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FMIC Problems

PostPosted: Tue Sep 05, 2006 6:12 pm
by SeanGTS
The car pulls like a rapped date on WOT pulls. BUT, on the freeway when your just feathering the throttle to cruise at a normal rate, when you let off the car will studder and shake. Its at its worse in 4th and 5th gear, when you just build maybe 1psi of boost and let off, it will shutter badly.

Currently the car does not have the BOV installed. I have also boost leak tested for hours and it seems to be okay. Its hard to discern, but I may have a leak with the ISC valve below the throttle body, still not to sure :( The T Bolt clamps seem to be tight enough, and I do not believe they're leaking.

So is anyone on here running a decent size FMIC, and still retain factory like driving? I'm wondering if because its such a huge charge and volume of air in the system in comparison to the direct ATA intercooler, if the ECU gets confused with this? What do you think?

PostPosted: Tue Sep 05, 2006 8:42 pm
by turbo4wd
Hmm.. thats odd.. I had the same symptoms, but my stuttering after the FMIC was installed dealt directly with the BOV.. Since I set it up in recirculating, it hasnt given me trouble since..

PostPosted: Tue Sep 05, 2006 9:22 pm
by gearhead313
though i have a 165, mine has a slight shutter when you lift off the throttle. Its enough to bonk the rear diff bushing around, but not enough for me to worry about it right now.

I would venture to guess that since now the distance b/w the throttle body and the AFM is largely increase, that when you shut the throttle, it takes that extra second for the afm to close. thats my guess.

PostPosted: Tue Sep 05, 2006 10:57 pm
by 2RM
Would a BOV solve this Cause I think it would let the charge bleed out when you are off the throtle Put a bov and see what happens

PostPosted: Wed Sep 06, 2006 12:14 am
by Celi-GT4
Would you happen to be running a SAFC?

PostPosted: Wed Sep 06, 2006 3:51 am
by SeanGTS
No SAFC on this rig.

I tried getting the damn BOV installed today, but every welder I've talked to is so god damn lazy. Torquefreaks.com down the street wanted 120 bucks to weld on the damn flange with the pipe right in front of them (me providing all the parts!). I am now shopping for a TIG as my next mod.

I think the BOV is the issue as well, I just havent had time to install it on th new setup, hopefully my welder back home can take care of it on friday.

To describe it a bit more, 2500rpms on the freeway, 1/4 throttle, let off almost all the way to slow down, shutters. If i were to hold the throttle there, it feels like it could shutter all day!

I also had to mount my Mass Airflow sideways, think this has anything to do with it?

PostPosted: Wed Sep 06, 2006 10:11 pm
by RedCelicaTRD
SeanGTS wrote:I also had to mount my Mass Airflow sideways, think this has anything to do with it?


Id say that might be part of the problem. Even in stock form they cause a slight shudder.

PostPosted: Thu Sep 07, 2006 2:00 am
by gearhead313
Ya, i think taking care of the obvious is the first order of biz. Get the BOV in and flatten out the AFM. If neither fixes it, then we'll move on.

PostPosted: Thu Sep 07, 2006 2:43 am
by SeanGTS
Waiting on a mushroom style filter, then the MAF can be flattened, BOV should be mounted this friday.

PostPosted: Fri Sep 08, 2006 3:43 pm
by larsst185
I had exactelly the same problem after my fmic install.But the problem dissapeared when I adjusted the tps sensor.Try it!!

PostPosted: Fri Sep 08, 2006 7:01 pm
by Mafix
i ahd the same problem and it was the AFM...hence my vpc upgrade

PostPosted: Tue Sep 19, 2006 1:30 am
by donteatbugs
i have the same exact kit with the same exact problem. i will be getting my bov on this weekend hopefully, let me know what you find out. i dint think its a leak either but ive been wrong before. i put my top mount back on because i didnt like the shuttering. and finding someone with an aluminium welder is next to impossible in my town so i ordered the prewelded pipe off of ebay. im running a greddy type s bov for nowi have a k&n cone filter with the straight intake and had to cut a lot off the intake to fit it on. the guy also offers a tb adapter with the kit for 30 au with no extra shipping so my whole kit was like 680 us to alabama but no instructions and i had a badtime with the right side trying to figure out which pipe to put where. other than that it looks real nice. i would have pictures but i dont own a digital camera. but i do own an all trac so i guess i have the better end of the deal.

PostPosted: Tue Sep 19, 2006 2:09 am
by Simba
You have a much greater volume of air pressurized with that large core and all that piping. Guess where it all goes when you back out of the loud pedal.

Get a BOV on there ASAP. Assuming you don't have a boost leak or any kind of issue with the AFM (which doesn't care how much piping or how large a core you have), it wouldn't surprise me if you're stalling, or nearly stalling the turbo.

PostPosted: Tue Sep 19, 2006 3:38 am
by SeanGTS
BOV cured a lot of the problems, but I still have a slight hesitation (not to shabby at all) on the freeway.

Hopefully this weekend when I boost leak test it correctly (I'm a moron, dont ask) I will find the last of the leaks! Alright I will tell you, I'm a moron and was pressurizing the PCV valve instead of just putting a bolt in that hose. So I was happy I found my leak at first, alright, my spark plug wells are blasting air out, WTF?

So yeah, after trying to seal my valve cover 25PSI air tight, I realized that there really shouldnt be pressurized air in the crank case unless rings are letting a lot through.

PostPosted: Tue Sep 19, 2006 5:08 am
by donteatbugs
couldnt you seal off one end and just pressurize the piping? i dunno. someone tell me the best way to check for leaks because i might need to this weekend. i really wish this was easier