new FMIC GM MAF and TIAL, need help

[Atuca]

I am asking this on the DSMlink forums as well, but I am not totally convinced it is a tuning problems as much as maybe a tial problem.

I got my new ETS ultra short route FMIC installed and man, it looks perty, and I can't wait to start tuning that cooler air, but I think I am having a bit of a problem.

I got a Tial BOV and GM MAF and MAFT. I boost leak test and I fixed a few minor leaks, but I am good now, so.. why does my car act like it has a boost leak when I hit boost? Now I figure it was the tial BOV, because it was shipped with a 7 lbs spring, which, according to tial's website, is not enough, I need the 11 lbs. Everyone on dsmtuners said get a 7lbs spring, it is what DSM wants. But my BOV was open at idle, so I knew that is why my car wouldn't hit boost. I opened the BOV up and threw some washers in there and now it is closed during idle, and I am able to hit boost, kinda. The car still bucks around and I think the BOV may still be open, but I don't know (the car would be moving at that point :P)

So from my logs, can anyone tell me if that is indeed the problem? I am idleing at -20lbs so should I just buy the 11lbs spring from tial and all my problems will be gone? Or is there something in my MAFT i need to set, or tune in DSMlink? For now, long as I am not under boost, the car runs fine, so that is what makes me think it is not MAFT, but hey, you guys are the pros. I just don't like seeing my boost est at 26lbs, and my injectors at 120%. Something isn't right.

I wasn't sure if I needed to check a box to say "hey DSMlink, i has a new maf" but apparently I do. I figured because the MAFT always sent the same signal to ECU for those values, it still needed them to calculate air flow, but am I to assume when checking that box, DSMlink will just always have the values the MAFT usually sends to it just saved and ignore "new" values? I don't understand how telling the ECU to ignore the values would help much, other than free up the two ECU inputs for other sensors.

I am on stock injectors, so yes, they are having a little hissy fit with 40 lbs of air. After sleeping last night, if at idle my tial is closed now, when the car has boost, it should sitll be closed because whatever boost is pushing up on the valve, is equaly pushing back down on it form the intake manifold nipple I have hooked up to the top of the BOV. But EVEN IF the tial was leaking, the maf would calculate the air after the BOV, so shouldn't the car run just fine, even at 2lbs of boost or w/e?

I am really looking for two answers here, because I think it is a problem with the BOV. The car ran fine before this new setup, there are no boost leaks, so the only new "variables" are the BOV, and the MAF.

I'll go check that little box and see what happens, but is that going to lower my air flow readings by 20 lbs? Someone please explain.

and just BTW, i know of jeff's maf calculator, but I figure if I can't -36%, I need to just not boost for a while and go to the dsmlink boards :P

Alright just got back in from driving around the block. Now I tried to fix my fuel trims, and I am failing at it. I know .28 is the magic number at idle, and in order to achieve that I have to INCREASE the air flow 16%. That is going by the numbers from my LTFT Lo and STFT. It would make me believe I need to increase it by that amount, but why in the world would I need to? I have a dejon intake, that shouldn't make me need to increase airflow by 16% would it?

When cruising around it does the same thing. runs just fine cruising around, but soon as i get to the 0psi mark on my boost gauge and into boost, car starts stuttering and not moving smooth at all. Here are some logs to show what happens, and look at my fuel trims as I start to idle afterwards, they go haywire again.

I think I may need help doing the basics such as fuel trims

One last thing, and may be the problem of this all. I noticed I have a crack in my exhaust manifold, at idle I can feel hot air on my hand, on runner number 3 counting left to right. I don't think it is heavily affecting anything, beings my turbo was spoolin fine before, but would that have an effect on my fuel trims? If fuel trims are based at all off the front o2 sensor, that maybe I found my problem..

Let me know what you think!


Last bit of info is i tapped my j pipe for my MBC, and the tial has an un tampered with vac line from the intake manifold.
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There is what info I have thrown up over on the other forum, maybe you guys can help me figure it out before they do.

I am looking for a few answers.

What Tial spring should I have if my vac is at -20

if my tial BOV with the 7 lbs is closed at idle now i threw some washers in there, is it staying shut when i hit boost?

is the crack in my exhaust manifold ruining my fuel trims, affecting my o2 sensor (granted the car was working 100% ok before, just wacking fuel trims)

any other advice on how to make my car work again. it runs just fine when there is no boost, but won't go into boost unless i force it and it bucks like a mofo.

