i just installed an STS fmic, i love it, really feels more powerful(torqey!) seems like more power down lower rpms also, im still at 5.5-6#s boost, gotta get my boost control hooked up for 10#, but im getting lean codes on my last trip to town,po171/po174 , fuel sytem lean bank 1 and 2. why am i lean?, i upgraded fuel system (in my sig), i guess ill take care of it when i get my retune, this kit should come with the fmic, its awesome and also a high quality kit, nice welds on exchanger and all piping is hpc coated.

 

Nice! Post some pics when time.
Your lean conditions are due to the lower intake charge temps. This makes the incoming air "denser" or have more oxygen content, thus the lean(er) condition. BTW where is your MAF located relative to the IC? Before or after?
The better power down low is also due to the cooler air. The IAT sees lower temps and gives you more timing advance or less retard ( a good thing at lower RPM's ).
More driving should help the computer "learn" the mod else have Nelson send you another tune. Congrats!

 

dont beat on it anymore till you get that a/f fixed or you will wipe out a couple o pistons...

 

Congrats on getting the IC in there. The results sound good. Thanks for posting on the IC

Now get it tuned before you do some damage and especially before you add more boost.

Do you have a fuel pressure gauge? A good idea if not. From your post I assume you have a boost gauge , correct?

If you are going to 10# I would suggest you get some logging software if you are not getting some tuning software. You can do some expensive damage in a hurry if you are not careful and mail order tuning makes a lot of assumptions. That makes logging software an essential addition. There are too many horror stories around to ignore the potential for damaging pistons and other bottom end parts.

Congrats and good luck,

 

thanks for the replys guys, i do have a fuel psi gauge and have a interceptor scan gauge, i did some data logging today, no K.R. at w.o.t// o2 readings are b1=890/b2=900 at w.o.t./ long term fuel trims are 15.6 b1&b2@w.o.t. / I.A.Ts are 42degrees, ambient temp was 39degrees today. IGnition advance is 15.5 @w.o.t. /M.A.F.lb/m=32.7 @ w.o.t. ALL THIS DATA AND LOGGING IS NEW TO ME, AM i getting all the right info?, what do you guys reccomend i tell my tuner? i love the way the truck runs now. VERY STRONG, no hesitation and can do 1 hell of a burnout, but i want it safe as im some times get a po171/po174 fuel system lean codes as i come to a stop some times or at close to idle speed the codes will set. THANKS FOR THE HELP!- TIM

 

THANKSktmrider, my M.A.F is located after the cooler.hard to believe that the cooler made this big of a difference!i'd have bought it a lot sooner.

 

It looks to me like you are getting most of the right information. When I log I usually get RPM, Spark, IAT, Throttle Position, MAF, A/F Ratio, KR. I am running 10 PSI and I get spark of 12.8 at WOT which may be a little low but maybe gives a little safety margin. O2 readings are similar to yours and tend to drop to the 850 range by the end of a 1/4 mile run. My MAF sees 57.5 lb/min over 5080 rpm. I see a little KR once in a while but generally none at WOT. My A/F based on my stock O2 sensors drops from 14.7 to 11.7 with a little bump up to 12.1 at the end of a run. My IATs with no IC run about 40 over ambient and will rise 30* during a 14 second run at 10 PSI boost on a 50/50 meth/water mix (Winter WW). I usually don't monitor LTFT at WOT so I am not sure how they would compare to yours or if they are even meaningful at WOT. I love the way mine works too.

I would ask your tuner about the lean codes for sure. The codes could be caused by engine operation a long time before you are seeing a code set so I would not make any assumptions about the timing of the codes. Allen should be able to help you out with those codes. Have you replaced your in tank fuel pump? If not maybe you should consider replacing it with a stronger pump. Allen will be able to help you out with that as well. Definately sort that problem out before you up the boost any more and get a new tune for the IC and higher boost operation as well.

 

mass air systems compensate for colder air, that's part of their design. it sounds like you have a leak of air getting into the engine that the maf isn't seeing. you're going to want to check the tube sealing between the maf and the throttle body or any ports at the intake that may be causing a vacuum leak. it would still run strong anytime you're into power enrichment (about 40% throttle or more in a turbo application) because it's programmed to do so and the turbo will push air right past the maf anyway to richen it up if that's the case.

 

thanks for the help, ill get it figed out soon, called and talked to allen, and hes gonna give me a retune for the cooler, mort, i have a radix(walbro) fuel pump and 44# injectors, so the fuel system is up to par, zippy, good ideas, ill check tomorrow for intake / m a f leaks. where else can you get knowlegable help like this?! thanks -tim