a DFA and hand controller. Will this fix it? Or is there some other sensor that is off its face.

Your thoughts would be welcome.

I don't know much about forward facing plenums, but can't see why it should foul all your plugs.

It could be your o2 sensor, but I would expect poor running too if it were that. Also coolant temp sensor. You can meter the temp sensor to see whether it's giving the correct readings, but the o2 sensor isn't that easy, though the voltage should cycle on it.

Another possibility is plugs that are too cold, though I wouldn't say that sevens like you have would normally cause this.

Even maybe FPR

Are you doing lots of short runs? After a good motorway run, the plugs shouldn't be black.

Basically, we need more info on what level of tune/mods you have and how it's running in general to give more advice.

Edited by DeanR33
Link to comment
https://www.sau.com.au/forums/topic/339664-plug-fouling/#findComment-5486475
Share on other sites
pipster11 Grand Master

pipster11

Posted
Posted

pull the plugs and coils out, disconnect the cas and crank it over

watch the plug holes for any vapor, because the cas isn't connected the injectors shouldn't fire but if you see vapour coming out there is fuel getting in = injector seals

i'm guessing that its a s1 here = same injectors as r33's which sit in the fuel rail and fuel flows around them unlike r34/s2 injectors which have the hose on one end

you may need to get the fuel rail machined or just get new seals

Link to comment
https://www.sau.com.au/forums/topic/339664-plug-fouling/#findComment-5487387
Share on other sites
66yostagea Grand Master

66yostagea

Posted
  • Author
Posted
pull the plugs and coils out, disconnect the cas and crank it over

watch the plug holes for any vapor, because the cas isn't connected the injectors shouldn't fire but if you see vapour coming out there is fuel getting in = injector seals

i'm guessing that its a s1 here = same injectors as r33's which sit in the fuel rail and fuel flows around them unlike r34/s2 injectors which have the hose on one end

you may need to get the fuel rail machined or just get new seals

Yes, it's an S1 Auto.

I'll give that a try. Anything actually.

If it is leaky seal(s) would that not impair performance all the time? And would some plugs be sooty and others not. In my case all the plugs are Sooty.

Link to comment
https://www.sau.com.au/forums/topic/339664-plug-fouling/#findComment-5487466
Share on other sites
66yostagea Grand Master

66yostagea

Posted
  • Author
Posted
pull the plugs and coils out, disconnect the cas and crank it over

watch the plug holes for any vapor, because the cas isn't connected the injectors shouldn't fire but if you see vapour coming out there is fuel getting in = injector seals

i'm guessing that its a s1 here = same injectors as r33's which sit in the fuel rail and fuel flows around them unlike r34/s2 injectors which have the hose on one end

you may need to get the fuel rail machined or just get new seals

Yes, it's an S1 Auto.

I'll give that a try. Anything actually.

If it is leaky seal(s) would that impair performance all the time? And would some plugs be sooty and others not. In my case all the plugs are Sooty.

Link to comment
https://www.sau.com.au/forums/topic/339664-plug-fouling/#findComment-5487467
Share on other sites
66yostagea Grand Master

66yostagea

Posted
  • Author
Posted

What I have done today is to run a less restrictive line to the fuel PRV. It could have been choking a bit.

Cleaned the plugs and bingo.

Started first kick and was able to balance 50c piece on the top radiator support. So its smooth.

If it plays up again I'll try the CAS check of Tom. Just trying one thing at a time. Too often I have done too much stuff and dont know what fixed the problem.

I'll keep you posted.

Link to comment
https://www.sau.com.au/forums/topic/339664-plug-fouling/#findComment-5487626
Share on other sites
pipster11 Grand Master

pipster11

Posted
Posted

it'll probably run ok buy be uber rich

i put a safc on my 32 and turned the mixture right up and it still ran fine (+20% fuel) and sounded smoother but sounded like it had bogged down a bit

see how it goes, if they foul again then its something to look at

could have been that when you were installing the f-facing plenum the injector seats were off or the o-rings no longer fit

Link to comment
https://www.sau.com.au/forums/topic/339664-plug-fouling/#findComment-5489690
Share on other sites
66yostagea Grand Master

66yostagea

Posted
  • Author
Posted
it'll probably run ok buy be uber rich

i put a safc on my 32 and turned the mixture right up and it still ran fine (+20% fuel) and sounded smoother but sounded like it had bogged down a bit

see how it goes, if they foul again then its something to look at

could have been that when you were installing the f-facing plenum the injector seats were off or the o-rings no longer fit

I did not pull the injectors out and replace the o rings but I did put in the new plastic insulators. The question I have about the injectors is that if one did leak internally would it make all the cylinders run massively rich??? I would guess that if the prv was not working properly that all plugs would foul.

Link to comment
https://www.sau.com.au/forums/topic/339664-plug-fouling/#findComment-5490176
Share on other sites
66yostagea Grand Master

66yostagea

Posted
  • Author
Posted
shouldn't cause them all to foul

what do you mean by the plastic insulators?

Nissan call them "Insulator Injector" From memory it seals the injector body to the inlet port and insulates it from the heat of the plenum to prevent vapourisation I guess. Its on page EN108 of the R33 manual.

I have had R30s since new in 1984 and the only problem I ever had with them was the prv. When it spits the dummy it will start but not run over 1200revs.

I'll go for a 200k run and see how the plugs look when I get back.

Link to comment
https://www.sau.com.au/forums/topic/339664-plug-fouling/#findComment-5490982
Share on other sites
  • 1 month later...
66yostagea Grand Master

66yostagea

Posted
  • Author
Posted

I refurbished all the earthing leads and put in extras. The earth wires at the front of the plenum were not tight down as the bolt had bottomed. That seems to have fixed the sooty bit, but it still got its knickers in a knot, now and again, for no apparent reason.

Checked all the vac/boost lines and found the one to the PRV and to the inlet of the MBC and to the actuator were a bit sus. So clipped them.

Its early days yet but on a couple of 40k trips up and down the mountain it has not missed beat.

One suggestion for folks wanting to fit a forward plenum, the connections for the lines at the back of the plenum come out at rightangles.

I would suggest putting in a right angle fitting then they would be more upright an accessible.

Link to comment
https://www.sau.com.au/forums/topic/339664-plug-fouling/#findComment-5550261
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • GTSBoy
      What brakes on R34 GTT(Europe)

      By GTSBoy · Posted

      I would just put EBC back on the "I would not use their stuff" pile and move on.
    • Duncan
      What brakes on R34 GTT(Europe)

      By Duncan · Posted

      Can I suggest you try EBC directly again and link them to as many competitor catalogues as you can to show their listing is incorrect, eg https://dba.com.au/product/front-4000-series-hd-brake-rotor-dba42304/ If you have access to an R33 GTST VIN and your VIN, you could also use a Nissan Parts lookup like Amayama to show them the part number is different between 33 GTST and 34 GTT which may get their attention
    • Kapr
      What brakes on R34 GTT(Europe)

      By Kapr · Posted

      So i got reply from EBC and they just this site where you can clearly see those 296mm fronts on R34 GTT. I send them photos and "quotes" that 296mm are not for 34 GTT and they are too small. But it will be very hard to return them cuz nobody here knows 100% and they just copy those EBC catalogue :-D https://ebcbrakesdirect.com/automotive/nissan/skyline-r34
    • 04-LOOX
      R34 GTR Vspec Garage Sale - All must go!

      By 04-LOOX · Posted

      Hi, is the HKS  Tower Bar still available ? negotiable ? 🤔
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
×
×
  • Create New...