CM 870 ISX

[Kevroo]

This is getting frustrating!!! This is what I've got now after retune, truck stays cool on the pyro until I hit that 30 lbs on the boost then it climbs to 900, that 30 lbs is the max it will do. Truck fills week on power also. I've noticed when I let the fuel tank get below that half tank mark it stays cool as in won't go over 800 deg at 30 lbs boost even climbing a hill flat footed will not hit that 900 mark until I fill the tank? The truck will not get over 30 lbs for nothing. I thought I had all leaks found but using lots of soapy water. So could I still have a air leak? Or something with fuel? I just changed all fuel lines from tanks to filter. New fuel pump, all new sensors on motor. Can timing cause a problem like this. I just saw the post about plugging motor and pressuring for leaks, I didn't know that an air compressor can also be a problem? I'm just out of ideas on what to do. Forgot to mention going down highway at solid 20 lbs boost the egt stays at 600 deg. But climbing is horrible. Thanks for any help...