Jump to content
SAU Community

Recommended Posts

Hey Guys

I recently installed a HKS mushroom filter on my S1 R33 (Auto) and noticed that the idle is running rough. Sounds almost like its missing a bit and revs at idle range from 400-900. The power on low end (10-40km) is really shite as well, feels really laggy. This is the only mod i've done to the car, everything else is bone stock.

The air filter was put on after a mate tried to get more sound out of the stock BOV. I.e. Plugged the plumb back hose and vented the BOV to atmosphere. We found that the car ran rough as guts, hunting at idle and stalling, but sounded great hahaha, so we put the BOV back to stock plumb back and just bolted on a mushroom filter. Later did some research and heard that stock BOV is always open just a little and idle was hunting due to lack of back pressure. Is this true?

My assumption is that the problem will be fixed after installing an after market BOV which stays closed when not venting. Will this fix the problem? Also I haven't reset the ECU after changing to mushroom filter, maybe give that a go????

Cheers

Link to comment
https://www.sau.com.au/forums/topic/163542-rough-idle-after-pod-install/
Share on other sites

How do you clean your afm?? Carby cleaner yeah but like do i open it up and spray in there? I would have thought this problem had more to do with air pressure?? Wouldn't know SFA though so any suggestions are welcome. Thanks for the replys so far guys

an aftermarket bov won't allow you to have it atmospheric because vacuum will still be strong enough to open it under normal driving conditions unless you tighten the bov more but then there is no point having a bov if it's too tight to properly vent pressure and cause flutter.

when your car is using an AFM its best to keep the bov plumbed back to the intake even if it's aftermarket because you're letting air that the AFM has sensed and added fuel for out of the system causing richness.

to put it simply every time you hear the bov vent you would be wasting fuel and your car would not run well.

Air Flow Meter!!! NOT Air Pressure Gauge..........

Who said Air Pressure Guage?? Can't find it anywhere on the page....

So Dobz..Are you saying that i can't have an atmospheric BOV??? How do other skyline owners do it? Plus i thought you have to have some sort of AFM all the time??? Confused.....

you can have an atmo BOV , you just need a good one which has a good spring and vents well . yes a lot of people have idle troubles because of them if not setup properly . try adjusting the bov , and watch your idle change . a cheap bov will cause numerous amounts of trouble because they arent made well - hopefully you have a decent one , for your own benifit.

here are some things to do :

ACC Valve : search ! . you will find a very well written DIY to clean everything out . your idle will run much better . you need carby cleaner for this - its a must !

AFM: clean it with carby cleaner aswell , spray it in the direction of the arrow on the AFM. there could be some debree attatched to it .

both of these will definitly help your idle if not fix it . remember to search before you post.

its most probably due to the bov not being plumbed back as the ecu is expecting that extra air being recirculated, i did the same of my gtst and it ran like crap plumbed it back and it was all good and because i had a pod put on you could still hear the bov pretty loud if thats what ur after. However i seen ppl not run plumb back systems and they ran fine, you can get a extra module to control ur idle etc, ive also seen ppl run two bovs, the original plumbed back and another one to the atmosphere which works too i guess.

The BOV is still plumbed back, changed that back to stock before adding the pod. I noticed last night that it behaves much better at night when the air is cooler than in the day, might sound stupid but it seemed heaps quicker than when stock. It's just in the day time that its really laggy from 0-40km/h.

Maybe the super special microchip in the pod is dirty. Try cleaning it and it will not only run better but give you 20 or 30more rwkw's . :laughing-smiley-014:

but in all seriousnes just try disconnecting the air flow meter and putting it back in again, also reset the ecu before starting car again. I ave had identical problem twice after mucking around with the pod filter and thats what fixed it for me..

good luck

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 will rebutt this and the preceding point from Dose....but without doing any calcs to demonstrate anything and without knowing that I am right or wrong. But... The flow capacity of a fluid transfer system is not limited by the smallest orifice or section of conduit in that system, unless it is drastically smaller than the rest of the system. OK, I use the word drastically perhaps with too much emphasis, but let's drill down on what I really mean. The flow capacity of the system is the result of the sum of the restrictions of the entire system. So, to make an extreme example, if you have a network with 3" pipe everywhere (and let's say a total length of only a few metres) and that 12mm ID restriction of the oil filter connection being the obvious restriction, then for any given amount of pressure available, the vast majority of all the pressure drop in the system is going to occur in the 12mm restriction. But.... increase the length of the 3" pipeline to, say 1000m, and suddenly the pipe pressure loss will likely add up to either be in the same order of magnitude, possibly even exceeding that of the 12mm restriction. Now the 12mm restriction starts to matter less. Translate this to the actual engine, actual oil cooler hose sizing, etc etc, and perhaps: The pressure loss caused by flowing through the narrow section (being the 12mm oil filter port, and perhaps any internal engine oil flow pathways associated with it) is a certain number. The pressure loss through, say, -12 hoses out to the cooler and back is negligible, but The pressure loss through -10 hoses out to the cooler, at the exact same length as the above, starts to become a decent fraction of the loss through the 12mm stuff at the filter port. Maybe even it starts to exceed it. I could actually do these calcs if I knew 1) how much oil was actually flowing in the line, 2) gave enough of a f**k to do things that I hate doing for work, voluntarily for a hypothetical discussion. Anyway - I reiterate. It's not the narrowest port that necessarily determines how much it can all flow. It is the sum. A long enough length of seemingly fat enough pipe can still cause more loss than a semmingly dominant small bore restriction.
    • To pick up what Dose is putting down. Not a lot of point running a huge hose if the motor is still restricted to the smaller size... It's only capable of flowing so much at that point...   *Waits for GTSBoy to come in and bring in the technicalities of length of pipe, and additional restriction from wall friction etc etc*
    • Hooley Dooley these things have some history! If i sell them they will need a certificate of providence to prove they have been in the hands of verified RB20 royalty! They have been stored in a plastic tub, away from sunlight and moisture. They are in mint condition. And they will stay that way, as i have sprung the money for a set of shockworks coilovers. I'm just working on getting them in at the moment, after rebushing the rear of the car, and while the subframe was out i welded in the GKtech reinforcement bracing as well.  They will get a workout at Ararat King of The Hill in November. I ran 48s on the short course there a few months ago, and i am hoping with new bushes and shocks in the rear i can launch a bit harder. There was a fair bit of axle tramp when i tried too hard off the line. a few of the corners had dips mid way which also made the car feel a bit unsettled, hopefully this will help there too.   
    • Food for thought, the stock oil filter thread is a 3/4-16 UNF, which has an ID of about 10 to 12mm (according to ChatGPT lol). Now compare than to an 10AN, which has an ID of about 14mm (Raceworks is 14.2mm, Speed flow is 14.27mm).  
    • Yep, totally get that. However hooking in for Generator back up is only a few hundred bucks for the wiring. You could put a couple of those in (for different circuits explicitly) and run a couple of baby generators. Bonus, you can balance them across different circuits, and now have backups in your backup. I'm looking at buying places that won't even have water etc, and I don't mind the idea of getting off the electric grid either, even with everything you've said. This country already has enough power outages that even the mains grid isn't that reliable anymore. I do agree though on spending a bit more to get better gear, and to add some extra redundancy in to the system too.
×
×
  • Create New...