Let  design a system for gasoline vapor injection derived from CNG systems.
I have Fiat Grande Punto 1.4 L 16 V 70 Kw 95 bhp from 2009.
Components list:

CNG/LPG Emulator   http://ji14135.en.embiz.net/p730086/CNG-LPG-Emulator.aspx

cng injector rail   http://www.aliexpress.com/wholesale/wholesale-cng-injector-rail.html

Air Compressor Pressure Switch Control Valve 90-120 PSI    http://www.ebay.com/itm/Air-Compressor-Pressure-Switch-Control-Valve-90-120-PSI-/290589699710?pt=UK_Air_Tools_and_Compressors&hash=item43a87eee7e

high pressure cylinder 0.2 to 1 L i think will work something like   http://www.aliexpress.com/product-gs/381721063-1L-high-pressure-cylinder-wholesalers.html

liquid Level sensors  http://www.aliexpress.com/wholesale?SearchText=liquid+Level+sensors&catId=0

a gas solenoid valve to use as gas vapour injector in air intake

we need to design a housing for an electric heat rezistor and level senzor were liquid gas will go in level senzor cut off the pump, the electric rezistor will heat to something like 260 degress celsius a quantity of 1-10 ml of gas it will need to be powerfull enough to vaporize 5 liters of gasoline per hour (please calculate the needed watt value for rezistor) .   After gas its vapour will build up pressure in  high pressure cylinder and Pressure Switch Control Valve will cut power to the rezistor when target pressure wil be reaced.

Please if you can find more info about used oil furnaces (i sow on discovery on how its made show http://www.youtube.com/watch?v=M1905eRMyDo   time 3:21  they used 100w rezistor )

They use something like pencil heater or cartidge heater

http://www.alibaba.com/product-tp/111819836/Pencil_Heaters.html
http://www.heatersplus.com/products/cartridg.html
http://www.aliexpress.com/product-fm/486753633-PTC-heating-units-50W-wholesalers.html
http://www.heaters.in/cartridge-heaters.html#pencil-heaters
http://www.directindustry.com/industrial-manufacturer/cartridge-heater-73498.html

lpg kits components : http://www.indiamart.com/agfautogas/products.html   we can use as injector the LPG Solenoid Valve  and please find about the working temperatures of the LPG Electronic Vaporizer

Let's join forces and design this system and enjoy the benefits in daily life.

Hi D,

The problem with vaporized gasoline motors is that the gas is so loaded with additives and impurities that it will not run correctly because all the additives will not vaporize at the same temperature.  The best fuel to use for vaporization is ethanol.  It will vaporize at a lower temperature then water and you can build a dedicated engine with high compression and get a lot of power.  These engines have been created, you can use a diesel engine to start and lower the compression slightly.  Then add your ignition system, gaseous carb or fuel injection (like from a forklift) and enjoy the great mileage.  Do some searching on the net you you will surely find plenty of material.  Let us know if you build one.
Mark