I just turbocharged my 2010 Sierra, its the on3 turbo kit so I removed the maf sensor. I took it to this tuner near me and said it would be easier to tune it with the maf sensor so they adapted It. But one month and half later and nothing. At first they told me it would completely cut off when wot but then it stopped and started tuning it. Got frustrated so I got it back yesterday. Truck still cuts off when you step on it. Put the scanner on it and says their a problem with the throttle body but I don't think so. Have you guys had a problem with this before? Want to make sure truck running good before taking it to Cunningham motor sports in Murrieta

 

Can you post the tune file and exact setup you are running?

Sounds like this tuner doesn't have a clue what he's doing. He was right in that you can fully tune the vehicle with the MAF sensor but it won't just "cut off" when you are in WOT.

 

They didn't give me the file. It's a stock 4.8 with 76 on3 kit, fic 1000cc injectors and a 3 bar map sensor I got from summit

 

You need to find a new tuner before you have to replace the motor. If no local options available do an email tune from someone reputable.

 

Find a new tuner asap. They obviously don't know how to tune around airflow limits causing maf/map, or map/tps correlation codes causing reduced engine power

 

Yeah just made an appointment with this shop about two hours from me , they had me thinking something was wrong with the truck. Hopefully motor didn't damage from the pulls they would do

 

ok something very similar happened to me. The on3 kit is not a perfect fit. Check the intake tube is not too far into the rubber piece that goes into the throttle body. If its too far in, when you press the gas and go into wot the butterfly will hit the intake tube, and not open all the way. You will know because there will be a slight scratch on the butter fly where itll hit the tube. post back if it solved ur problem i would like to know since i had the same issue.

I had to cut about 4-5 inches off the intake tube for it to work.


Also make sure if you updated injectors, that they are all seated into the injector hole and are not leaking when in wot.

im on maf too, and on3 kit. I had the same problem, so check the following first, then check for boost leaks, then check for preturbo leaks, then check tune.

Most important question: Can you replicate the issue without the tune? If so then it is something with how the turbo was installed.

 

At first I thought that was the problem as well but I checked it and it wasn't hitting. It only does it when you floor it from low rpms, but if I accelerate slowly to wot the truck runs good and gets boost

 

Had my appointment to get it tuned this past Monday and turned out my drive shaft was bent: . So getting one made at the moment

 

glad it wasnt the engine or turbo!