I am just confused about a few things. One, why would a bad injector cause the whole bike to die and fail to start especially on a 4cly engine? its like the bike is shutting itself down. Two, could the fuel pump going bad in some way trip this fault, say not supplying enough fuel to keep the last two injectors operating? The intermittence of this issue seems to sujust to me that ether something is failing slowly when its hot, or i have a pinched/croded/nicked wire that is shorting out. I don't have a lot of experience with vacuum lines as H60 Helicopters don't have those. could they cause an intermittent fault?
No doubt your HC60s work is blessed with sophisticated diagnostics capabilities.
Not so here, this is old school given that no such stuff exists for the 919.
The only thing missing is points, condensors and carbs.
There could easily be, and very likely, that there are multiple issues, some of which are likely not directly linked.
Elimination is required to the degree possible in order to narrow down the possibilities.
It sounds as though you bought the bike used.
You have a Cali' bike and can only assume that someone before you removed the Evap system, so right away tank venting and the TB vacuum arrangement is suspect and needs to be checked.
Make sure tank is venting properly and that all 4 of the TB vacuum ports are properly blocked off, cap type plugs suggested.
The FSM has an error re the hose schematic for the MAP hose network and the FPR feed.
Pg 5-66 incorrectly depicts which vacuum tap to use for what purpose re # 2 cylinder by showing them as reversed. (The FPR relies on connections from the inboard side of the #2 & 3 TB's)
So that also needs to be checked out.
You have a PC3, and given all you are starting at, it would be unwise not to remove it from the equation, and it's quick and easy work. (see Rob Tharlson's earlier post's comment about back to Zero)
Someone or some have been under the tank doing things. Like a car, sensors and connections have higher probabilities of failure than components do. There are sensors under the tank, and the cam position sensor is in the work zone, so check the connection there and eyeball things for any visible damage.
Perhaps the #3 injector connection has been damaged, but only acts up intermittently.
But that doesn't explain why the ECU was displaying codes for the entire bank of injectors.
Anyway, check the connections for #3 and see what that reveals.
IF after all the above you are left with a code for one duff injector at #3, do per Islandboy's suggestion to swap it with another, and see what happens.
The fuel pump could be involved, but if it cycles through its normal sequence during the start cycle and "sounds right", my guess is that it's not involved unless the filter is blocked, and even then, that would be a filter issue, not a pump issue per se.
Of course, all the above is predicated upon the assumption that the Kill Switch is not at play, nor the continuity at the key lock............................
By the way, how long ago has it been since anyone touched the bike with tools?
Hopefully the above helps you some, and you can count on others to also chime in.