Setting up GM maft on my car/ need a little help

[44pirate]

I run the non turbo FPR which raises 1:1 and gives a base fuel pressure of 47.6psi
thus requiring larger injcetor compensation for the added flow.
Most setups ive researched when they have 255lphs and stock regulators, they overrun to about 48psi... If my theory is correct that means my car should have less overrun since my base fuel pressure starts at about what most cars over run to, not that im not doubting there isnt any overrun, im sure there is, maybe just as bad.
Some may disagree, but Ihavent found any information otherwise that would suggest my theory is wrong.

That particular FPR is regulated to the fuel pump output. If your running a 255pump then you have to adjust it to the propper fuel pressue. Unless the particular FPR your using is for a 255 to regulate the output to 47psi. I don't think a stock non turbo fuel pump is anywhere near 255, I could be wrong. That stock FPR is regulating that particular fuel pump output to 47psi.

 

[tunethis]

Ok i will try that tommorow. I need to do something because I do way too much driving to and from work to be wasting gas .

Tune will be off w/ a boost leak before or after maft? I thought one of the main reasons switching to blow thru setup is to not have boost leaks affect you before maft since it reads air after 90% of the rat maze of intercooler pipings.

But, I do have a little annoying leak at my tb shaft seals which is after maft....
Will need to fix that soon, and also fix my boost leak at the forge bov ( w/ another valve)
because it doesnt seat right and lifts up and looses pressure at anything over 20psi.
Other than that I dont have much problems w/ boost leaks.

Your fuel trims dont seem too far from mines, wish you had a wideband to know what exact afr that is for your trims.

Theres still a lot of power left in my setup, I see 19degs of timing at 7k with 24psi falling to 21 by redline right now ( on a chip set 11.3 afr which im sure is really richer than that)
and the car pulls good w/ this maft setup over the 2g mas and I logged like 1 count of knock on my pulls.... Im satisfied w/ my boost/timing on 93 octane but i think im going to just keep leaning everytihng out until I see some concernable knock, then richen it back up to the peak point before the knock.... Think thats the best way to go without a W.B.O.

I blew off a coupler on the GM maf (the one before the maf) and the car ran fine but when I stopped, it stalled. It's not suppose to I thought but, the car would not keep a steady idle at all. I also have a small boost leak at the shaft seals. I tried to fix them but I had problems during the install. I have a 90 tb and I had the proper seals and all. For whatever reason, it still leaks a little. I am going to buy a newer tb complete with all new seals. I will also get a aeromotive fuel pressure regulator to lower my fuel pressure to the correct level. A wideband will come after those things. After all that, I should be able to get a really good tune with the maft until I get DSMlink.

 

[Black_Bullet]

That particular FPR is regulated to the fuel pump output. If your running a 255pump then you have to adjust it to the propper fuel pressue. Unless the particular FPR your using is for a 255 to regulate the output to 47psi. I don't think a stock non turbo fuel pump is anywhere near 255, I could be wrong. That stock FPR is regulating that particular fuel pump output to 47psi.

Then why havent I been running lean at WOT all this time.
It rises 1:1 with boost, it just starts at roughly 48 psi, so thats factored in with my injectors flow rate. Maybe I am misunderstanding what you are saying?


Anyways, i fixed another small boost leak I found, and I noticed my o2 started cycling a little bit longer than it had been before when I first installed the maf.
Its still not cycling as much as it did when it was on the 2g mas , it only cycles till like 3500 rpm now*( I have extended closed loop in chip.)

Im not really worried about that, i am getting some weird readings on my logger though.
Maybe its a glitch, but the logger never showed the fuel trims cycling at all.
I will have to do another log to verify it wasnt just doing that that day.
O2 volts were dead stuck at like 2. something and my fuel trims were

ftrl- 117.1%
ftrm- 100 %
ftrh - 100 %

And I drove for about 20 minutes and they all stayed like that.
I kept the translator zero'd out for the most part, only thing I leaned out was the mid 2 clicks and the wot 1 click just to pull a little extra fuel since it had been so rich previously. I dont understand, why the trims would stay right there. Was the ecu in some kind of default, or learning mode. The battery was unplugged before then.
I mean I am happy with those fuel trims if that was what they really were but I think something else is going on.

Car didnt have any hint of knock at up to 24psi and it pulled about as hard as it ever had on pump gas from my memory, therefore it cannot be running that rich at WOT, because my car backfires and gets really sluggish if I go any richer than about 10.5 in the chip.
( I dont have wideband though so I dont have any exact numbers for AFR.)

Any ideas thanks.

 

[Black_Bullet]

Ok I finally got a wide band and its so much easier to tune the maft with a wideband to look at.

Well with the translator zero'd out and the injcetors set for 450's base, the car runs way too rich.
It too me 5 clicks on the WOT and mid fuel trim and 2 clicks idle to bring it to an appropriate level.

