I have a 2007 Suzuki Boulevard C50T that I just had the engine replaced. Found out that the rear injector was only firing every once in a while. Checked the injectors, also, switched them, both are working fine. Checked the wiring, even jumped the wire, everything is good. Checked ECU and even replaced it. Checked spark plugs, they are good. Everything has been checked numerous times, and by all accounts, it should be working. But, cannot get the rear injector to fire consistently. Any ideas at to what we are missing?