[turbosax2]

^You've got a lot written up there so I apologize if I missed reading something I question about.



Are you 100% positive you have the maft settings correct? The dials should all be zeroed except the injector one, which should be set for 450's. Of your two variables I don't believe this is an issue with the Tial, but rather just a tuning issue. You need to calibrate the gm maf first. The bov being open at idle is normal with a 7 psi spring. I feel that the 7 psi spring is the right one to go with.

When I'm looking at your log, first I press Ctrl-Z to clear everything from the graph. Then just check the boxes for GreddyBoost52 and BoostEst. Those 2 lines should be nearly identical at all points except above ~5500 rpms when the BoostEst will start dropping. Yours are nowhere close together. That is why you are supposedly flowing 40 lbs., and this is definitely not accurate for your turbo and boost level.

Let's start from the basics. Do another boost leak test to about 25 psi and post here how long it takes for pressure to drop. Can you verify fuel pressure? Check base timing using a timing light. (This shouldn't matter but it's good as a basic test just to check it out.) Make sure dsmlink is setup correctly for you (invert cas and ignore baro/iat). Now go and do your ltft tuning using this guide:
http://jeffgst.com/gmafcalibration2.html

Go in order - idle, rev, cruise. Resist the urge to go wot until you are confident you can handle the basics of ltft tuning. Report back with a log once you have done that.

[turbosax2]

Your o2 sensor isn't cycling like it should - possibly it's dead?

Also, take some time to go through your values and adjust the properties. I think changing your elevation in BoostEst / GreddyBoost52 is the only one that might apply to you.

[Atuca]

The DSMlink guys think that because of the exhaust leak I have in my exhaust manifold, it is messing up my fuel trims, which for the time being since this is my DD, I will fix it in a few weeks once I get my next paycheck (forced performance has one at $275)

That shouldn't make my car not run though right? I didn;t set anything on the GM maf, I just checked to ensure everythign was set to 0, that is what it should be right? is 450cc injectors not what it is set for from the MAFT factory? .... let me go check that again, because I didn't touch any dials. I figured since the car is idling just fine and running without boost just fine, the injectors would be fine, since i am on the stock 450s.

And are you sure about the 7 lbs spring? I know everyone says yes it is fine, but than why when after i put 2 washers in there, if i force into boost, it will kinda "blow off" but when there were no springs, it wouldn't "blow off". I assumed that havng the tial closed at idle would mean it stays closed into boost. I am not convinced this isn't a tial issue, but than again 40 lbs of air might make my car buck heh.

How would you set my airflow settings?

[turbosax2]

It depends on how big the exhaust leak is, but I don't know how it only affects the car now and not before the fmic install. I don't recall what settings the maft comes with from the factory but definitely check it out and make sure its set for 450's.

Regarding the Tial, my brother (snowborder714) has one with a 7 psi spring and it's been working great for us. The way the Tial works is boost forces it closed. The more boost you feed it, the harder it stays shut. When you lift off the throttle to shift, the bov sees vacuum and then opens. That is why we use the 7 psi spring - we want the bov to open as easily as possible and have no chance of surging during partial on/off throttle situations. I vaguely recall ludachris having surging problems through corners when he was on and off the gas with the 11 psi spring, then he switched to a 7 psi spring.


According to "airflow at 0.dat", I would set your 50hz slider at +29. Try it and see what happens, then post a log up.

[1992awdlaser]

The crack in the exhaust manifold will throw off the readings of the front 02 sensor and a wideband. This will cause your fuel trims to be unstable and wideband readings to be unstable. You need to fix this before you do anything else.

You need to figure out a way to get your coolant temps down or the ecu is going to be pulling timing which will make the car slower.

BUY INJECTORS immediately.

Your front 02 appears to be dead in the idle logs but when cruising it is operating. This is probably due to the lack of exhaust velocity at idle and too much getting out of the crack of the exhaust manifold. This is making the ecu think the car is lean so in return it is dumping fuel into the motor. This is why your fuel trims are maxed positive. So, fix the crack first and see if the o2 starts reading correctly at idle. If not, replace it.

What was your boost set at?

