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Discussion Starter · #1 ·
Hi all pulling my hair out with my 2007 ltr I cannot get it to start from the start button after a complete engine rebuild the problem seems to be that the fuel pump is no longer priming itself on turning the ignition key on I have checked all wiring twice but for some reason the pump does not get a earth connection coming from the ecu to power the fuel pump anybody have any idea why I would not be getting power to the fuel pump on turning the key on
 

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Discussion Starter · #3 ·
hi yes I have tested the fuel relay, tip over sensor for continuity and voltage they are both working as should be according to the manual when I turn on the ignition the relay will click and get power when I check the voltage at the fuel pump with a meter the only way I can get a 12 v reading on the meter is if I hold the black meter cable to a working earth cable then I get 12 volts but when I hold it to the earth on the fuel pump connection I get no voltage I have traced the earth cable from the fuel pump connection but it goes straight into the ecu terminal connection its as if the ecu is not putting out a earth to the fuel pump connection I am get power on all other switches on ignition turn on I just cant get power going to the fuel pump earth connection so it will not prime the fuel pump on start up any ideas what the problem could be why the fuel pump is not priming on start up. I have no trouble codes coming up just the bike refuses to start easily.
 

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Well it's possible the ECU is bad, but more likely that you have a bad ground connection. Do you still have the red switch on the left handlebar or did you remove the 'blob'?

Edit: I just looked over the Diagram. The Fuel pump relay gives you power to the fuel pump, the ground(earth) should be at the pump the whole time. You are missing a ground or have an open in the harness.
 

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Discussion Starter · #5 ·
i don't have the switch at the handle bars it has been done away with I have checked the ground cable visually and checked it for breaks in it electrically using a fluke I have checked it from the fuel pump connection right back to where it connects into the ecu terminal it just seems to be when I plug the ecu back in there is no earth connection being made if I connect a earth cable direct from the main earth cable at the battery and join into the earth cable where it comes out of the ecu to the pump the pump fires up straight away but on doing this it lights up the fi warning light as soon as I remove the cable the red light goes out but then I have no earth connection going to the fuel pump so it does not prime on ignition start up.
 

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Discussion Starter · #7 ·
any idea which cable it is that feeds the ecu with an earth and where would it be located at or do I need to trace the earth all the way back from the battery to the ecu to check that its getting a earth into the ecu is there a easy way to check this that you can think off.
am I right in thinking its the single wire with the 2 block terminal at the back of the starter solenoid that is the earth that must feed the ecu as the main earth cable is attached to the side casing bolt I did install a new sealed terminal to this cable but never thought of checking until now.
 

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Yes. the extra pigtail off the negative cable is the main ground for the entire system. if you dont have continuity between that connector and the B/W wire at the fuel pump you have an open in the harness.
 

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Discussion Starter · #9 ·
ok thanks for the help much appreciated I will start a fresh and start with checking that all earth cables are working going into the ecu as I presume the earth is just linked all together inside the ecu that then go to the other sensors switches that require a positive earth to work correctly would I be right in thinking this.
 

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Discussion Starter · #11 ·
your right that there are separate earths coming out of the ecu going to each individual connection where require what I cant understand is why the injector and other connections have a good earth connection coming out of the ecu but yet the fuel pump connection has no earth going to it surly if it was bad earth at the pigtail cable then none of the other sensors would be receiving a good earth connection or am I doing something silly and its an easy fix.
 

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your right that there are separate earths coming out of the ecu going to each individual connection where require what I cant understand is why the injector and other connections have a good earth connection coming out of the ecu but yet the fuel pump connection has no earth going to it surly if it was bad earth at the pigtail cable then none of the other sensors would be receiving a good earth connection or am I doing something silly
and its an easy fix.
I know this is an old Post, but did you figure this out?
I have the same problem and know exactly where your.comming from. I don't understand how I can be getting ground to EVERYTHING else but not the fuel pump with it running directly into the ECU.
 
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