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Discussion Starter #1
fuel pump not priming through relay will work if i manually power it and it has constant power in the brown/black wire if i remove the relay then the brown/black wire powers up for a few seconds like it should
 

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ok you aren't understanding how this all works.




here's how it works.


the black/white wire is powered by the bank angle sensor relay. your fuel pump relay is fed with a black/white on the coil side, a black/white on the contact side, then a brown/black on the coil side (that goes to the ecu) and a brown which goes to the fuel pump.


the black/white is +12v DC

the brown/black is connected to ground by the ECU to turn the relay on

the brown is the power to the fuel pump


here's a quick way to check.



turn the key on, with the kill switch in the stop position you should have 0 Vdc on the black/white

when you turn the kill switch to run, you should have 12 Vdc on the black white

if you don't have this, then you need to investigate the engine stop circuit. it starts at the ignition fuse (white/black), goes to the kill switch, comes back on black to the engine stop relay, then leaves on a red/orange to the bank angle sensor where it's connected to ground. any issue in this circuit will prevent 12v dc on the black white. it's pretty easy to diagnose this issue by a lack of FI lamp on the dash when you toggle the kill switch (when you click it to run, the FI lamp will come on for a few seconds as the ECU powers up, the ecu is fed by the black/white)


if you have power at the black/white, then you need to see if the ECU is calling for the pump to prime.

unplug the relay, put your meter between the black/white and brown/black. when you set the kill switch to run it should show 12 Vdc for a second or two, then go back to 0 Vdc.

if you plug in the relay, you should be able to feel the relay click on for a couple seconds, then off again as you cycle the kill switch.

if you're so inclined you can also put your lead between the solid brown and battery negative and verify 12 Vdc for a few seconds during the prime cycle



if you have all this, then the issue is further down the line


check for 12v DC between the brown and the fuel pump body. there's a green wire that bonds the fuel pump housing to the chassis. measure there.


if you have 12v going in, then it's likely that your issue is either a dead pump or a failed connection in the bulkhead that crosses between the outside of the tank and the inside. you can check for 12v at the pump motor connector itself.



chances are if you go through all this, you'll find the issue.
 

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Discussion Starter #3
ive got 12v going to the black/white wire i can toggle it off/on with switch but when its toggled on the fuel pump doesnt power up the only way i can get the fuel pump to come on is if i run a wire off the negative side of battery and ground it to the brown/black wire at the ECM it has a constant 12v not priming but if i unplug the fuel pump relay then the brown/black wire does what its suppose to when switched on there is voltage for a few seconds also theres no power coming out of the starter relay green/red wire ive done all kinds of tests but still fuel pump priming on its own
 

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man can you please try to write in a way that's understandable? there's not one single piece of punctuation in anything you've said, it's very hard to follow. i've already told you everything you need to know but i'm not entirely sure you read what i told you.

this is the last post i'm going to make here.


if grounding the brown/black causes the pump to run then you have found your problem.



you are still not understanding how this works though. maybe you need to reread my post.



when you unplug the relay there will be 0V on the brown/black. this is because you have removed the coil from the circuit (the black/white feeds the coil, when you unplug the relay you have removed the power from the circuit)



if you want to troubleshoot you need to unplug the relay then set your meter to continuity and check between battery negative and the brown/black. when you cycle the kill switch you should see continuity for a few seconds, then it should drop out.

similarly you could measure the voltage between the black/white and brown/black, it should go to 12v for a few seconds, then back to 0 V



i don't know what you're expecting on the green/red at the starter relay. that's the negative for the starter coil. there won't be power on it as it's grounded by the neutral switch. the only time you'd see 12v on the green/red would be if the bike was in gear, and the clutch switch was open and you were pressing the start button.
 

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Discussion Starter #5
ok when i remove fuel pump relay and test the brown/blk wire it has voltage, test light comes on and goes off like it should But when i plug relay back in the brown/blk wire has constant power
 

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Discussion Starter #6
and when i test for continuity in between brown/blk and black/wht wire it had continuity the whole time
 

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ok when i remove fuel pump relay and test the brown/blk wire it has voltage, test light comes on and goes off like it should But when i plug relay back in the brown/blk wire has constant power

it can't have voltage on it when the relay is unplugged. it's not connected to anything.

this statement doesn't even make sense. you say when the relay is unhooked, the brown/black is live, and then when you plug the relay in, the brown/black is live.


this is impossible.
 

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Discussion Starter #8
no when relay is unhooked the brown/blk wire has voltage for a few seconds like it should when i turn start switch to run position
 

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Discussion Starter #9
when relay is hooked back up with start switch in run position the brown/blk wire has constant power when it should only power up for a few seconds
 

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you don't understand how this works dude.


when the relay is hooked up there will be 12v on the brown/black wire because it's being fed through the coil on the relay. of course it has 12v on it it's supposed to.


when the ECU calls for the pump to prime, the brown/black is connected to ground, and will drop to 0v.



when the relay is not hooked up, the brown black is dead. the ecu does NOT power the brown/black ever. it will either be a dead wire, or connected to ground when the ECU calls for a pump prime. no relay = brown/black always dead. no matter what.
 

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it could be. or it could be a grounding issue.

when you ground the brown/black and the pump turns on, this is the same thing the ECU does. so if the ECU isn't doing that then it could be the ECU itself.

or...

is your FI lamp on? the ecu won't prime the pump if there are codes in the fuel system (injector loop check fail etc).


if you ground the brown/black and get the pump running does the bike start and run?
 

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Discussion Starter #14
my problem first started when i bought the bike someone put to big of fuse in the fan circuit , the fan shorted out and burnt the wire and it melted to some other wires, so i started replacing all the melted wires and it ran fine for a couple months then fuel pump went out, so i replaced it and now its acting like the fuel pump is out again. I tested this fuel pump and the old one they both work if i power them manually but wont prime when their connected to the bike wire harness. I dont know what else to check
 

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if it were me i'd pull the relay and jumper the black/white to the solid brown and then see if the bike will start and run. if it does i'd try a known good ECU. if something with 12v on it shorted to the black/brown it could burn the switch in the ECU.
 
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