On the maft there are switches that you have to move to set it for 450's. You also have to set the maft for the size maf you are using. Here is a link to the manual. 1G / 2G DSM MAFT version 2.XX (Current Version!) - Full Throttle Speed Tech Support

[Atuca]

+29? Would going from a stock to FMIC set up increase my air flow by 29%? That would mean I would be feeding it more fuel right, which is the problem I am already having, isn't? My ecu thinks I have a crap load of air, wouldn't increasing that slider make it think there is even more air?

and if i take the washers out of the BOV and return it to 7 lbs, does that mean anytime i am just cruising around, I am not even sucking air through my air filter, but through the tial? Isn't that a BAD thing? I understand how they work, not sure how under boost it would close it because to me, if there is enough pressure to push it open, there is the same pressure from the intake manifold pushing it down through the nipple. Maybe I am completely not understanding, but meh, lets figure out why my car won't boost I am taking a final right now lol, let me finish this test and make a run around the school and i'll post back. but before I leave, can you tell me why upping air flow by 29% would make my car run better?

I understand the whole idle, rev, and cruise air flow settings, but +29% seems extreme to me, and seems counter productive. Last thing, my idle has my MAFraw at only 38hz, do i need to rev even the idle airflow setting to 50hrtx when setting that? or do i really just keep it at idle, even if it is at 38htz. and one LAST thing, i am not getting .28 airflow per rev things, i am at like .22 or w/e. Is that a problem?

[1992awdlaser]

Worry less about the g/rev and more about the fuel trims. You need to fix the exhaust problems and then post another log. The settings are going to change once the exhaust problems get fixed.

[Atuca]

MBC is set at 13-14lbs, but I havn't been able to get it to get into over a few pounds of boost without making my car buck like a bi@tch. The crack in the manifold actually would make sence that my fuel trims are outa wack, especially if the o2 sensor is how the ECU calculates that all.

SO everyone things the air flow needs to be adjusted to make my car work again? Anyone else Agree I need to +29% and adjust up like that on all my sliders? Airflow would not be affected by the exhaust leak, correct? I can run rich, long as I can drive faster than 25% throttle for the next two weeks.

[Atuca]

will jbweld fix an exhaust leak on my exhaust manifold? if i smother the crack with it? I havn't even seen this "crack" it is on the underside of my manifold. I guess it is inevitable I will have to remove it, will post up pics of the damage, but only if JB weld will fix the problem for the next few weeks. again, keep in mind this is my DD. (I really need a more reliable second DD I don't mod lol)

[turbosax2]

Originally Posted by Atuca

+29? Would going from a stock to FMIC set up increase my air flow by 29%? That would mean I would be feeding it more fuel right, which is the problem I am already having, isn't? My ecu thinks I have a crap load of air, wouldn't increasing that slider make it think there is even more air?

and if i take the washers out of the BOV and return it to 7 lbs, does that mean anytime i am just cruising around, I am not even sucking air through my air filter, but through the tial? Isn't that a BAD thing? I understand how they work, not sure how under boost it would close it because to me, if there is enough pressure to push it open, there is the same pressure from the intake manifold pushing it down through the nipple. Maybe I am completely not understanding, but meh, lets figure out why my car won't boost I am taking a final right now lol, let me finish this test and make a run around the school and i'll post back. but before I leave, can you tell me why upping air flow by 29% would make my car run better?

I understand the whole idle, rev, and cruise air flow settings, but +29% seems extreme to me, and seems counter productive. Last thing, my idle has my MAFraw at only 38hz, do i need to rev even the idle airflow setting to 50hrtx when setting that? or do i really just keep it at idle, even if it is at 38htz. and one LAST thing, i am not getting .28 airflow per rev things, i am at like .22 or w/e. Is that a problem?

Yes, +29. Read this again.

Step 1) Rev to 50Hz
Step 2) LTFT lo + STFT = Your 50Hz adjustment

Although you're only at 27hz at idle, from my experience the ltft lo and stft don't change that much between idle and revving to 50hz. Your ltft lo is 12.5 and your stft is 16.8.

16.8 + 12.5 = 29.3

Therefore, your 50hz slider should be moved to +29. Notice I said 50hz slider ONLY. To adjust the other sliders follow Jeff's page.

