solubility of air in the cleaner from which it might have been expected that the oxygen contained in the liquid leaving the container would not significantly affect combustion of the fuel nevertheless the beneficial affect on engine performance when compressed air is used as a propellant is dramatic possibly because of the extremely homogeneous nature of the mixture of air leaving solution with the atomized droplets of the essentially combustible cleaner an intimate mixture which results in greatly superior combustion the relative amounts of air and liquid present will depend upon a balancing of considerations including safety factors the duration of cleaning required and similar factors while such ratios can be varied within a considerable range it has been found desirable to have a volume of liquid in the aerosol canister equal to about 25 to 90 on a volume basis of the total space available a volume of about 50 to 60 however is preferred the balance of the space commonly termed the 34 head space 34 being filled with the compressed air propellant various liquid cleaners are suitable for cleaning fuel injectors commonly however they will include in addition to materials suitable for dissolving organic contaminants dispersants detergents dispersant and detergent solvents lubricants mixtures of the preceding and.