Jump to content
SAU Community

Does Mis-fire Actually Damage Anything?

illusiVe

By illusiVe,
in Engines & Forced Induction

 Share

Recommended Posts

illusiVe Proficient

illusiVe

Posted
Posted

my search came up with lots of topics on how to remove, but not if its bad for engine/turbo etc.

my R34 GTT is on 10psi with stock turbo, just recently under heavy acceleration it seems to missfire asif traction control is on (which it isnt) and i get lovely pop pop pop pop noise (while accelerating) towards redline, happens occasionally not consistantly..

could this be the R&R i've heard so much about? but why havent I had this issue before today?....

mad082 Grand Master

mad082

Posted
Posted

rich and retard isn't a popping sound. it is just a dead stop in power. it sounds like you have ignition issues, like a dud coil or spark plug. this isn't that bad as it isn't really doing anything except not sparking. it would actually be cooling the cylinder that isn't firing.

illusiVe Proficient

illusiVe

Posted
  • Author
Posted

i put boost to 11psi, doesnt happen anymore..

no farken idea.

it almost sounds like a rev limiter so it might pop every .3 seconds under the hard acceleration, then just stops.

power seems to die for the .3 seconds, or whatever, boost holds.

either way, problem gone for the moment.

chrissso Proficient

chrissso

Posted
Posted

Hmm, I'd go to the dyno and get your fuel ratios checked.

Popping is most commonly because its too rich. Rich mixture is harder to ignite. Then the mixture is burnt after it has exited the cylinder giving a pop. Usually caused by the air flow metre detecting too much airflow, (usually from intake mods like fmic and pod). The EUC adds not just a littlle more fuel, but a lot more. Too much infact as it thinks the excess flow is a problem.

I regard to the issue going away after the boot rise...

I can't say for r34's, but with 33gtst's, it would seem that the fuel pump only supplies enough fuel for std boost.

Your poping might have gone on higher boost because your fuel pressure might be dropping, and themixture is coming back to lean, or at least closer to where it should be.

Anyway, there are 101 answers to this.

IMO minor popping, as long as it is a minor misfire is not going to cause imidiate problems. However, if it is running rich, and you don't do something about it, then you risk other issues like cat damage and washing the bores.

Best best, get it checked on the dyno and then talk to the tuner about a course of action. Most probably ECU, maybe a fuel pump.

Chriso

psybic Proficient

psybic

Posted
Posted (edited)

Wow, I was JUST about to add about richness damaging the cat. Good point!

I have experienced an engine running way to rich and damaging the cat in a 3SGTE, which has the cat IN the DUMP PIPE! Stupid place I know, so more prone to getting damaged I guess... but yeah, amazing how much power you will be loosing if you are both running rich AND have a blocked cat.

I went from 62fwkws to 125 fwkws on that car with hi flow cat + retune.

Edited by psybic
Nozila Grand Master

Nozila

Posted
Posted
then you risk other issues like cat damage and washing the bores.

cat damage i undertstand, but 'washing' the bores? i didnt know this was possible. my understanding is that running rich only cause rediculous fuel consumption (blocked o2 sensor) and damaged/blocked cat.

RB20_ZED Collaborator

RB20_ZED

Posted
Posted
unburn fuel will damage the cat if it gets to much..

other wise miss shouldnt have any detrimental affects..

it will also use more fuel

is damaging the cat really that bad a thing? wont it just start to become a "high-flow" cat?

Rolls Grand Master

Rolls

Posted
Posted (edited)
i put boost to 11psi, doesnt happen anymore..

no farken idea.

it almost sounds like a rev limiter so it might pop every .3 seconds under the hard acceleration, then just stops.

power seems to die for the .3 seconds, or whatever, boost holds.

either way, problem gone for the moment.

Id say its a spark problem, weak coils possibly not causing a powerful enough spark. The higher boost level is blowing the spark out. Try gapping your plugs down (requires less energy for the spark) Also 11psi is as high as you want to boost the stock turbo. It wont last much longer above this level.

Its a very common problem, usually coil/sparkplug related. However it could be something else.

Read all about it here http://www.skylinesaustralia.com/forums/in...showtopic=32356

Edited by Rolls
RB20_ZED Collaborator

RB20_ZED

Posted
Posted
ahh, no...

it melts and causes a major restriction or blockage in the exhaust system, not what you want.

i guess ur assuming that when it melts u turn the car off and let it set... my guess is that the melted bits will be blown out the arse of the car.

RB30-POWER Mentor

RB30-POWER

Posted
Posted

what happens in reality, is the cat will usually break apart into pieces that are too large to go out the exhaust, but they block the outlet in the cat, (exhaust pressure pushes the loose bits to the outlet of the cat causing restriction) and your car doesn't make much boost/power due to the restriction and it can't melt further because the exhaust temps dont get high enough, because the vehicle isn't making any power.

the above has happened on almost all vehicles i have changed cats on, and they aren't all performance vehicles either.

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

    • djr81
      R32 update from 1990's spec.

      By djr81 · Posted

      New CAS just turned up from NZ Wiring. Looks like a nice bit of gear.  So, yeah. Triggered, bro. Realised I may as well do the cam belt while mucking about with it so will order one of them.
    • MBS206
      Duncan's V37.......race car?

      By MBS206 · Posted

      Even more fun, leave all the ADAS stuff plugged in, but in different locations, hopefully avoid any codes!   And honestly, all these new cars with their weird electronics. Pull all the electronics out Duncan, and just shove an aftermarket ECU and if needed a trans controller in, along with a PDM. Make it run basic but race car styled!
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      To follow up a question from earlier too since I had the front bar off again (fking!) This is what is between the bumper and the drivers side wheel And this is the navigator side, only one thing but its a biggy! So basically....no putting coolers in the wheel arches without a lot of moving other stuff. Assuming I move to properly race prepping this car I'll take that job on and see how the computers respond to removing a whole bunch of ADAS modules
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      So I prepped the car for another track day on Wednesday (will be interesting to see coolant temps post flushing out and the larger reservoir, with a forecast of 3-14 being 20o cooler than last time I took it out). Couple of things to mention; since I am just driving the car and not taking a support vehicle, I took the rear seats out and just loaded the back up Team Trackday style. Look at all that space! To cover off removing the rear seat....it is weird (note the hybrid is probably different because it wouldn't have folding rear seats) Basically, you remove the lower seat base, very similar to a r series but it is a clip that pulls forward to release the base rather than it being bolted down. Easy Then, you need to remove the side section of the rear seat on each side. There is a 14mm head nut at the bottom of the side piece, the it slides upwards off a hook at the top to release; you also need to unhook the seatbelt from the loop at the top. Then the centre piece is weird. You need to release/fold the seats forward with the tab in the boot on each side From there, there are 2,x12mm headed bolts holding the rear of each seat to the folding bracket, under the trim between the rear seat and the boot (4x christmas tree clips there, they suck). The seat is out but you can see where the bolts attach to the bracket
    • RP1421
      S15 Spec R

      By RP1421 · Posted

      As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
×
×
  • Create New...