Any updates on this?

-E

 

I am fighting the same battle. Grrrr these darn big cams and MAF. Why can't we all just just along?

 

There are easier solutions that need to be tried before dicking around with idle stepper motor and MAF tables.

You need to:
1st — check for vacuum leaks (boost leak test)
2nd — install a softer spring DV
3rd — remove aftermarket intake tube and put the rubber piece back in (with whatever air filter you want)

Also MAF and most big cams work fine together. MAF and certain metal intake pipes don't, namely at low airflow speeds — i.e. low rpm idle.

 

Stock pipe is not an option for us guys with big turbos though

 

I have this problem as well. What intake pipes are you guys running. Currently im running the ETS intake hard pipe with the K&N Filter they provided.

 

OP is on the Green.
But even if you have to use a metal pipe, you have to check for vacuum leaks and try a softer DV if you have stalling/dropping rpm issues similar to OP's.

Metal pipes usually have different issues, the idle can be a bit erratic because of the airflow speed, usually this can be cured by upping the idle rpm to increase the airflow.. AFR's may swing back and forth, so rescaling the MAF for those pipes is usually necessary too.

But if you can use a rubber piece, i would definitely at least try that if you want smooth low rpm idle. My car idles at 875rpm with hks 280 cams and 1000 injectors at solid 14.7 afr, smooth as stock with the rubber piece.

 

I was thinking about swapping my Stock evo 9 DV to the APS Twin Vent to see if that will help.

 

i have the same issue as you guys lol still on stock turbo and just the basic mods.. im going to check my throttle cable and gasket as well .. 03's have been know to leak

 

So this may sound a bit weird but it was so worth it.......

I took out the MAF and cleand it. While doing so I noticed the top side has a blockage for the electronics to pass through. I thought to increase the laminar flow a bit why not flip it over and run it up side down. As it turns out it made a huge difference. The Hz does not fluctuate like it did on the normal way. I have the HKS scution pipe so the flow is much different than stock.

I also found a small phillips screw on the bottom of the MAF that was covered with silicon. I peeled out the silicon and backed out the plastic screw a bit to expose more flow area in the smaller bottom opening. This sounds a bit confusing, but it is there and you will see what I mean when you take a look.

So flip the MAF and open up the bottom screw and watch the great results.

I have Revolvers and they idle much better now that this was done.

 

Atleast it doesnt stall, mine does haha. Cant wait until I get the thing tuned.

 

i have exactly the same issue with my car. I have cosworth m2 cams with aftermarket cone intake, stock rubber pipe and stock injectors for now. no boost leaks.
I have the same 15.30 idle AFR and the idle goes lean when rpms go down. I am glad I am not the only one with this problem. I had an aftermarket (ralliart) intake pipe which made the car undriveable (surging and stalling) now it is MUCH better with the stock rubber pipe. I found that increasing idle rpm from the BISS screw (top of TB) solves the stalling issue and bring idle AFR closer to 14.7. i did this through the SAS mode of evoscan.
I will try a larger intake pipe (HKS) as I think this might make it better.

 

Before you spend the money on the HKS, try using the stock air box with a K&N filter. This has yielded great results with smaller turbos. Try cleaning the MAF and turning it upside down before you go either route.

 

My AFR's swing to over 20 when RPMs drop . The whole thing is really annoying.I cleaned the MAF and it didnt help much. Ive messed with ISCV values and stuff but that didnt help either. My tuner tried twice to fix it but no luck so far. I am running AEM intake due to it being legal. Im in CA. But I think I just gonna swap it to Perrin black foam filter(a little stealthier) with stock plastic pipe.
I will have to look into flipping the maf upside down, never heard about it before.

No vac leaks anywhere.

 

I have been working this issue. I have revolver cams, HKS suction pipe, stock MAF and K&N cone filter FIC 780s and the FP Green.

From logging the stall this is what is happening....

Initially when letting off the throttle AFR swings way lean. The ecu attemps to correct and goes way rich. Load is increasing as AFR is decreasing(getting richer) as RPM goes below base settings. With most ECU settings the timing numbers start to go negative at about 90 load 0 RPM and Fuel settings are starting to richen up a ton too.

I believe that with large cams, hard pipes and cone filters we need to tune the low RPMs. 1250 and below out to at least 120 load as if they were our base timeing and fuel settings.

I will be attempting this soon.

I also noted that stock ROMs 008 have the timing drop off like crazy in the 10 and 20 loads when compared to the 30+ loads.

With that being said we need to tune these areas to gain the best idle and non stall characteristics.

 

I actually had this same problem with my stock rubber intake instead of the funky S shaped Injen intake that came with their kit. I gained a small bit of power with the stock one (and also spiked extremely high compared to the Injen intake) but the idle was pissing me off so I went back to the Injen intake and it smoothed back out again. I lost power, but the idle is smooth. I'm replacing my entire Injen setup with a Nisei set, so I might have to try flipping the maf with either my home made intake pipe or the stock rubber one if I have this problem again.