The short answer is no (the long answer is too complicated), you can't run a diesel too lean. fuel quantity regulates engine speed which in turn will regulate the amount of boost the turbo can make.
To me it sounds like your turbo has a weak actuator spring and it's opening too soon - fitting the boost controller has artificially "strengthened" it. so I would be fitting a new actuator before you do anything. So your car is basically now performing as it was intended.
Pretty much no smoke is what you want. if you have access to something that can measure the AFR you'd probably want to target anywhere between 16-20:1 at full load.
We really need to leave this "light haze" stuff back in the 90's - a time when diesel tuning was a relatively new thing. It's a very rough guide and it's totally useless if you've got a downwards pointing exhaust tip and small mirrors!
To me it sounds like your turbo has a weak actuator spring and it's opening too soon - fitting the boost controller has artificially "strengthened" it. so I would be fitting a new actuator before you do anything. So your car is basically now performing as it was intended.
Pretty much no smoke is what you want. if you have access to something that can measure the AFR you'd probably want to target anywhere between 16-20:1 at full load.
We really need to leave this "light haze" stuff back in the 90's - a time when diesel tuning was a relatively new thing. It's a very rough guide and it's totally useless if you've got a downwards pointing exhaust tip and small mirrors!
A moments silence please, for our brothers in the NAD-zone.