Jump to content
SAU Community

Really Weird Problem...any Help?

heyhey!

By heyhey!,
in Engines & Forced Induction

 Share

Recommended Posts

heyhey! Rising Star

heyhey!

Posted
Posted

ive been around skylines for years...but this one was a little weird

r33 rb25det

SOUNDS like its running on 5 cylinders on idle

SOUNDS like its running on 5 cylinders when you go to take off and let the clutch out

at about 1500rpm BAM dissapears!!! and runs PEFECTLY

can run as much boost as you want ...rev to any limit or do anything you want

its like under 1000rpm to 1500rpm it sounds like its running on 5???

o2 sensor?

Link to comment
https://www.sau.com.au/forums/topic/265870-really-weird-problemany-help/
Share on other sites
blind_elk Grand Master

blind_elk

Posted
Posted

See what you've done, God! I warned you this would happen when you invented the O2 sensor - now the O2 sensor is the cause of every single problem in the modern EFI engine!

heyhey! - have you bothered to analyse which - if any - cylinder is misbehaving at low rpms? Have you checked that the VVT solenoid is working?

heyhey! Rising Star

heyhey!

Posted
  • Author
Posted (edited)

it used to run fine...but just sort of happened

i thought if it were plugs or coils...wouldnt it be doing it all the time?

BLIND ELK---- havnt found which cylinder...as it only runs on 5 when letting the clutch out... that tiny moment of initial take off

havnt checked the vvt solinoid will do that today

Edited by heyhey!
heyhey! Rising Star

heyhey!

Posted
  • Author
Posted (edited)
well until you workout which cyclinder is missing - no-one can help

Even then, once you FIX the once that is causing the problem, you'll find you dont have one anymore...

if i knew which cylinder was playing up IF ANY do u think id be posting here asking for anyones help???

i ask the question incase anyone else had been througha similar problem....

or for help from people that had ideas... not useless comments

as i said above....it SOUNDS like its running on 5 cylinders very breifly on take off...very very breifly though ( it may not even be running on 5 but sounds that way)

then runs unbelievably well for the rest of it

constructive ideas or people that have had a similar problem would be a great help

3lit3 32 ill look into this

.

Edited by heyhey!
R31Nismoid Grand Master

R31Nismoid

Posted
Posted
if i knew which cylinder was playing up IF ANY do u think id be posting here asking for anyones help???

i ask the question incase anyone else had been througha similar problem....

Well how about you go and find out? Like i said...

heyhey! Rising Star

heyhey!

Posted
  • Author
Posted
Well how about you go and find out? Like i said...

your amazing...i went out and found it was cylinder 1....and now just like you said...its FIXED!!!... i didnt even have to touch anything!

NOT

what im getitng at if it is cylinder 1 ,2 ,3,4,5,6, what difference does it make if i have no idea what causing the problems

HENCE why i ask for opinions on THE problem...not which cylinder it is

for example ...oh that sound like an injector sticking problem i had in my old r32

example 2 ...oh that sounds like a dirty 02 sensor problem i had in my silvia

etc

Punk72 Community Regular

Punk72

Posted
Posted
well until you workout which cyclinder is missing - no-one can help

Even then, once you FIX the once that is causing the problem, you'll find you dont have one anymore...

Yeah you need to chill out a bit!!, hey hey!? is having a bit of trouble and is simply asking around for some advice and isn't that what this forum

is for!! yes maybe it is hard to give advise to hey hey, as there could be a number of reason for what it is doing but maybe some where to start would help instead of being a smart ass

nIsMo86 Experienced

nIsMo86

Posted
Posted

+2 I'm with Punk72...

R31Nismoid, You usually have contructive ideas...bad day? :blink:

In regards to the problem, i'd suggest check your plugs first as it sounds like they may be fouling on idle then cleaning themselves as the revs go up. Also you may have the wrong heatrange...what plugs you using?

BensDR30 Experienced

BensDR30

Posted
Posted

We can suggest generic solutions all day, but knowing which cylinder is important.

See if you can get access to someone with DataScan or equivalent & do a software-based power balance test at idle.

It may just be a dud plug, but do you really want to pull them all out, change them and still be wondering what the problem was?

Where are you located?

The Dan Grand Master

The Dan

Posted
Posted

Hey let's not beat up on Nismoid here.

It is extremely important to know what cylinder a missfire is on. You simply cannot diagnose a missfire unless you know this.

