F4i issues with harness. Please help!
 

Just finished my stuntbike project yesterday. During the rebuild I pulled the entire harness out of the bike, and it was reinstalled and connected later. Upon attempted startup, there was no noise from the fuel pump. I get lights on the gauges and everything. The engine will turn over and over but will not start.

I have been researching this problem all day, it seems that if the fuel pump does not run for a few seconds when the ignition is turned on, the ECU is not sending signal to the fuel pump relay, the one that is next to the engine start relay. Ill try to lay out what I have and haven't tested..

1. I have tested the fuel pump by running power to brown, ground to green. It works.

2. Tip over sensor is correctly bypassed.

3. I took both wires running to the kickstand and soldered them together.

4. My engine start relay clicks on when I flip the run switch on and off.

5. The bike is in neutral, and neutral light is on. Also a red light is on on the left of the neutral light. Fuel injection light?

6. The fuel relay does not click! Not one bit.

7. I switched the fuel and start relays to see if one of them was bad. The fuel relay clicks in the starters spot. So the relays are fine.

8. I checked the main box of fuses, the main 30a fuse in the starters relay, and some little 20a fuse in a natural color fuse box near the relays. All fuses are good.
Somebody please help out! Its going to start getting warm soon and I need to be out stuntriding. :yeah

Re: F4i issues with harness. Please help!
 

ok, heres what you need to check. There is a diode in your ignition, and this will check to make sure it is still good. 1st get yourself a digital multimeter. now find your ignition plugs and on the harness side you need to stick the +tester lead on the pink wire, and the -one to the frame. Turn your key to the on position and turn your stop switch to run. You should have a reading of 9 volts. The other wires should read 14, 14, and 0. If you have these readings, then your diode is fine. If it doesnt read 9v and reads 14v like the others, then you need a new diode. The pink wire sends a 9v current to the ecu, which tells the fuel pump to prime. There is a way to bypass the diode though. Disconnect your ignition plug. You'll need to pull the leads out of the plug, or cut wires >(which is not recommended). Next connect all but the pink wire together, you should hear a clicking relay. Heres where it gets a little tricky. Get a 9 volt battery and some jumper wires. Connect the - jumper to the frame, and the + jumper to the pink wire. Turn the killswitch to run, and it should prime the pump and bike should fire up. You need to disconnect the 9v battery and the jumper wires and it should run for you. I hope this helps you out, I just had this exact same issue on my f4i and this worked. :yeah

Re: F4i issues with harness. Please help!
 

I broke down once on the road and my f4i fuel pump would not run unless the frame contacted the tank... it was a bad ground wire. I chased it through the harness and found a spot where the ground block had melted. (the green wires) doubt this is your problem as the relay isn't firing