But as I said before, I am against really getting carried away tuning and playing with the gm maft knobs, and I dont want it to be more any inconsistent or anything.

So, Im taking a different approach w/ my tune, I zero'd everything back out, and then I set my base for 500cc injectors ( my fuel pressure is 48psi therefore rit gives my stock injectors a flow rate to 505cc's... Good enough, well anywys and after driving around watcing afr, I am pretty close and I only had to pull the WOT knob back two clicks.
The rest ar of my fuel trims are decent.

Anyone see anything wrong with doing it that way?

I think the fuelpressure is why i was rich when it was zero'd out?

 

[tunethis]

I see the wideband is working out well for you. I still don't have one. I don't see anything wrong with the way your doing it. As long as the A/F ratio is where it needs to be, you should be okay. I've heard some say you can't truly tune out fuel pressure overrun though. I guess once you turn the pressure down to the appropriate level, your tune should be even better. Even if it's only a little better. Someone else may be able to give you more information on your situation. I'm not all that familiar in this subject.

 

[Black_Bullet]

I see the wideband is working out well for you. I still don't have one. I don't see anything wrong with the way your doing it. As long as the A/F ratio is where it needs to be, you should be okay. I've heard some say you can't truly tune out fuel pressure overrun though. I guess once you turn the pressure down to the appropriate level, your tune should be even better. Even if it's only a little better. Someone else may be able to give you more information on your situation. I'm not all that familiar in this subject.

Ok thanks, and yea man you need to get a WBO2... I mean ive always needed one but my budget is tight, but I had to gone and break down and sacrifice and get one because this maft is so different than tuning the stock mas.

Also, Ive actually heard that 255lph's overrun the fuel press to about 48psi on the stock regulator from some tests ive read, and Id like to assume that since i am starting my base FP at 48psi, my overrun should be minimal?
A AFPR would be nice, and i know its always recommended to have w/ pump upgrade, hell ive told newbies they need them plenty of times, I just was always too cheap myself

So yea basically, I have 850cc injectors w/ 48psi base fuelpressure, therefore my chip is actually set at like 910cc or somethin like that and that properly compensated fuel, so I guess it would make sense to have my translator base setting at 500cc since if I was on stock injectors with this fuel pressure, thast about what my inj flow would be.
I am basically trying to get everything as CLOSE as possible before adjusting the knobs, and I dont want to have to adjust them more than 1 or 2 clicks, and I want the chip to take care of the rest. Setting it on 450s I was like adjusting 5 clicks leaner... Too much.

Also, by me setting my base on 500s or adjusting any of the knobs, will that inflate my timing?
Another reason im thinking just leaning out the base, but leaving everything else zero'd out.
I mean my timing is set in with my chip for different air flow gm/rev load rows, but I dont know if it will affect me the same as like ppl who tune these without chips/ or dsmlink. I guess if it did Id just have to go back in the chip and set the timing were i want it for whatever load row the maft puts me on...

Btw, I was reading my last post just now and I am actually surprised I was typing in readable clear sentences, because I was pretty tipsy last night when I got home and I dont know why the hell i was typing for... I think it took me like 5 minutes to think about what I was trying to say in that post

 

[chavez408]

Hey jay, I got a few questions for you. I see that the large plug that comes out of the translator goes into the stock plug that is left out of our maf. And the small plug with the little purple thing plugs into the gm maf. But I see two loose wires, one purple one and a white one. The purple one goes into the CAS for the rpm. But I see mix reviews that you do not need to hook it up. Do you only need to wire it up if you will be using the maft for tuning? Because I am not. Also what is the white wire for? Does that need to be hook up anywhere? What is this little purple rubber band for anyways?

 

[Black_Bullet]

Hey jay, I got a few questions for you. I see that the large plug that comes out of the translator goes into the stock plug that is left out of our maf. And the small plug with the little purple thing plugs into the gm maf. But I see two loose wires, one purple one and a white one. The purple one goes into the CAS for the rpm. But I see mix reviews that you do not need to hook it up. Do you only need to wire it up if you will be using the maft for tuning? Because I am not. Also what is the white wire for? Does that need to be hook up anywhere? What is this little purple rubber band for anyways?

No you dont use the purple wire at ALL.
You hook the white wire up to the CAS.
You do not need to hook it up unless you are running your maft in rpm mode.
If you arent using the thing to tune then screw the white wire, but i hooked mines up anyways just because...

And Purple rubber band ?

 

[chavez408]

Got it, well not really..
I did everything correctly and my car would not start. It will idle for a second and die. I removed the maft and install the 1gmaf and bam, she started right up. We figure something is wrong with the airflow wire. I'm trying to contact SBR for this issue.
no wires connected, aux set to 0 and base to 2.

 

[gsx951]

Unless you are running a bigger turbo and have some method for calibrating the MAF beyond the MAFT you are really better off running the OE air meter.

