Problems with maft on stock injectors

[ed1380]

I'd like to preface this by saying that the system has been tested to 20psi with no leaks and I'm having problems only when using the maft.

I'm having a problem with the car going 10:1 rich as soon as I touch 1-2psi of boost and it starts bucking and refuses to accelerate. At idle and light accel it's good. I'm trying to set the maft for zero compensation because I have stock injectors and stock ecu, but my maft isn't like any of the manuals I've found.

Here's what the 4 knobs say. no idle, mid, wot like the 1.1, 1.3, and 2.08 version manual says

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and if this helps

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Thanks

 

[Sinister96]

Ok so i typed 3 papagraphs trying to help you, then i looked at the picture again and realized what you meant by not being like all the others you've seen. And then it dawned on me that i remembered reading something about that. You got the wrong Maf-T man. Its for a Buick, not DSM. DSM Maf-T are a little different and dont think they work correctly. Heres a link to what you have-http://www.fullthrottletech.com/attachment.php?attachmentid=582&d=1187014321
I'm pretty sure youll never get that to work on your car.
Once you get the right one let me know if you need some tips on tuning with it. The Maf-T is all i got to tune with and i've become pretty proficient at it, .

 

[ed1380]

I'd love to hear what you have to say. Or any help at all. It is a dsm maft. It has 4 switches and 2g made plug.

 

[Hal]

Older style MAFT

The docs are available on-line (google is your friend)

Hal

 

[bryanwheat]

Older style MAFT

The docs are available on-line (google is your friend)

Hal

This^. The knobs that say spark don't control spark on these. The knobs are injector comp,base, low and high. They are labeled like that because the same board is used for other cars. The chip is what is specific to the vehicle.

 

[ed1380]

I already have the 1.1 and 1.3 and 2.0 manual. I have it set to zero compensation. I'm on stock injectors and stock ecu with wastegate boost.

With stock maf wot gets me1600hz airflow. 10psi. 95injector%. 10.5afr. It pulls good.

Zero'd maft at wot as soon as it hits couple psi 8.5afr. 1100hz. 55injector%

Very weird

 

[Hal]

Unhook the white wire if it's hooked up.

Don't expect the hz to be the same, they won't.

You have to use the knobs to adjust the airflow curve.

 

[ed1380]

White wire in unhooked. I know the hz won't be the same, but 1100-1600 is a huge difference. 1600 is fuel cut on stock maf, but with the gm maf I'm hitting max ecu load at 2 psi.

 

[Sinister96]

Ok if thats the right one but earlier type then ill tell you what it took me to get my maf-t running good with stock fuel system. First thing first are you running the maf before or after turbo? If after you need to change the mode set-up for 3 1\2" if running a 3". Which would be 1 on - rest off. Then Do AUX-4 Base-2. Take a drive on a road without a lot of stops. get to 30 and keep it at 30 for as long as you can, log your fuel trims. Depending on logger you want them as close to 0 (100%) as possible. If they're over (positive) you need to lean out the BASE knob by turning it clockwise. If under (negative) you need to enrichen BASE knob by turning counter-clockwise. (BASE knob leans-and enrichens opposite of other knobs.) Each "click" adjust the trim by 5%.
Doing this will give you a optimum base tune. For me i had to have base on 1 for 440cc injectors, then enrichened the rest some.
Once your Base is set, take another drive. This time get on the freeway and log fuel trim at around 3000 rpm, (or make some 3k-5k pulls and log those). This is your mid knob which on yours im assuming would be the 3rd from left. For idle is used again the fuel trims while parked and in neutral. Timing is up in neutral. you want your Idle closer rich, mid a little richer and WOT or last knob rich. You have a A\F meter so once your base, idle, and mid is set, take another drive and watch A\F and fuel trims at about 5k they should go rich.
This is what i did and its ran great ever since. I dont use the "RPM" mode yet, as i was waiting to get my exhaust leaks fixed so i can get a tru reading from my ZT-2. But using that will let you dial in an addition 2% per "click".
If anyone has any better help for him and me in that matter please chime in. I'm going by the newest version of maf-t 2.01. I know in earlier versions the % was different or something.

 

[okm12346]

Did you reset the ECU? (unhook the battery)

 

[Hal]

Did you reset the ECU? (unhook the battery)

Why would he need to?

 

[ed1380]

to clear the fuel trims between settings. yup I did that too.

 

[okm12346]

Did you have the Aux 0, Base 2 (450cc injector setting)? As far as I know this is the correct setting. Base at 0 means you have had it for 10% bigger injectors.

 

[Hal]

to clear the fuel trims between settings. yup I did that too.

There's no need to do that.

It will re-trim by itself very quickly.

 

[ed1380]

Did you have the Aux 0, Base 2 (450cc injector setting)? As far as I know this is the correct setting. Base at 0 means you have had it for 10% bigger injectors.

Which would make it lean, but it was pig rich.

I played with the settings and aux4 base 2 did it. Its still a bit rich (9afr) but doesn't stutter. I guess that means I have a v2. Which is weird cause the PCB says 2003 and the v2 came out in 2004

 

[Hal]

The chip determines the version, not the PCB

When I was testing these years ago I'd just a new chip to try.

Pop the old one out, put the new one in