Running lean on one cylinder?

[Camaro38368]

Hi, I am pretty new to the fuel injection stuff and have a question about one cylinder seeming to be running a lot leaner than others. It is a gen2 dragbike, carpenter head and cams, stock pistons, factory fuel injection and ecm. Bike is dragrace only and doesnt get driven other than the racetrack. I have decided to put an 84mm piston kit in and when I pulled the cylinder head it looks like one cylinder is running pretty lean or else the other three are just running to rich. Bike ran perfectly and have put a couple hundred runs on the combination it had. There are no air leaks at intake boots or other signs of problems. Anyone have an idea if this is normal or something I should address and where to start?

 

[Camaro38368]

Hi, I am pretty new to the fuel injection stuff and have a question about one cylinder seeming to be running a lot leaner than others. It is a gen2 dragbike, carpenter head and cams, stock pistons, factory fuel injection and ecm. Bike is dragrace only and doesnt get driven other than the racetrack. I have decided to put an 84mm piston kit in and when I pulled the cylinder head it looks like one cylinder is running pretty lean or else the other three are just running to rich. Bike ran perfectly and have put a couple hundred runs on the combination it had. There are no air leaks at intake boots or other signs of problems. Anyone have an idea if this is normal or something I should address and where to start?

 

[Camaro38368]

Hi, I am pretty new to the fuel injection stuff and have a question about one cylinder seeming to be running a lot leaner than others. It is a gen2 dragbike, carpenter head and cams, stock pistons, factory fuel injection and ecm. Bike is dragrace only and doesnt get driven other than the racetrack. I have decided to put an 84mm piston kit in and when I pulled the cylinder head it looks like one cylinder is running pretty lean or else the other three are just running to rich. Bike ran perfectly and have put a couple hundred runs on the combination it had. There are no air leaks at intake boots or other signs of problems. Anyone have an idea if this is normal or something I should address and where to start?

 

[Kiwi Rider]

Looks like the 'lean' running cylinder is actually about the right colour, the others look too rich..... But the cause? Check the injector spray pattern for that cylinder and all electrical connector pins/terminals on that injector for corrosion and poor contact.
Check for battery voltage at the injector plug on one terminal. Should be above 10v.
Also check for continuity at the other wire in the inj connector to the Ecu connector plug pin.