Jump to content
SAU Community

Weird Misfiring At 2000rpm? (rb30)

BradyJ_R31

By BradyJ_R31,
in Engines & Forced Induction

 Share

Recommended Posts

BradyJ_R31 Apprentice

BradyJ_R31

Posted
Posted (edited)

Hey pplz.. I guess this is the fun part about owning a car i was sposed to be going for a roadworth cert. last friday but now shes playin up :D okay..saturday last weekend i put all new plugs in my R31, that afternoon it worked perfectly...(quieter..no smoke) then the next morning i started it up, it idled fine, let it warm up then lightly put my foot down and the revs dropped? to about 500Rpm and nearly stalled, then once it got past that stage and revved it to around 2000rpm it started unevenly revving (1500 - 2500)... so any help would be greatly appreciated, changing the plugs is all i have touched under the bonnet since it started playing up..i am trying to avoid a mechanic atm as they'll no doubt charge more than i paid for the car :)Brady.

post-29588-1150186036.jpg

Edited by BradyJ_R31
Link to comment
Share on other sites
SKY031 Grand Master

SKY031

Posted
Posted

Did you put the leads back on in the right order?

Have you re-checked that one of the leads hasn't come loose?

Did you buy the right plugs?

How did the old plugs look? (colour/condition)

Did you touch anything to do with the distributor?

You mentioned smoke prior to changing the plugs, what colour was the smoke?

Link to comment
Share on other sites
BradyJ_R31 Apprentice

BradyJ_R31

Posted
  • Author
Posted

Um the guy at supercheap auto picked out the plugs for me....they fit perfect and all but would surprise me if they are wrong, nah i checked all the leads and lead numbers, the old plugs had barely any soot on them but were very very old, i was going to try putting the old ones back on but i threw them all bar one : the smoke prior to the new plugs was like wispy blue smoke, evn after it had warmed up, i had a look in some other forums and some ppl said there AFM was gone....wats that lol...thnx brady

Link to comment
Share on other sites
Nosmo Enthusiast

Nosmo

Posted
Posted

Everyone seems to jump to the AFM (Air Flow Meter) conclusion, but its rarely the cause.

If your car ran fine before you changed the plugs then there is really no reason to look at things like the AFM.

Start by looking at the plug leads - are they clean and tight fitting. Are they in the correct order?

Look at any inlet piping removed during the replacement - are any hoses loose or missing (some are under the inlet / plenum and can be hard to see).

Look at the electrical connectors - are any loose or disconnected?

Hope this helps! If not, let us know and we'll give you some other pointers!

Cheers,

J

Link to comment
Share on other sites
BradyJ_R31 Apprentice

BradyJ_R31

Posted
  • Author
Posted

Ahh ok, because i did have to take all the inlet piping off above the rocker cover, i did not know about too many hoses under the plenum lol, so i might have to check it out, how much (average) would all new spark plug leads cost? could be a wise investment, the old ones could be the cause aswell as they arent the best lookin ones ive seen :D

Link to comment
Share on other sites
Nosmo Enthusiast

Nosmo

Posted
Posted

I have a set of standard leads on mine original from factory - still working perfectly.

Mate of mine had a set of after market 8mm leads on his GTS - ran like shit. Ended up putting my standard ones on the GTS...

Also, make sure your oil filler cap is tight and sealing properly. This will make a big difference if not right!

Link to comment
Share on other sites
BradyJ_R31 Apprentice

BradyJ_R31

Posted
  • Author
Posted

Geez i never realized how many things it could be lol but yeah this weekend i might just get in there and try it all out, maybe go back to supercheap and check the polug type, could it be anything fallin into a cylinder (dust,gunk) thats doing it? from when i took the plugs out,?..thanx a heap

Link to comment
Share on other sites
cry41t Contributor

cry41t

Posted
Posted (edited)

make sure you have the right gap in the spark plugs as well this makes a big difference.

For 33's its 0.8mm's off head. Dont know about yours but should be similar

Edited by cry41t
Link to comment
Share on other sites
BradyJ_R31 Apprentice

BradyJ_R31

Posted
  • Author
Posted

Yeah it sstill starts 1st time everytime, and it idles fine (around1000rpm) but if you slightly put your foot down the revs will drop....then pick up again and at round 2000 it just fluctuates the revs, but nah i havent checked the gaps yet, thnx brady

Link to comment
Share on other sites
rob82 Mentor

rob82

Posted
Posted
make sure you have the right gap in the spark plugs as well this makes a big difference.