You're looking at this all wrong. The fmic and the bov isn't what is messing up your car (although I guess there is a chance the bov is messed up). The gm maf is NOT calibrated the same as your stock mas. You need to compensate for the gm maf by adjusting the airflow sliders. In a perfect scenario, a person with a stock mas would not have to adjust any of their airflow sliders to obtain perfect readings. The same does not hold true for people with gm maf's. They're just not calibrated the same.

At idle, your car does NOT think you have a lot of air. Hence why your AirFlowPerRev is low. By adding airflow at the 50hz slider your AirFlowPerRev should increase (at least that's my understanding of it).

By using a 7 psi spring you might be sucking in air through the bov cruising around. The only potential problem here is sucking in debris. The air that would be sucked in through the bov will still be metered since the maf is after the bov. There was a thread on this topic awhile back, try searching for it. I tried searching google for "how a tial bov works" but I couldn't find anything good. The bov will close whenever your intake pressure exceeds the spring limit. In your case, anytime your boost gauge is reading higher than 7 inHg, the bov will be closed.

I agree with 1992awdlaser - you need to fix known problems then go from there. No use trying to tune a car you know has issues.


I have attached a log for you to check out. This is snowborder714's car as we're currently tuning it. Press Ctrl-A to view all values, then Ctrl-Z to remove them from the graph, then click on the boxes at BoostEst and AEM5Bar. Notice how similar the two lines are (his 250hz slider needs some work). Now look at the airflow sliders and see how high his are.

[Atuca]

hey guys. im chilling out on the side of the road, trying to figure shit out.

for my curiosity, one last way for me to settle my curiosity and figure out if this was a bov problem or a maf issue, i plugged my stock maf back in and guess what?

my car boosted just fine, until i shifted and my car died :P lol @ ppl who vent without gm maf

so problem is definately not the bov, but the maf. so even as little sense as it makes to me, i set 50 htz at +29 than went to tune the 150hz. it wanted -26, and all i could muster was -20 through dsmlink. then tuned the 250, it wanted -24, so again i just set -20.

it is far from running well, but the car boosted a few lbs! i think if i fix my exhaust leak, i may be good.

[T9S1i]

get that maf dialed in and you will be a happy Link user!

[1992awdlaser]

Originally Posted by Atuca

hey guys. im chilling out on the side of the road, trying to figure shit out.

for my curiosity, one last way for me to settle my curiosity and figure out if this was a bov problem or a maf issue, i plugged my stock maf back in and guess what?

my car boosted just fine, until i shifted and my car died :P lol @ ppl who vent without gm maf

so problem is definately not the bov, but the maf. so even as little sense as it makes to me, i set 50 htz at +29 than went to tune the 150hz. it wanted -26, and all i could muster was -20 through dsmlink. then tuned the 250, it wanted -24, so again i just set -20.

it is far from running well, but the car boosted a few lbs! i think if i fix my exhaust leak, i may be good.

Did you set the switches on the translator for 450's and the size maf you have? Did you check ignore iat/baro in dsmlink?

[Atuca]

I didn't change anything on the maf, except insure everything said 0 and all the dip switches were at 0. first two dip switches at 0 = 3 inch maf. I have the 2g DSM MAFT so if I am reading the guide correctly, it is set at 450 from the factory, since you can't have smaller injectors in the car than stock (I'd assume).

I have clicked ignore IAT/Baro but again, if I am understanding things correctly, clicking that just frees up the inputs on the ECU, since the IAT and Baro that it is ignoring is the same numbers DSMlink stores in its memory when ignoring the values from the GM MAF.

Now, with my fuel trims kinda wacky, can I still tune for exhaust leak I am experiencing? Can I take air away using the maft and than use DSMlink to take more air and tune the car knowing I have a leak for now, til I get the new manifold? I have noticed my fuel consumption is a lot greater, using a 1/4 tank to drive ~40 miles.

[1992awdlaser]

Aux knob needs to be at 4
Base knob needs to be at 2

Fix that and see what happens.

[Atuca]

wow.. I see what you are saying, looking at the instructions again, I see that it is set at 430CC from the factory.. Besides the point, but, WHAT THAT FLACK IS THAT SHIT!!?!?

Let me go fix that and see what happens.

thanks for making me look like an idiot who can't read, I hate people like me.

Report results tonight.