legacycentral bbs

Hey guys, just wanted to know if anyone else with the revtronix stage 2 v.2 has figured out or found the issue that resulted in bouncy idle?? It's driving me crazy especially pisses me off when people are like yo your car is going to die soon. I tell most people i have aggressive cams but I shouldn't have to!!

Been gapping my plugs all over, from .40,.35,.30 back to .36. Same crap! Replaced maf, just today bought a new bosch o2. Still not satisfied with my idle. It's pretty quick i guess. yet it feels sometimes at partial throttle a bit sluggish othertimes it's pretty good.

Haven't found any intake leaks but you never know I guess?? I have replaced the manifold gaskets a few months ago, as well as the TB. Cleaned the TB, lots of cleaning crap.

Another thing is my fuel trims, right now seem to be fine about +5-8 throughout 1-7, yet the fricken idle is +14.8 which is maxed out.

Wondering if leaving the the snorkal box in affects the maf's reading. Another very good possibilities is the injectors are bad, or need to be cleaned.

Tomorrow, I plan on adjusting the IAC so it reads atleast 35% duty cycle currently 27-28% ish, possibly tackling removal of that damn snorkal and finding out if I can get my fuel system cleaned at a shop with those motovac things.

Some other suggestions would be appreciated!

Yeah I would try and get your IAC duty % in the 35% range. Either the ECU is a little bonkers and is not controlling it up high enough, or it's getting bad data back from the sensors which are telling it how/what to control the IAC at.

It's one of those scenarios where you try and fix the symptom, but not necessary the problem. However I think adjusting the IAC top to see if you can get in the 35% range would be a good diagnostic tool to see what happens.

version 3 of the Stage 2 chip fixed the issues you're experiencing. Specifically:

* Full throttle AFR can now be tuned up to +/-50% using REVScan and Select Monitor cable
* Increased fuel learning limits for varying injector flow rates, will solve bouncing/lean idle


I too had the bouncing idle problem with version 2. Seem to recall watching the short-term fuel trim keep getting lower and lower and then the ecu would reset it or something (details somewhere on the revtronix forum). another user (ScottyS?) had the fuel tables trim tables get maxed out (poor flowing lines or something), which is why the v3 has +/-50% on them now.

Thanks guys, did adjust my IAC to around 35% now and it seems better. Used a bit of wd40 down the hose, and again better still not perfect, now its sitting with the hose filled with wd40.

That's what I was worried about bsod and of course I can't get the damn chip reprogrammed ugh!!! It seemed to have gotten better now though after adjusting the iac and wd40 down the tube. Although still not perfect enough.

Debatting if I should get a 255 HP walbro? Currently running a stock wrx pump.

How do you adjust your IAC duty?

I have the same issue (stage 2, v.2). Helped some by changing the spark plugs, but I had some crappy old plugs in it to begin with.

I don't think the walbro will make a difference. I'm pretty sure it's a tuning issue. I also have a wrx pump in mine, from a 2006.

Curious, what turbo are you running with those cams?

You can adjust the IAC duty by turning the electro magnet top portion of the IAC valve. By doing this, it kind of fools the ECU, since the IAC valve is supposed to be calibrated at a certain spot. By adjusting the IAC valve you adjust that calibration point and can probably get a little more air in the engine to improve the poor idle due to the tuning issue.

This is exactly what I was talking about above where you're fixing a symptom, not the problem. It sometimes works ok, but isn't the correct fix.

Thanks Josh

Thats correct, this is a tuning issue. misadjusting the IAC to compensate is only a bandaid for the problem and can potentially cause other problems too.

Feels like a injector issue for some reason. Seafoam going in the tank soon will update if I come up with anything to help. Things I know for sure, is I have a exhaust leak before the turbo still need to order a bunch of seals.

Just a update. I added like 1/8 of a bottle of seafoam I found to 1/2 a tank of gas and today it was around 1/4 of a tank I noticed my idle was damn near perfect! Than I went to fill up and by the time I got home started going back to the way it was. I am thinking I should add a full bottle of seafoam maybe??

I think if my idle was better id be even more satisfied with the car as is atleast it gets very good fuel economy and meeting my performance needs.

Another update. Replaced 1/4 bottle of seafoam though many hoses including the IAC, 1/2+ of a bottle in the tank, air filter, cleaned maf, replaced plugs again regapped to .035 and I turned the idle screw 1 turn in. So far so good! Still need to leave the fuel trim maxed out. Well see how it idles at the end of the tank.

Another major reason I did all this was I have a emission test to pass and I have no converters so well see how it does

I have a hunch the ecu will 'learn around' your adjustments in a few days as it's an inherit flaw with the v2 chip.

I passed WA emissions (sniff test on the dyno) a few months ago with no cat + revtronix. There is a post somewhere on here regarding it.

over here since it is awd they just do a idle test question is do emission test with this tank that has seafoam or wait till next tank ?

Went out tonight car idled pretty consistant definitely not perfect but pretty good! Another thing I forgot to mention the boost control setup doesn't work well at all!! After I replaced the air filter keep hitting boost cut at partial throttle, and I find the boost control isn't very linear at all.

Now I do have a reducer in my lines thinking I should remove it. Or better yet ill just get a mbc but how reliable is a mbc if I have no boost guage? Or it won't matter since I have fuel cut and with the revtronix fuel cut hits instantly no delay.

I does take a some time ( or a day of getting partially on boost a LOT ) for the revtronix chip to have the boost controller relearn its settings. With a boost gauge, you'd notice it learning... overshooting the target boost, bouncing below it, then above, etc as you maintain the throttle. When I was previously having knocking issues and the ECU disabled the boost controller, I went back to the hallman MBC. Knock issues are fixed, but I haven't bothered to remove the MBC. *shrugs*.

Hmm your definitely right definitely better today. Works on and off I find still definitely not perfect yet pretty economical running 5ish psi at partial throttle

I have a vf39 restrictor pill in place. I ordered a wrx one to see if it makes a difference.

Another update found a pretty big leak at my uppipe to manifold gasket.

i have the R/T chip, I was told it's the newest upgrade. I have bad idle issues sometimes too, not always though. I know my IAC is messed up though, I could never get it to the desired range. I have changed it out a few times though, so it could be the wiring to the ECU.

What fuel pump are you running?

Exhaust leak fixed and bought the brass restrictor and now Boost control seems good, and response is perfect. Loving it!! Will update if I find anything to perfect idle.

Not sure what spark plugs you're using but I'ved tried the following:

Pulstar (New)
NGK V-Powers (New)

And my car hated them. It idled so bad it felt like it was about to die. At high revs it would stop accelerating it was missing so much.

I always had to put the old spark plugs back in (they came with the car and I have no idea how many miles are on them) but the idle changed to 98% perfect and it'd pull hard to redline.

These spark plugs are:

-NGK - BKR6EIX-11 (Iridium IX)

They are almost $8 a piece at sparkplugs.com but might be worth a try if you're still having idle problems.

I'm not to concerned about my idle anymore check picture/multi category ....