Intermittent no-start issue

[jermag24]

2017 Street Twin. I'm dealing with an intermittent issue where I'll hit the starter button and nothing happens. It only happens when the engine is warm. The smoking gun I noticed is that if I hear the fuel pump prime the engine when I turn the key on the engine will start. If the fuel pump does not prime the engine, nothing happens when I hit the start button. There's no way of predicting this, but I assume it has to do with the fuel pump occasionally not priming before engine start. Would this be a fuel pump relay issue? Thanks!

 

[atomsplitter]

Most likely the relay. When you turn the ignition on a series of contacts are made and one of those initiates the fuel pump's pressurization of the piping to injectors. If the pump doesn't pressurize the injectors can't deliver fuel, bike won't start. The relay when hot could open the circuit due to a cracked coil, replacing the relay is a fairly cheap first step to resolving the problem. If that doesn't do it, there are other places to look.

 

[jermag24]

Most likely the relay. When you turn the ignition on a series of contacts are made and one of those initiates the fuel pump's pressurization of the piping to injectors. If the pump doesn't pressurize the injectors can't deliver fuel, bike won't start. The relay when hot could open the circuit due to a cracked coil, replacing the relay is a fairly cheap first step to resolving the problem. If that doesn't do it, there are other places to look.

Do you know if the fuel pump fails to pressurize the injectors, that it will even fail to crank? Maybe there's a pressure switch that won't let the bike crank until the injector pressure is built up? I'll order a fuel pump relay regardless. Thanks.