Installed BFI Stage 2 Chip, ran great for 4 days, now idle problems & rev hang

[GloryFreak]

I live about 2 hours from BFI in NC. I could drive up there on a Saturday or something if they needed a vehicle with the exact same symptoms we all are having to try and get this resolved.

[gtiswapped96]

^^kudos to u

[bluntman220]

if i wasnt 4400km away from my car i would mail my ECU to C2 as well.....the cars stored intill may .................but ill be home around x-mas if u need another to troubleshoot

lets get this fixed



zach

[bluntman220]

^^kudos to u

x2

[GloryFreak]

Just a quick question, has anyone changed the vacuum lines under their fenders? For the evap system on the left and the vacuum reservoir on the right? I haven't yet cause I haven't taken my fenders off yet. I have changed all other ones under the hood though.

[gtiswapped96]

u dont need to take off the fender just the splashguard under it...take the wheel off then the liner....i checked mine to0 and they were fine but give it a shot

[GloryFreak]

Will do, thanks man! .

[cm123]

hopefully should be getting a phone call from c2 today regarding the ecu/chip issue..
will let you guys know

[GloryFreak]

hopefully should be getting a phone call from c2 today regarding the ecu/chip issue..
will let you guys know

Can you ask them if they need a tester with the same symptoms? Don't know where c2 is located but I am close to bfi.

[cm123]

Can you ask them if they need a tester with the same symptoms? Don't know where c2 is located but I am close to bfi.

c2 is in Louisville Kentucky... they havent given me a call back yet

[cm123]

ok so I just got off the phone with chris from c2 motorsports. He told me that chip I had ran fine as well as the ecu. He actually helped me out and gave me a deal of swapping my chip with a brand new chip for $50 to see if it will work or not. I told him about this thread that we have going on about all our issues and said he's gonna take a look at it to see what other issues are going on with it. As fas as people willing to drive over to c2 to show them there car with the symptoms he said that would be great that way they can figure out exactly what the problem is.

once I get the ecu back from them I'll try it out and see what happens.
I will be keeping you guys posted on this

[cm123]

how many of us are having problems with a stage1 chip and how many of us are having problems with stage2?
that way they can get a better idea.. its on a 2liter regardless

my problem is with a stage1 chip

[GloryFreak]

how many of us are having problems with a stage1 chip and how many of us are having problems with stage2?
that way they can get a better idea.. its on a 2liter regardless

my problem is with a stage1 chip

Mine is with the stage 2

[Kiyokix]

how many of us are having problems with a stage1 chip and how many of us are having problems with stage2?
that way they can get a better idea.. its on a 2liter regardless

stage 1 here as well

Kei

[911_fan]

Other than the set idle speed, the differences between the two stages is very minimal.

[Kiyokix]

Other than the set idle speed, the differences between the two stages is very minimal.

There aren't any tweaks to help out with the different cams? If not, that's very very useful information for those of us with vagcom's...after I confirm my motor is good to go for a cam upgrade I wouldn't need a reflash to put a cam in.

That would be awesome if I didn't have to plan for shipping downtime at all?

Kei

[GloryFreak]

Fixed a small vacuum leak on my evap system. Also had the entire vacuum system "smoked" here at the automotive place where I work. No vacuum leaks found...And the car is still running rich and slight rev hang, lol. Also, ran the car for 4 days without the bfi chip and no cel, no rev hang and no richness codes found. Think there is something wrong with the chip?

[gtiswapped96]

Fixed a small vacuum leak on my evap system. Also had the entire vacuum system "smoked" here at the automotive place where I work. No vacuum leaks found...And the car is still running rich and slight rev hang, lol. Also, ran the car for 4 days without the bfi chip and no cel, no rev hang and no richness codes found. Think there is something wrong with the chip?

I dunno bout the chip dude...only person I can think of that has no problem with his is tdoggs his pulls pretty hard...also where did u find the leak in the evap system?

[Patrick007]

Okay here's an update and some additional information:

News From BFI

Just heard from Joe at BFI that a new chip is coming my way to test, so I'll post results once that swap is completed.

History Lesson / Smog Check

The whole reason I got into the BFI chip in the first place was because I couldn't pass CA Smog and suspected the GIAC chip was contributing to the problem. My first test result is below:



The car had audible knocking at the lower RPMs under load, so I was speculating that the timing curve wasn't right with the GIAC chip, and could have been causing excess combustion temps and thus excess NOx. Thus, I changed over to the BFI chip. That's when I started this whole rev-hang discussion. Since the first test, I installed the BFI chip, changed the oil, replaced the TB, cleaned the intake system, new fuel cap, and put the stock 3bar FPR back in. The second test results are as follows:



As you can see, it failed NOx again, with worse results. The front O2 sensor is <3 years old from GAP, so I don't suspect that. The cat is a TT high flow unit, PN 253160R, replaced July 2009. The biggest changed I've made since it last passed CA smog though was milling the cylinder head .040in, so perhaps that increase in combustion temperature is screwing me on the NOx. Now I don't have a wideband O2, but as I mentioned before, the plugs have always looked more white than tan, so I'm not ruling out that a lean condition is causing the high NOx.

