Does anyone know if the fuel can be 'turned up' on the GM/Isuzu NPR diesel trucks. I have a 1999 NPR/5-sp that is supposed to make 142 hp and I would like to increase that a little if possible. I know the automatic trucks made 175 hp and I think the engine is the same. Does anyone know if this is true? Does the fuel pump have an adjustment? I have pyro and boost gauges. The EGT's stay very low even when under a load. This makes me think there is plenty of room for more fuel. Thanks in advance.
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