Integra DC5 Type R cranking but won't start

[Walter Sobchak]

Does anyone have any idea what this could be?, sometimes it starts straight up fine and sometimes you need to crank and crank and it will splutter and eventually start, once running the engine runs fine, I don't think it's the imobilizer as you can hear the fuel pump engage, crankshaft sensor?, I'm really scratching my head with this one.

[Tc24]

Starter motor solenoid not engaging?