Possible Causes of both Lean Condition/High NOx & Rev Hang?

This is still screaming vacuum leak to me. If the new BFI chip cures the rev hang (but the high NOx issue remains) then I could be convinced that they're not related. If the root cause here is a vacuum leak though, wouldn't that explain the rev hang as well as my high NOx (caused by lean condition)?

Best Test for Vacuum Leaks?

I've tried the carb spray, but there's gotta be a better test. Was someone else referring to a test where the intake is pressurized and backfilled with smoke to visually test for leaks? I haven't pulled out fender liners, etc searching for leaks, so I'm looking for some suggestions to perform an all inclusive test.

-Patrick

[Kiyokix]

Excellent information Patrick, I haven't had to take my car through inspection this year (not til next year thankfully).

I've been doing almost the exact same things as you (if not more ) in looking for this problem. Again this week I decided to go through again and replace every visible vacuum line I could see since I'd used some hose that wasn't originally meant for that exact purpose (worked great though). I bought a pack of hose, and went to town in th engine bay while waiting for my brakes to cool (replacing a rear wheel bearing).

After replacing all those lines including the long hose that leads down into the fender, I've still got nothing in the way of answers. I haven't bought more hose, and went under the car to remove the liner to replace whatever hose I see in there, but mad what a journey this has been.

Everything I've seen almost screams to me that it's a vacuum leak, but man I swear it's impossible for me to find one. I've sprayed carb cleaner, listened by ear, replaced lines, replaced gaskets, etc. etc. etc.

I almost hope that it IS something in the code that causes this...but then in my head it still wouldn't explain why I don't have the same power I had when I first installed the chip...my car is up to par with maintenence parts now, but wasn't fully up to par when I first installed it to test it. (the power left before replacing any parts so that's not it)

Still the only codes I get are the rich code (p0172) and the missing rear/secondary o2 sensor (p0141). I'd put another o2 sensor in there if I knew that would fix the problem, but that is the one that doesn't do anything other than check the catalyst efficiency...right? (one will be installed eventually, but not until I get a new high flow cat to put it in)
================================================== =============

On another note, I hooked up my laptop with the vagcom again the other night to look at the maf readings at various rpms (full throttle) as well as look at the lambda values.

The max reading my maf sensor gave me was


Coolant 99.0C
Rpm 6,040
Maf 99.86 g/s
Air temp 31.5C

Those numbers look okay to me, but I'm not 100% sure what the maf reading should be (roughly) at that rpm on a chipped/exhaust car. I think I remember tdogg saying something about it needing to be ~82% or near that mark of what the engine power would be. I don't remember if that's at the flywheel or drivewheels, and I can't find the thread/message he said it in lol.

A quick search on the net shows someone saying that ~HP= MAF reading/0.8

That would put my engine power at...

99.72 124.6hp @ 6,040rpm
97.22 121.5hp @ 5640rpm
91.53 114.4hp @ 5120rpm
84.03 105.0hp @ 4560rpm

I'd love to know what tdogg thinks of those numbers (tt exhaust, test pipe, and chip are the only power adders). The car still returns to me roughly 30mpg mixed city/hwy using my usual 92oct.

Looking at the vagcom numbers it showed that the car was running very rich at idle when I was finished driving, showing correction numbers of roughly -19% at times though it would never stay that high for a long time. When driving around the values are very close to zero.

Thoughts...anyone?

Kei

[Patrick007]

Still the only codes I get are the rich code (p0172) and the missing rear/secondary o2 sensor (p0141). I'd put another o2 sensor in there if I knew that would fix the problem, but that is the one that doesn't do anything other than check the catalyst efficiency...right? (one will be installed eventually, but not until I get a new high flow cat to put it in)
...
The car still returns to me roughly 30mpg mixed city/hwy using my usual 92oct.
...
Looking at the vagcom numbers it showed that the car was running very rich at idle when I was finished driving, showing correction numbers of roughly -19% at times though it would never stay that high for a long time. When driving around the values are very close to zero.

