Fuel Pump not priming, but it does with a weird trick, 2006 VFR800

Looking to see if anyone has had a similar issue to fast track my diagnostic process for my 2006 VFR800 Vtec.

I'm having a very specific issue with my fuel pump. When I turn on the ignition, the fuel pump won't prime, the FI light stays lit, and my aftermarket gear position indicator flashes F two times short and one long, repeating. Yet I have a way to start the bike every time from here.

If I want to start the bike I need to press the ignition for a few seconds, where the bike turns over without starting, turn off the bike, turn it on again, and the fuel pump will prime and start normally. If I don't try to start the bike with the FI error showing and just turn the ignition off and on again, the fuel pump will never prime. I need to try, and fail, turn off and restart, to then succeed on the next attempt.

I'd like to get to the bottom of this issue in case my "fix" stops working. From here I'm doubting the side stand or HISS, based on how my "fix" works. Same goes for the battery, it has been on charge for the last while as I've not been riding these past few weeks. The issue does not happen every time I try and start the bike, and it appeared before I stopped riding regularly.

Ill go through the following based on another thread, but like I said, I'm looking to see if anyone has had similar or can point to a promising fix based on my symptoms.

- Open or short circuit at the input power line of the PGM-FI/GN unit
- Faulty engine stop relay
- Faulty engine stop switch
- Faulty ignition switch
- Faulty bank angle sensor
- Faulty PGM-FI/GN unit
- Blown main fuse B (30Amp)
- Blown engine stop fuse (10Amp)
- Blown fule pump fuse (30Amp)
- Open circuit in engine stop switch ground wire

Thanks!
Stay on two wheels

 

Sounds like your Engine Stop Relay is not energizing correctly. The Fi light being On after switch on is an indication the ECM is not powered.

First thing I would try and only for test purposes is to bypass the Bank Angle Sensor.
Unplug the sensor and properly Ground the Red/Yellow wire going to the Engine Stop Relay coil.
If the engine starts normally you've found a faulty BAS, OR faulty wiring to it.

Also.......do a very close inspection of Main Fuse B 30amp. It and its wiring can suffer badly from overheating and high resistance connections. This power source feeds ALL your EFI stuff, via the ESR.

Verify you have good voltages at the ESR if you suspect an issue with the Relay itself, you can swap it with the Hi Beam Relay to isolate it.
The ESR must transfer power from the incoming 12v Red/White wire to the Black/White wire at Every Ignition switch on. Make sure the coil 12v on the Black wire coming from the Kill Switch is solid at every switch On.

Don't just guess or assume, take measurements! Do you have a wiring diagram of your bike?

Let's know how you get on.

Note....
-Your Sidestand switch is irrelevant for a Neutral gear Start.
- There is no Ground wire from the Kill Switch, its +12v.
- There is no dedicated Fuel Pump Fuse it uses Main Fuse B power.
- If your headlights are operating normally then there should be no issue with the Ignition Switch.
- Blown Main Fuse B or Kill Switch power Fuse = Totally Dead engine!

 

Mate thanks for the info! I'm having trouble starting the trouble shooting process as the issue now refuses to occur. I'll update the thread once I get somewhere.

 

You could at least carry out the inspection of Main Fuse B and its wiring as mentioned. It's the cause of many an intermittent issue.
You could be taking a risk of being stranded somewhere by not doing anything!