gp1817

i have a 06 tc thats boosted......every time it pours out for hours......then i go to start the car...the afrs are fine,but when it starts to get to operating temp,the afrs lean out..then when driving car runs like poop and afrs all over the place..i had this problem once before,i did a quick ecu reset and everything went back to normal....only happens when its pours out side...im thinking the moisture is getting in some place...a leak or something,what could cause this issue...any ideas...

brett561tc

it's probably something to do with the maf sensor. Get a stand alone ecu and you won't have to worry about things like this. I know they're pricey but its money well spent.

gp1817

yea but what about the maf....explain please......how would a standalone fix this issue,if i only have this problem when it pours out,i have the aem fic which i dont like,but i have to worry about emission here,

That_Kid_Ju

If it only happens when it rains out, then moisture is getting into your lines somewhere. Look for boost leaks. Although if you had that bad of a leak, I would expect the AFR's to lean out all the time. Do you have the resistor mod for the FIC? May also be a bad MAF or leak through the MAF. Check it for cracks and bends (I bent mine from my 1st turbo install and gave crappy AFR's that bounced everywhere). After replacing my MAF, it was much nicer. Boost leaks will make the AFR's jump a bit. May also be tune related. I'd say to also check your fuel trims to see if the ECU is pulling too much fuel (then likely a tune or FIC-ECU related issue) or dumping a lot of fuel (likely a leak or tune issue).

gp1817

heres the thing....normal rain is fine..but lately,here in the north east...we been having hard down pours......and if i do a cold start,when its pouring out,hours after its started raining,afrs are normal for a few mins...then after it gets up to temp or start climbing to normal temp,i noticed the afrs at idle,climb to 15 then it tryes to get back but then go to 15.3-.5-16-16.5..i dont think it gets any leaner then that..i tryed to drive it hoping,ill fix it self,but car drove like crap,afrs all over the place...but i noticed after a do a quick ecu reset....everything is back to normal...its weird...yes i have the resistor mod to the fic...i never have any issues with afrs,only during really hard down pours...which like you mention,moisture is getting in some where...only think,that makes sense if the maf sensor..i can have my tuner look at my tune....but doubt its that,but,gotta check for leaks,maf,etc...

paul_dezod

What are your fuel trims when fully warm at idle? Then vs rain?

gp1817

good question lol.....let say,the fuel trims did change due to the rain...would it go back to normal,after a certain period of time driving,or like mention above,could be a leak some where,i wash the car,its fine,cause this is the second time it happen,i could get a car cover and cover the car up,it isnt my DD...but im just curious if theres a leak.....only thing that makes sense....ill have my tuner look at it...the next time,it does that,but im sure,if the tune looks fine,a leak would still cause the afr to go crazy esp when it pours out...

paul_dezod

Fuel trims change constantly. If they go real out of wack due to humidity, then there is only so much you can do with it. As Brett said, with a standalone, what you enter is what you get. So probs like this don't exist.

gp1817

interesting...i would love a standalone...i hate this fic....but my only problem is the emissions part,someone told me,on inspection day,just swap out the standalone and put the fic in,then vise versa afterwards...i dont know if thats true or if it can be done..im sure you can clarify this for me....

brett561tc

The maf sensor is very finicky. If it gets dirty or wet or whatever, it starts going all whacky. With a standalone ecu you can eliminate the maf sensor all together and tune off the map sensor, which in my opinion is a much better way to tune. I could have an intercooler pipe come off and still drive the car. You also have no st/lt fuel trims to worry about. It really is a must imho if you plan on boosting your car. As far as emissions go, that will be an issue as far as I know. I don't really have to worry about that as I live in Florida.

gp1817

ok,that makes sense,thanks for explaining it to me...i would love a standalone,but here in NY,theres emissions,so thats not a option,unless i knew someone,that could pass me,im gonna check the seal around the maf sensor,you would think,even if i reset the ecu it would still run lean if the maf was wet or something,,but a quick ecu reset..everything fine...i wrote down the afrs...its was in the mid 15's...like 15.5-15.7 then come up a bit..not to lean..