Kei

I thought the BFI chip deleted the secondary o2 sensor? Yes I believe that rear o2 sensor is only a metric for catalyst efficiency. I don't know if these computers change map or go into a form of limp mode when the CEL is tripped, but the best apples to apples comparisons would probably be to clear up whatever is setting the code (o2 sensor in your case). It seems I'm the only one not getting P0172 code (or any CEL) as well. If the norm is for the BFI chip to cause P0172 rich condition, and I'm not seeing that code, that further leads me to believe a lean condition is causing my high NOx.

causes of lean condition i haven't explored yet:

low fuel pressure: My injectors were recently cleaned, but I've never changed the fuel filter nor checked the fuel pressure, there's no sensor data to log for FP is there?

other sources of vacuum leaks: uhh

I get 23-25mpg, but i drive hard, always on 91oct in cali.

gonna log some data with VAGCOM soon and put that on display too.

[GloryFreak]

I had that rear o2 sensor code when I didn't have a rear o2 sensor bung install on my custom exhuast...Installed a bung and added the rear o2 sensor back, code went away so that has nothing to do with the richness code we are all getting with the bfi chip.

[Kiyokix]

I thought the BFI chip deleted the secondary o2 sensor?

causes of lean condition i haven't explored yet:

low fuel pressure: My injectors were recently cleaned, but I've never changed the fuel filter nor checked the fuel pressure, there's no sensor data to log for FP is there?

other sources of vacuum leaks: uhh

I get 23-25mpg, but i drive hard, always on 91oct in cali.

gonna log some data with VAGCOM soon and put that on display too.

Yea, the chips do delete the NEED for a rear o2 sensor, but apparently you must still have one plugged in on some cars. I remember some guys saying they never plugged one in, and never got a code, and others (like me) who don't have one plugged in that do get a code. The chip stops the catalyst below efficiency code from popping up though regardless of having a sensor or not.

I haven't bought a new one yet since I know that's not gonna fix my problem (except that code), so I'd rather hold onto the money just in case I find something that actually WILL fix the problem lol. (that and I really want a brand new high flow cat to put it in, not my test pipe).

If I were you I'd absolutely change that fuel filter out, it takes about 5 minutes to do, and it's pretty important. :p

As for fuel pressure, sadly there isn't any data in the vagcom that I know of that will tell you the pressures, but since you're doing some logging...care to let me know what numbers you get from your maf readins at a few rpm points? I know our cars aren't 100% the same, but I'm curious what kinda numbers others are getting.

Kei

[Kiyokix]

Okay so I installed the stock chip again today to do some vagcom logging, and then immediately swapped back to the chip to log again under the same weather conditions.

The only variables are the two different chips (stock vs. c2/bfi), and the intake temperature being slightly higher due to heat from sitting to change the chips.

Stock gave me a high of 100-102 g/s in maf data going from about 5300-6000rpm (don't have it in front of me). Intake temps were 28.5C (83.3F) at the time of the test.

C2 gave me a high of 99 g/s going from about 5800-6100rpm (again not in front of me). Intake temps were 31.5C (88.7F) at the time of the test.

If you look back to the data I listed the other night, the max was still the same today as was then with the chip installed. The other night the intake temp was down to 30C still yielding 99.72 g/s at 6000rpm.

What is boggling my mind is that while of course the throttle response is better, and the lower rpm acceleration seems better (not huge but still noticeable)...the stock setup is yielding higher numbers over a broader rpm band...on 93oct (which shouldn't really help the car gain power anyway).

For whatever reason it seems as though besides the throttle response, the car isn't making any extra power where it should be. This would confirm that I'm NOT crazy when I said that the car feels quicker/different than stock, BUT not nearly as quick as when I first installed the chip at H2Oi last year.

Since that time the only real mods I've done to the car are adding the TT exhaust, and the 42DD test pipe while I save up for a new cat. (mine was starting to rattle) Still the ONLY codes that come up are the p0141 (2nd o2 sensor) and the p0172 (rich), but as it's been cleared swapping chips the rich code hasn't returned yet.

When the throttle is pinned during these runs the lambda values are at 0.0%. While cruising the values are around 0 to say -3% at roughly 2200rpm cruise. Look again at around 1800rpm and you can be 0 to -8% or so...then at idle (set at 960rpm) you can be from 0 to -17% or so.

My thought right now is that maybe there is a leaky injector or something...but this is the 2nd set I've tried since I got a set from a fellow vortexer to see if my stock units were just not working out. Car is still the same as when I was using the stock ones. (didn't have a vagcom at that time). If I need to, I don't mind buying new units...but I don't want to buy parts that may not be causing the problem.

Okay thoughts...cuz my head hurts right now?

Kei

[gtiswapped96]

^^x2 on the car not pulling as hard as it used to when i first swapped in the chip

[911_fan]

O
Stock gave me a high of 100-102 g/s in maf data going from about 5300-6000rpm (don't have it in front of me). Intake temps were 28.5C (83.3F) at the time of the test.

