01 honda cbr f4i electrical problem!?

Question

I really need some help on this one. So my fuel pump won't prime due to the unknow. The bike ran fine no issues except code 7, which is coolant temperature sensor. And also I got code 23, which is o2 due to me having aftermarket exhaust. Now with that said my brothers f4i fuel pump relay went out and I gave mine to test it if it'll fix the problem. It fixed his problem but when u put it in my bike the fuel pump won't prime. So we put it back on his bike and it worked! I bypassed the relay by jumping a brown/white and black/white wires. Fuel pump starts priming and I can start the bike just fine, it'll idel fine but chokes when I open full throttle. If I open throttle slowly it works fine. So far I have checked ecu by swapping mine with my bros it's works fine on his bike. I also check all of fuses they are all fine!! This is pissing me off! Can someone help me where can I look into it's the weekend and I'm missing out on some awesome rides. Help please.

Answer 1

Went through this on a friends bike same as yours. This bike had a low battery that needed to be kept on a charger if it was not ridden every day. That being said the worse thing for a relay is to run under lower than need voltage. His bike would start and keep running if you jumped it directly off of the battery. There is if memory serves me, a fuel pump relay-a fuel transfer relay and the tip sensor all located in the rear tail cowling. If you get lucky maybe the grommet came loose from the holder and everything is just hangin down instead of being upright. There are test that you can run on the pieces mentioned that will give ohm resistance and voltage readings and they can be found in a service manual. His problem because of low starting voltage, he had to replace both fuel transfer and the fuel pump. Seems weird that it would start off of the battery but I remember that it only uses 10 volts to trigger the pump from the relay and the low voltage killed them both. Oh yeah he had a full Yoshi exhaust on his bike.

Answer 2

When the bank angle sensor is activated, it turns off power to the fuel pump.

Suzuki's are notorious for bank angle sensors getting stuck in activation mode.

That's why racers by-pass them.

Maybe yours is working intermittently.

Swap the bank angle sensor with your bros bike.

Answer 3

Can only help you one way.

I'm going to take that awesome ride for you.



Sorry, but you might need to take it to shop with the proper equipment to read all the sh!t that's going on.

Guessing it's the sensor giving the chip the wrong read from your exhaust.