Jump to content
SAU Community

Recommended Posts

My stock standard rb25-det runs smoothly until after about 10 minutes it starts to lose revs & the car shudders randomly-but only while its ideling

it doesn't stall either but feels like its going to

i've been running it on BP ulitimate-added injector cleaning fluid to fuel & cleaned the airflow meter but no luck

has anyone else had a this problem before?

any advice will be appreciated

Link to comment
https://www.sau.com.au/forums/topic/252131-losing-revs-while-ideling/
Share on other sites

My stock standard rb25-det runs smoothly until after about 10 minutes it starts to lose revs & the car shudders randomly-but only while its ideling

it doesn't stall either but feels like its going to

i've been running it on BP ulitimate-added injector cleaning fluid to fuel & cleaned the airflow meter but no luck

has anyone else had a this problem before?

any advice will be appreciated

what RPM does the car normally idle at? because i know after about 10mins, the revs drop on my stag, im thinking its some sort of automatic warm up program.

does turning the Aircon on bump up the revs and make it idle smoother?

Edited by BIT SUS

As soon as its warm (around 10 ish or so minutes) in comes out of Cold start. this is where it revs higher to help it warm up and stop it from stalling ect.

Should idle with no accessories on at about 700rpm

so is it just missing on idle?

As soon as its warm (around 10 ish or so minutes) in comes out of Cold start. this is where it revs higher to help it warm up and stop it from stalling ect.

Should idle with no accessories on at about 700rpm

so is it just missing on idle?

it idles at about 1000rpm for about 10 mins then drops to 700rpm

runs smooth as above idle speed

my mechanic suggested it could be either a faulty airflow meter or

faulty/leaking vacuum hose/s [it could be 1 of a 100 different things unfortunately]

gonna to blast out the air-idel motor with carby cleaner asap & replace sparkplugs too

i did have a go at cleaning the AAC(Auxiliary Air Control)valve last week but didnt completely remove it so it wasnt done thoughly

thanks for the link[to removing it,etc]

ill give it another go

PS-carby cleaner smells good-kinda sweet :P

lol @ smell :D

heres an oddball:

- replace spark plugs but it'll cost ya, $20 NGK BCPRE6 .8m copper vgruve

- more carby cleaner, just for the smell

- hitemp Selleys 401 industrial strength silicone sealant; $15 incl corking gun from bunnings, and swathe a lather of silicone stinkyness ALL over your coilpacks.

- use carby cleaner a little more on the AFM just for old times sake

- drive for 10mins, check base idle, use base idle screw for slight positive adjustment

this ^^ should help, unless you have already done it, or are using Splitfires

mine idles at 400 ? nice and low. however, with the headwork it might be different..... waiting, waiting.

SO need my stag back !! :(

thanks to everyone for their help & advice

i've already sprayed the AFM with "mass air flow-sensor cleaner"

[got it from supacheap $20]

apparently u can use carby cleaner instead

ill get stuck into next weekend as the cars not being used atm

been drivin the neanderthol toyota work van during the week :)

Wow! My RB25 is doing the EXACT same thing! I'm going to try cleaning the AAC valve tomorrow and doing an idle adjustment. I'm also going to check the timing.

Please update if you figure out the problem!

Hi everyone. I drive a non turbo R34 Skyline with the RB25DE and its AUTO

I also have some idling issues.

When in parking, it idles around 900rpm but with my windows closed already but just using my switch to make them close the idle slowly drops to like 300-400rpm and feel like it wants to stall then it goes back up agian

Same with when i have the air con running and at stop at the red light with my foot on the brake, rev will be like 700rpm then drop alittle then goes back to normal again.

I changed to a new battery hoping it will solve it but it didn't.

I needed a new battery newaiz, it was like the original one since 1998. hahaha

Hi everyone. I drive a non turbo R34 Skyline with the RB25DE and its AUTO

I also have some idling issues.

When in parking, it idles around 900rpm but with my windows closed already but just using my switch to make them close the idle slowly drops to like 300-400rpm and feel like it wants to stall then it goes back up agian

Same with when i have the air con running and at stop at the red light with my foot on the brake, rev will be like 700rpm then drop alittle then goes back to normal again.

I changed to a new battery hoping it will solve it but it didn't.

I needed a new battery newaiz, it was like the original one since 1998. hahaha

Sounds like your issue could be the alternator...

  • 2 weeks later...

Problem solved-changed the sparkplugs :P

also thoughly cleaned out AAC valve on the same day but i think it was the old plugs causin the problem

two of em were lookin pretty haggard with a yellowish buildup of crap around em

now she's runnin smoothly again :)

Had I seen your thread earlier, I would have suggested the plugs. The crap that was fitted to my C34 for compliance (Autolites) made my car start & idle slow (occasionally stalling just after startup), and the idle would also sometimes drop off when slowing to a stop. I cleaned the AAC (which was spotless) without improvement. Changing the plugs to good-ol NGK (I spent up big & got the platinum - copper plugs weren't on the list where I bought them from at the time) fixed the problem 100% and it hasn't misbehaved in the 4 years since.

Had I seen your thread earlier, I would have suggested the plugs. The crap that was fitted to my C34 for compliance (Autolites) made my car start & idle slow (occasionally stalling just after startup), and the idle would also sometimes drop off when slowing to a stop. I cleaned the AAC (which was spotless) without improvement. Changing the plugs to good-ol NGK (I spent up big & got the platinum - copper plugs weren't on the list where I bought them from at the time) fixed the problem 100% and it hasn't misbehaved in the 4 years since.

That's pretty much what happens with mine. I'm using NGK bcpr6es-11 gapped down to .8mm What plugs are you using?

NGK Laser Platinum PFR5G-11

The only other thing I changed at the same time as fitting the new plugs was the O2 sensor - it was confirmed as being stuffed by the 12:1 idle mixture... That might be worth a look too.

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


  • Similar Content

  • Latest Posts

    • I much prefer that to an actual oil pressure issue, never would of thought it would of been a volt drop issue but SAU brains win again. Guess ill be turning down the oil pressure limit for the track and hunting some grounds. Ill hopefully update this thread with some high oil pressure and solid ecu voltage logs. 
    • You've just discovered a really good reason to tell yourself, yes, I do need to buy an aftermarket ECU. Put the MAF in the bin. Slap in the new ECU and have a think about what turbo sounds you prefer.  Do you want a 90's style BOV wooosh? Do you want a hektik tsututututu?  Mate, can't go wrong. Just gotta get that ECU and the world is your oyster. 
    • Hi. Iam just curisou about this topic. I saw this video. It is about Greddy Type FV2. I know that BoVs are about that sound but how and when to use it? I read some topic here and from what i have understand on stock RB with MAF there will be some "problems" if you use this BoV? It vents the air in to the atmosphere and the MAF on stock car needs this air back in to the intake and not out? Or is it wrong? If so...i saw you can put some adaptor to circule air back...but does that not "loose" that sound? I saw another BoV from Turbosmart and it has two "exhaust" like ports? One is for the stock tubing for letting air back and one is for "sound" and let the air in the atmosphere? Can someone please explain? This is the Greddy one:  And this is the Turbosmart.     THANK YOU!! EDIT: So i read about this topic some more and i if i understand that correctly: That Greddy can function either like BoV or 100% Bypass valve? And that Turbosmart is what they called hybrid so you can adjust what and how many air can be vented out or back in? Is this right? THX!
    • That dirty voltage drop is the culprit I suspect 
    • i cant get them all in 1 screenshot unfortunately as i just dont know how to move things around tbh, but they are all from the same log and the line crosses at the same point for all of them
×
×
  • Create New...