GM and MAFT reading incorrect

[BlackHawkAWD91]

Pretty much what it says. The problem has come and gone a couple times. What happens is usually I see around 3200-3400 karma on SAFC at 7k area. Car pulls great. However, tonight with no changes at all, I start seeing 3600-3800 at like 5k. Boost is rock solid at 20PSi. I checked all electrical plugs.Unplugged and checked, all dry. As soon as the Karma gets crazy, the car just starts bucking, and almost shutting off and coming back on. I think its because the computer sees LARGE amounts of air and and gives it the fuel for it, when actually the engine has no were near that much air flowing

What would cause this? My GM is descreened, but has been for over a year with no problems. I am running water injection, but this problem has happened before with no injection. Also i am 100% sure it is not a boost leak, one it has happened before and one pull later went away for months. Also, it was boost checked last weekend.

Most likey a 3in GM mas, or is it my MAFT?? Any other items?? Check profile for setup questions.

Any help would be great, Thanks a lot guys.

 

[LucasEnglish]

I have found the Maft to over compensate when it is cold or raining out. My car on a 60+ deg day will be tuned to a 11.5-11.8 AFRS but as soon as it drops under 50 deg or is raining out even with a non cold air intake it will be in the mid 10s AFR.

I have seen a few MAF's go bad. I have also had good luck cleaning them out with break clean.

Just some Ideas. Please let me know what you find.

 

[Thomas91169]

clean your maf.

step 1 in all things having to do with gm/ford troubleshooting. lots of things work but i use terminal/connector cleaner, take the maf off, spray a little bit onto the element, and reinstall.

 

[BlackHawkAWD91]

Fixed her. Maf was wet. It turns out the water from alky injection was running down the pipe from the elbow to the blow-thru setup. I took the maf out and dryed it with a hair dryer for about 10 minutes. Then I turn the boost sensor on the alky to come on at 14PSI instead of 10. I think this will help keep the water moving in the right direction. So far, so good.

Thanks for the tips!!

 

[Maglin]

Well the previous poster is right about the MAFT accounting for more air at lower temps. I've seen it as well on my WB. Their is definilty some issues with the MAFT. The GM MAF does all the density compensations in the MAF just by it's nature of a Hot Wire. Also why Water in the MAF caused it to read so high. It cooled off the hot wire which would indicate a lot of air flow normally. I think a MAP based SD system is really the only way to get around a lot of these issues.