For 33's its 8mm's off head. Dont know about yours but should be similar

8mm thats a big gap!!! I think he means 0.8mm. And for a naturally aspired RB30 it should be about 1.1mm gap. Check that you didn't crack a plug when you installed them would be my advice.

Link to comment
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

    • TurboTapin
      RB gearbox options

      By TurboTapin · Posted

      What makes you say CD009 boxes are not as strong as you would think? I've always been told the last revision (CD00A) is good for 1000whp and I have no issue's believing it when comparing one side by side with an RB25 box. Makes them look tiny. 
    • OO Dan OO
      Nismo 1.5 way Stub axle issue

      By OO Dan OO · Posted

      I picked up an open Center with shafts. I was told the Open shafts will fit a mechanical LSD and looking at them. I think they will work. Will update 
    • OO Dan OO
      Nismo 1.5 way Stub axle issue

      By OO Dan OO · Posted

      The manual says a lot about the different ratios requiring different shafts. all the Centers are the same but depending on the ratio, this determines the shafts because different ratios need the center to be offset more or less or right to left.
    • r32-25t
      Nismo 1.5 way Stub axle issue

      By r32-25t · Posted

      those 2 sets of shafts will not interchange and if you’re lucky you haven’t damaged anything with all your pressing and bashing you said you’ve done 
    • TurboTapin
      Lets play a game - What is causing my oil consumption?

      By TurboTapin · Posted

      Freshly built stroked RB25/28. Motor runs great but consumes a lot more oil then It should. This summer with the heat I was consuming roughly a quart per 1800-2000kms. Now with the cold weather coming in, I'm consuming a quart per 1000kms which is no bueno. I had originally chalked this out to break in taking a little longer then it should, but I'm now around 4000km's on this engine. I think it's fair to say something isn't quite right. Here's the kicker, can't find what's causing it. I've also spoken to my engine builder and Precision Turbo and can't figure it out. Here's my train of thought on possible causes and what I've done.  Precision Turbo - I originally started thinking my oil pressure might be a tad too high for my 6466 Gen2. I took the center cartridge out, and while yes there's signs of oil on the turbine heatshield, it's very moderate. There's also very minor in/out play that concerns me. I sent pictures and videos to precision and they said the residue and in/out play is minimal and they doubt this is the issue. For piece of mind, I went ahead and installed a Turbosmart OPR V2 to bring oil pressure down. Made no difference. Precision is willing to take it in on RMA for an inspection and I'll probably take them up on that offer for peace of mind. BTW. Is it just me or does the turbines inducer's look clipped and not even between each other? I just noticed this now while posting and looking at the picture zoomed in. Might just be the picture...  Rings - Hot compression test and leak down test look good. Compression is 160 +-2psi across the board. I leak down at 16% on cyl 1,2,3,5,6 and 18% on cyl4. Keep in mind I have a snap on leak down tester and they read high (I.E, 15% on my wifes 2018 Sentra with 70000kms). Sparkplugs show minimal oil (Only #4 seems to have a tad). At a quart per 1000km's though, I would be expecting them to be wet. Here's the kicker, I run WMI. I'm thinking what if my compression rings are great, but I have an oil control ring issue on cyl4 and my WMI is steam cleaning the pistons and sparkplugs? I can still see the "Spool" logo on top of my CP pistons. The only time I see smoke out of the exhaust is in the high rpm/load range. So far, this is my main culprit. I'll probably turn off my WMI and go out with the car at spring pressure tomorrow and repull the plugs. Other thing that's strange though is that I have never seen any oil in my catch can. Thing is still dry after 4000kms. Cyl1 - Left, Cyl6 - Right. Valve seals - They're new and I would expect oil consumption on idle, first cold start or during decel. None of which is happening.  Crankcase pressure - I have 2x 10an valve cover lines to a vented catch can. Head drain and opened up internal oil drain paths. I also don't run E85. I've never seen any oil in my catch can. Doubtful this is causing any issues.  Rear main seal - I have no visible leaks, but figured maybe it was my rear main seal. After now having added 2-3 quarts, I would expect oil to leak out the bottom drain channel and/or my clutch to be slipping.  Let me know your thoughts. With winter coming and taking the car off the road until spring, I'm fine with pulling the motor apart but I would hate to take it all apart and the turbo was the issue in the end.   
×
×
  • Create New...