NOVELTY - Diesel fuel for fuel injection, comprises: a major amount of middle distillate fuel; and a reaction product of (i) a hydrocarbyl substituted dicarboxylic acid or anhydride and (ii) amine compounds (A) or its salt, where the reaction product contains at least one amino triazole group and is present to improve the performance of diesel direct and/or indirect fuel injectors.    USE - The diesel fuel is useful for improving the injector performance and cleaning fuel injectors of a fuel injected diesel engine (all claimed).    ADVANTAGE - The diesel fuel is completely free from succinimide dispersants. The fuel additive inhibits/reduce the deposition of undesirable dirt on the diesel injection injectors and also effectively cleans the fuel injector, thus enhancing the performance of the fuel injectors of diesel engine.    DETAILED DESCRIPTION - Diesel fuel for fuel injection, comprises: a major amount of middle distillate fuel; and a reaction product of (i) a hydrocarbyl substituted dicarboxylic acid or anhydride and (ii) amine compounds of formula (H2N-C(=NR)NH-NHR1) (A) or its salt, where the reaction product contains at least one amino triazole group and is present to improve the performance of diesel direct and/or indirect fuel injectors.    R = H or 1-15C hydrocarbyl; and    R1 = H or 1-20C hydrocarbyl.    INDEPENDENT CLAIMS are included for:    (1) a method of either improving the injector performance or cleaning fuel injectors of a fuel injected diesel engine comprising operating the diesel engine on a fuel composition comprising major amount of fuel and a reaction product derived from (A) and hydrocarbyl carbonyl compounds of formula (C1);    (2) a fuel additive concentrate for addition to a diesel fuel for improving the performance of fuel injectors for a diesel engine comprising a reaction product derived from (A) and (C1); and    (3) a fuel comprising a minor amount of the additive concentrate and a major amount of fuel, which is middle distillate fuel, diesel fuel, bio-renewable fuel, biodiesel fuel, gas-to-liquid fuel, jet fuel, alcohol, ether, kerosene, low sulfur fuel, synthetic fuel such as Fischer-Tropsch fuel, liquid petroleum gas, bunker oils, coal to liquid fuel, biomass to liquid fuel, high asphaltene fuels, fuels derived from coal (natural, cleaned, and petcoke), genetically engineered biofuels and crops, their extracts and natural gas.    R2 = hydrocarbyl having average molecular weight of 200-3000 or 500-1000 daltons.