2007 Mack Ai E-7 427 Intermittent Turbo Lag

[quaddump]

can anyone help me out with this probblem i drive a 2007 mack granit with the E-7 AI427 in it the probblem is when accelerating hard loaded or empty the turbo will be going like normal then at like 900 to 1000 rmp it seems like the turbo boos is being cut back for like 300 to 400 rpm the it will hit back in like nothing happend it onley does it some time but not all the time any body got any ideas what the probblem could be the truck and engine onley have 55000 mi on it and i drive to trucks with the same probblem but the other one is a 350 in it

[Mackpro]

can anyone help me out with this probblem i drive a 2007 mack granit with the E-7 AI427 in it the probblem is when accelerating hard loaded or empty the turbo will be going like normal then at like 900 to 1000 rmp it seems like the turbo boos is being cut back for like 300 to 400 rpm the it will hit back in like nothing happend it onley does it some time but not all the time any body got any ideas what the probblem could be the truck and engine onley have 55000 mi on it and i drive to trucks with the same probblem but the other one is a 350 in it

Look back for to other post about same problems. There is a software and datafile for this problem, we do it all the time, it's called the "step 12B program with throttle pedal calibration". A good Mack dealer should know how to do it. Free download from Mack but you will have to pay for the labor to install it. Check out this post/thread http://www.bigmacktrucks.com/index.php?showtopic=11429