 

[Black_Bullet]

Unless you are running a bigger turbo and have some method for calibrating the MAF beyond the MAFT you are really better off running the OE air meter.

For simplicity of state of tune... Sure.

Otherwise the gm maft setup is better in every other way over the 1g maf.
If anything get a 2g mas or a evo mas and you will be good.

As far as your gm maft problems, what are the lights on the translator doing when you start it.

Check this site out

http://www.fullthrottletech.com/

 

[gsx951]

Otherwise the gm maft setup is better in every other way over the 1g maf.

If you're not running some kind of engine control like DSMlink, you'll never get this tuned.
The crummy MAFTranslator doesn't offer the control to do it.

I've been running a 3" GM MAF since 2003.

 

[chavez408]

I got dsmlink...
And it blink 7 times on me. That site didn't help me much.

 

[tunethis]

Got it, well not really..
I did everything correctly and my car would not start. It will idle for a second and die. I removed the maft and install the 1gmaf and bam, she started right up. We figure something is wrong with the airflow wire. I'm trying to contact SBR for this issue.
no wires connected, aux set to 0 and base to 2.

I think that thing you call a purple rubberband is to keep the maft plug and stock mas plug together since they are not a perfect fit like stock.

Are you running the newer 2.00+ version or older 1.3 version? Only the older version requires a zero setting for the aux knob. It only uses the base knob for the intial setup. On the newer versions you have to set the aux knob and base knob for your injectors.

This may help, if you haven't read it yet:

http://www.dsmtuners.com/forums/tun...k-huge-headache-wi-dsmers-please-help-me.html

 

[chavez408]

Yeah the version 2.0 something. If I remeber correctly tbe aux setting is suppose to be set at 0 since I own a 1g. And the base setting "2" is for stock 450 cc injectors. I have also zero all setting and I get the same issue. The car just won't start. I posted a log of me cracking the motor and I see atleast 18lbs/min while just cracking the motor...

 

[gsx951]

I got dsmlink...
And it blink 7 times on me. That site didn't help me much.

Well...there you have it.WTF

maftcalibrationbywbo2 [ECMTuning - wiki]

maftcalibrationbyloggedboost [ECMTuning - wiki]

http://www.jeffgst.com/gmafcalibration1.html

 

[chavez408]

I messed around with all those settings. I reseted all my airflow settings on my link, but I can't even start the car in order for me to calibrate the maft

 

[Black_Bullet]

1G / 2G DSM MAFT version 2.XX (Current Version!) - Full Throttle Speed Tech Support

7 blinks- Unit detected a reset while engine was still running...

So I guess make your main adjustments while the car is off but the key is on ACC mode.

If you're not running some kind of engine control like DSMlink, you'll never get this tuned.
The crummy MAFTranslator doesn't offer the control to do it.

I've been running a 3" GM MAF since 2003.

I mean I agree, the maf setup seems a bit more inconsistent than my 2g mas did.
But I dial in most of my tune thru my chip, and my translator is zero'd out for the most part.
My base i set for 500cc injectors though only due to my fuel pressure and my wot is leaned out 2 clicks, and the idle leaned out 1 click but other than that the other knob is zero'd out, and the fuel trims stay pretty good and its very driveable...

The only thing as of right now that im not liking is that it rains a lot here and I notice when it rains the AFR changes as much as .5 in open loop. Those mafts really dont like moisture, especially since I have a CAI;
But i am willing to deal with it since it will let me vent my bov ( Im going to a Tial )
and also the car can deal with having boost leaks a little better.
From switching the 2g mas to the Gm maft, I noticed a decrease in spool and transient boost response and the car pulled better up top in higher rpms, high boost.

 

[chavez408]

Aren't we suppose to do the settings with the key on ON position.

 

[Black_Bullet]

Aren't we suppose to do the settings with the key on ON position.

Yeah

 

[chavez408]

Ok well my laptop broke and my backup phone does not want to open those links up top. So I don't know if I am suppose to calibrate the maft before starting it. Ill give it another try before I send it to SBR.

 

[Black_Bullet]

Ok well my laptop broke and my backup phone does not want to open those links up top. So I don't know if I am suppose to calibrate the maft before starting it. Ill give it another try before I send it to SBR.

Dude just put the key in the ON position so that the translator gets power.
it should blink both lights or something.

Then set your base, and then zero everything out, and then start it and drive, and start logging fuel trims. Make the adjustments needed with dsmlink, and once all the fuel trims are near 100% and your afr on the wideband looks good, then start doing WOT pulls watching the WBO2 all the way thru the pull... Try to get a decent afr of 11.0-11.4 ish and once thats all set then your good.

 

[dsmmatt28]

What do you guys think about maft gen II. It has the wide band tracking you set your afr and it will adjust fuel to run that desired afr that you set. It controls timing and much more.