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Discussion Starter · #1 ·
I have a question about my fuel pump not coming on when I turn the ignition on.

First, some background. Two years and a few months ago, I laid my 929 down and cracked the engine block on both halves. I have replaced the engine, slowly, over the past 2 years. After finally getting it into one piece, I have replaced all the fluid and now want to try to start it.

When I turn the key on, I hear what I think is one of the relays. However, the fuel pump does not come on. As per the manual, I have checked the voltage at the fuel pump 3p (black) connector. there is voltage, however it is in the range of 7.9V dc - 8.0V dc, not 12. It also never goes away. (The manual indicates there should be voltage for a few seconds). I have checked the fuel cut relay, and it is working properly.

I also manually applied power to the fuel pump, and it sounds like it is working (I didn't do it for long for fear of burning it out if it is not supposed to be 12V).

Any advice on what else could be the problem would be appreciated.
 

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Check the bank angle sensor (tipover switch). It shouldn't be a problem, but if the bike hasn't run since the crash...
 

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Discussion Starter · #6 ·
I didn't get a chance to pull any codes or check the bank angle sensor, but I appreciate the help. I will get them checked this weekend and let everyone know :}
 

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Discussion Starter · #7 ·
Ok, I have checked the engine stop relay, the fuel cut-off relay, the bank angle sensor, and the engine stop switch. The main fuel fuse is good, as are every other fuse I can find.

The only check that I haven't done is the ECM check, but I don't see how that could cause this problem.

When I check the fuel pump 3P black connector (with the power on) I get exactly 7.41V, when the battery is reading 13.1.

I checked the FI error codes, and get none.

If I plug the fuel pump in directly to the battery, it sounds like it works fine.

Any ideas on what to check would be great, I don't want to start replacing parts that aren't broken.

Also, are there any other fuses other than the 30 amp main, and the 6-7 10/20 amp fuses in the box next to the 30A main?
 

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eScreaming Dizbuster
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The circuit is losing 5 volts between the battery positive post and the fuel pump connector. All you have to do is move the voltmeter probe progressively closer to the battery to find the fault. I suspect the relay.

With the ignition "on", there should be 12 volts at one of the fuel pump relay connector terminals. If not, the problem is between the battery and relay. Bad connector, bad wire, bad fuse. Replace all of the fuses, even if they look good. They're cheap, and they do wear out and corrode over time. Also take apart and reconnnect all wiring connectors.

If you have 12 volts to the relay, but less than that coming out, the relay is faulty. If you have 12 volts out of the relay but only 7 at the pump, the wiring between the relay and pump is faulty.

Basically you just need to systematically test for voltage along the circuit, until you find the point where it drops off.
 

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Discussion Starter · #9 ·
Ok, so I am dumb, but so is Honda :flame:.

Every wiring harness on this bike is different (for the most part) except for 2, the fuel tank/pump and the kickstand. Through very thorough testing, I have determined that plugging the fuel pump into the kickstand harness does not allow you to start the bike. Stupid Ray . . .

Anyways, the engine now starts, and runs ok, but once it is warm it quits running (like someone slowly turns the idle down until it quits). I haven't checked much, but the FI code it gives me now is bad map sensor (tho the book says the bike should run normally). Will continue to work on it, any help is still appreciated.
 

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eStarbucks
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Check your idle settings... Once warm it'll drop down to "idle" and if that's too low it'll just die.
 

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i just cleaned the tank on my 2000 cbr 929rr fireblade and now it wont start. the two hose clamps on the gas line that goes from the sending unit to what looks like the fule filter are striped and wont tighten would that cause the bike to not start? it is not getting any fule at all. any ideas???
 

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eModerator
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A loose clamp would not cause a no start unless it was allowing the line to come off the fitting. If it is not getting any fuel you need to check everything powering the fuel pump - wiring connections, fuses, relays, etc.
 
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