C2 gave me a high of 99 g/s going from about 5800-6100rpm (again not in front of me). Intake temps were 31.5C (88.7F) at the time of the test.

If you look back to the data I listed the other night, the max was still the same today as was then with the chip installed. The other night the intake temp was down to 30C still yielding 99.72 g/s at 6000rpm.


Okay thoughts...

Just an FYI...your chip has nothing to do with A) your MAF output readings and B) controlling your throttle position.

The MAF converts temperature into voltage to deliver load readings to the ECU. It's just a sensor sending a voltage...not controlled by your chip. The ECU chip adapts to the voltage signal, not the other way around. Any differential in g/sec readings has to do with temperature, relative humidity, and barometric pressure. OR how you happened to drive the vehicle during the test procedure.

The throttle position is controlled by your foot. Not the chip.

Also, hot-swapping chips like this, and then doing logs back to back, is not going to yield an accurate comparison. It takes a complete ECU reset (disconnect battery and discharge) and about 7 cold starts for a chip to fully adapt....and thats taking into consideration your driving style during those learning periods.

[Kiyokix]

Just an FYI...your chip has nothing to do with A) your MAF output readings and B) controlling your throttle position.

The MAF converts temperature into voltage to deliver load readings to the ECU. It's just a sensor sending a voltage...not controlled by your chip. The ECU chip adapts to the voltage signal, not the other way around. Any differential in g/sec readings has to do with temperature, relative humidity, and barometric pressure. OR how you happened to drive the vehicle during the test procedure.

The throttle position is controlled by your foot. Not the chip.

Also, hot-swapping chips like this, and then doing logs back to back, is not going to yield an accurate comparison. It takes a complete ECU reset (disconnect battery and discharge) and about 7 cold starts for a chip to fully adapt....and thats taking into consideration your driving style during those learning periods.

Thanks for chiming in and clearing up that maf data for me. I know about the swapping (battery was disconnected though not allowed to sit for 30 mins) and ecu adaptation times. I just wanted to get some sort of data between the two, to see what was (if anything) different in output numbers overall.

Driving style wise is pretty easy for me as I'm a fanatical road racing type of guy...so consistency (especially in testing) is really big to me.

Not sure though what you're talking about with the throttle position though...did I say something that made it sound like I thought the chip controlled it? (or was that in reference to the lambda numbers or something else)

Kei

[Patrick007]

The throttle position is controlled by your foot. Not the chip.

.

I'm not sure what role the chip itself plays, but the computer most certainly plays a part in controlling the throttle position. When I let off the throttle, the ECU is commanding the idle control motor to keep the throttle open. It also opens the throttle to 'catch' the revs when you let off to change gear or come to a stop. In many of our cases, the ECU is over-shooting this return-to-idle aspect of controlling the throttle.

MAF data should consistent from chip to chip, as tdogg said it's just a hot wire anemometer, but yea I do need to log some data to show. I'll change the fuel filter too, I'm pretty sure I have one laying around just never actually changed it. My injectors were recently sent to RC engineering for cleaning and rebuild, so I'm not thinking I have injector problems.

Waiting for BFI's test chip to come in, then I'll clear everything and swap chips and report back. I'll take VAGCOM data prior to swapping chips so we can see some differences if necessary. What are the important channels to log? Again I'm a VAGCOM n00b, so where are you guys pulling those fueling percentages?

-Patrick

[cm123]

got the ecu along with the new chip back from c2 on friday but didnt get to open the package until tonight.
ill be swapping out the ecu tomorrow and let you know what happens. hopefully it fixes the problems

[Kiyokix]

Patrick, I usually look at channels 1, 3, and 4 when I'm logging my car (use measuring blocks not basic). Those have the coolant temp, intake temp, maf data, rpms, throttle position, timing, and lambda/fuel data.

I'm very interested to see what results you guys get with the new chips. If you don't mind, let me know what the throttle angle is (channel 3 I believe) at wide open throttle. Mine value is roughly 78, just want to make sure that's about what it should be.

Kei

[GloryFreak]

Updates?

[cm123]

Updates?

gonna be installing the ecu with the new c2 chip today, ill take a video to show how the car reacts..
hope this one works!

[911_fan]

FYI....its probably going to idle weird when you put the new ECU in. That is completely normal. The throttle body needs to adapt. Give the motor few cold starts before posting your results.

[cm123]

FYI....its probably going to idle weird when you put the new ECU in. That is completely normal. The throttle body needs to adapt. Give the motor few cold starts before posting your results.

thanks for the info tdogg..
im honestly just looking to see if the car is going to shut off or not after the warm up cycle. I just drove it now so i am going to wait for it to cool down a little before installing it

[gtiswapped96]

^^so excited right now...can't wait eekkkkkk