I have a 2006 Hyundai Terracan 2.9 CRDi. It is lacking power on the bottom end to the point that it can't make it up steep inclines and is dangerous getting out into traffic. Once the turbo kicks in it is fine. While going up long hills (we live in Costa Rica) the transmission (automatic) has to kick down a lot because the engine just bogs down. We have cleaned the injectors twice, as well as had the injector pump cleaned. We have purged the filters and the fuel lines. We have checked the vacuum lines and one was off and after putting it back on the performance increased a bit, but not to the normal point. It started doing this after we had a leak in the injector closest to the firewall which was causing an airlock and the truck wouldn't start. We fixed that injector and replaced the sensor (in Spanish it is the Sensor Arbol Cevas - no idea in English) that is closest to that injector (top of engine close to firewall). Since that repair we have had this problem. The air cleaner is new. I am not sure where to turn now. Help.