PLEASE HELP 2003 Honda CBR600RR Fuel Pump Won't Prime
So I bought the bike from a local rider, he had said it needed a fuel pump so I figured no problem. Have had it looked at 3 times by 3 different technicians all with different solutions. One said Ecu so Got a new one, another said fuel pump so got a new one, last one said relay but couldn't find a faulty relay. Any help would be greatly appreciated as warmer weather is here and I'd like to be out catching wind with my brothers! Thanks in Advance and Safe Rides!
@608CBR600RR Hi and welcome to the forum. On Honda fuel injected bikes there are 2 relays involved with the fuel pump, the Engine Stop relay and the Fuel Cut Relay. Both of these relays are controlled by the Bank Angle Sensor (BAS). The BAS is what provides a ground connection for these 2 relays to work. The BAS is what turns off fuel flow to the engine, if the bike falls over. So, some checking needs to be done using the wiring diagram and a meter to see if these things are working. Did any of the 3 technicians actually do any diagnostics?
The one who stated it needed an Ecu did a run-through with a multimeter, also the 3rd checked all relays. Have went and looked after your reply and seen the BAS(Bank Angle Sensor) is Bypassed. Do I unbypass is and put a new BAS on? Thanks for Your Time and helpfulness.
I don't understand why everyone bypasses it. Here are some questions I have.
When you say the "3rd check all relays", what exactly does that entail? There are 2 specific relays that I mentioned before that will allow power to be provided to the fuel pump. When you turn on the Ignition Key, do those 2 relays turn on? If they do, are the providing the proper voltages to the right destinations, ie, is power getting to the Fuel Pump? Going to need a shop manual and wiring diagram to check these things. Do you have them?
When you say the "3rd check all relays", what exactly does that entail? There are 2 specific relays that I mentioned before that will allow power to be provided to the fuel pump. When you turn on the Ignition Key, do those 2 relays turn on? If they do, are the providing the proper voltages to the right destinations, ie, is power getting to the Fuel Pump? Going to need a shop manual and wiring diagram to check these things. Do you have them?
@608CBR600RR , did you get this resolved? Most likely those *%#$! relays. They fail when you just look at them wrong. I usually just chop them all off and solder in new sockets for standard Bosch relays. Double capacity (40a) and they're so much more reliable with coated terminals.
Go through this guide and post numbers of each step you measured. The numbers you measured will say exactly what's wrong.
https://www.600rr.net/threads/diy-st...-03-06.589929/
Last edited by dannoxyz; May 16, 2023 at 09:24 PM.
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