It's a very valid statement to make as we are all here offering advice for days and days, using our own time, and after 5 days of rigorous testing you turn around and say 'oh I found the problem fellas, it was missfiring on cylinder one because there was a slightly broken wire in the injector plug at the terminal'

FUUUUUUUCK!!! - is what everyone says

If you are talking about some kind of shudder when you take off, could it be something silly like clutch shudder?

Also, if you have a valve seating problem, it will only be present at idle and the beginning of throttle (if the leak is tiny) but the missfire will definitely be there at idle.

Is it there from idle all the way up to 1000rpm? or is it fine at idle and just there once you try to take off?

heyhey! Rising Star

heyhey!

Posted
  • Author
Posted

see everyone is split

im saying if i knew which cylinder it is i wouldnt be posting ...i would have found the problem and fixed it the second it happened

you guys are saying find the cylinder and then u'll find the problem

im saying...ok its cylinder one! to solve this issue

now what would cause a car to miss under 1000rpm on cylinder one.....any ideas?

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

    • PranK
      My BMW E39 528i touring

      By PranK · Posted

      Oh, forgot to add, A few months ago I was getting mixture codes and the car was using crap loads of fuel. You could smell the unburned fuel in the exhaust, it was crazy strong. Economy was over 17.5 l/100 and usually around 19. I smoked the engine and found a leaky CCV hose which I replaced and then I replaced my two pre cat O2 sensors, I also replaced the MAF. This fixed my mixture codes and improved my exonomy but I'm still 14 - 15 l/100 when pottering about town so something is still amiss. Throttle response is much better and it has more pep but I'd like to know why it's still so thirsty (and I'm hoping that whatever it is gives me a bit more poke).    
    • 25zenki
      S1 rb25/s14 starting problem

      By 25zenki · Posted

      Car is on factory injectors/z32 maf/ q45 throttle body/ z32 ecu with nistune 
    • 25zenki
      S1 rb25/s14 starting problem

      By 25zenki · Posted

      Hello all, currently finishing up a rb25 swap into my s14. Having issues with starting, car has spark (confirmed by pulling a plug and watching it spark), has fuel(confirmed by checking pulse/voltage at injectors all spark plugs are soaked in fuel). Car cranks over and pops into the exhaust with a heavy fuel smell but no attempt to start or run, I have torn the timing cover off and triple confirmed timing, turned the CAS in multiple spots both directions, attempted to start with coolant temp and maf unplugged, checked my fuel lines and made sure they weren’t backwards, checked voltage at cas/injectors/coilpacks, made sure all the grounds in the harness are connected and added a few grounding straps (1 from chassis to block, 1 from chassis to head, and 1 from chassis to igniter chip) I am getting stumped here. As a last ditch effort I made a full grounding harness tonight that’s going to run from the battery and add an extra ground from the battery onto the coil pack harness/igniter chip/ intake manifold/ Wiring specialties harness ground/ and alternator. I’m hoping maybe the grounding harness will fix it here but posting here to see if anyone has any other ideas on what else I can check. My fuel pressure is unknown right gauge will be here tomorrow.  IMG_3206.mov
    • CRSKmD
      R32 Sedan - Grip and Drift (have my cake and eat it too build)

      By CRSKmD · Posted

      yeah I was shocked when I checked my spare OEM on and as below that's how they come from Nissan. (side interesting note new NEO gearbox and replacement park lack the brass bush on the tips and its just all alloy) unsure about damage to the box currently back at 1110 to be pulled down/inspected and selector fork replaced as he built it previously and given the never before seen failure on his billet forks he is replacing it under warranty. He said he has used always OEM the keyway tab without issue for years so it could be an unlucky coincidence. I did talk to him about the sharp corners and stress concentration too. Re: hard shifts i got 7+ years out of the OEM one and the fork itself failed not the keyway. so could be bad luck as I said or an age thing + heat cycles in box and during fabrication of billet?
    • MBS206
      R32 Sedan - Grip and Drift (have my cake and eat it too build)

      By MBS206 · Posted

      That's some really horrible design with the way it's cut/shaped! Is there much damage to the box that failed in? IE, new fork and you can go again, or is it a total rebuild again? Id be trying to build that piece from scratch, and getting some reliefs added in the corner to hopefully stop breakage, and then swapping boxes ASAP, and then doing the same to the currently good working box. I'm assuming hard shifts have not been friendly to it!
×
×
  • Create New...