You do not need the stock barometer or IAT sensor with a GM maf.
I don't know the fuel trim system on the 2g's, so I can't help you there.
If you are running rich, adjust the injector compensation on the maft to a larger injector size not smaller.

 

I would like to use them to keep from having to adjust my tune every time the temp/ weather changes. I read something that you can use the stock maf for the baro/iat to help that.


I did adjust the maft to bigger injectors and it ran worse. The maft manual said to adjust to smaller injectors if it's running rich. I got it were it's not running rich now(at idle) still tuning the wot.

 

I might be wrong on the injector compensation, but I don't think I am. Agree to disagree.

I haven't heard of wiring in the stock sensors before. From a theoretical standpoint, the IAT sensor is not necessary because warm air cannot cool the hotwire setup as much as cold air. As far as compensating for atmospheric pressure, the maf relies on the number of air molecules passing by it to get a proper reading and should also be able to send a correct airflow to the ecu.

In my experience, the maft doesn't really need to be fiddled around with that much anyway to warrant additional sensors.

 

If it's cold the hot wire will cool off more correct? So the car will think there is more air entering engine and run rich or am I over thinking. I'm a Ford tech and I know that baro and iat will effect the way Ford's run. So is this the same case?

 

Should be, the general idea is the same on hotwire systems.
Karmann vortex on the other hand.........

 

Anyone have any problems with tune changing on a maft set up?

 

Yes! Biggest PITA so far... wishing I would have went with Link.

 

The temperature of the hotwire is an offset of the iat. With a simulated iat and a changing ambient air temp, the tune will not be constant with temp changes. In a GM vehicle, the iat is not used to calculate airflow it's only for reference for the hotwire temp. Even if the stock ecu gets an air temp reading, the translator will still use a fixed temp offset for the hotwire and the airflow reading will change with air temp. Coupler size and placement on the GM sensor will also affect the reading. If you are outflowing a 2g maf, or want to vent your bov, you should consider ECULink v3 since you can run it in speed density mode.

 

I have Link w/MAFT.




No problems here... Honestly I duno why some people claim they have issues with the tune changing. If you stop with the theory bs, and actually research the MAFT. There is no reason for this. The only reason I can think of this would be some variable changing in the MAF translator it's self.

 

It's no theory, I have witnessed it first hand. I also have Maft/Link and when there are large temp swings here, around 20*, the AFR will change. It happens to my car up to .5 change in afr and fuel trims changed.

 

So has anyone read anything about using the stock maf for the baro/iat? Wouldn't this fix the tune from changing? I read somewere that a guy used the stock maf for the baro/iat and he said that the problem was fixed, but I can't find where I read it.

 

No the maf-t box simulates the dsm maf. You can only use the baro/iat for logging inputs like, map, wbo2, iat.

I run the maf-t with ecmlink and I have the "wondering tune" that it causes. Really not that bad.

I will be switching to speed density real soon.