Stand Alone Engine Wiring Harnesses for Sale - Fuel Injection New Stand Alone Engine Wiring Harnesses . At Fuel Injection Specialties, we build custom wiring harnesses that will simplify the installation of your GM fuel injected motor. All harnesses built by Fuel Injection Specialties are configured to plug into OEM components at their stock locations.Tech Specs · Parts Wiring Harness Professionals - fuelinjectionconnection Fuel Injection Connection Inc. or F.I.C. is here to serve you with the best quality EFI wiring harnesses for your dollar PERIOD! We want Fuel Injection Connection to be the first name out of the mouth of fellow street rodders and street machiners everywhere.