"Fuel injectors are color coded. The color of the injector at the electrical connector determines lbs. per hour. 14 lb/hr are Grey, 19 lb/hr are Orange or Yellow, 24 lb/hr are Blue, 30 lb/hr are Red, and 36 lb/hr are Dark Blue. "
^^^^
From another site
Flex Fuel Rangers used 24lb thru 2000, and Flex fuel Rangers also used a Fuel type sensor at that time
Gas Only used 14lb
In 2001 Ford changed to 19lb for both Flex and Gas Only and changed computer software so no fuel type sensor was needed
The computer you use decides what injector size you need, the computer is programmed for that size injector, so it "knows" how much fuel will flow out of each injector if its OPENED for say 100ms with say 60psi pressure(1998 and up)
The computer would correct for injector size but only AFTER engine has warmed up and O2 sensors are working
So you could get RICH running at first start up, smoke
But after the first warm up the computer would start to decrease OPEN TIME of the larger injectors and set RICH Codes, but engine would no longer be running Rich
After next startup the computers Long Term Fuel Trims would correct for the larger injectors