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Discussion Starter · #1 ·
Problem started last year, with what seemed like the fuel pump not keeping up at high rpm (usually cutting out until rpms were dropped, on a couple of occasions dying completely), especially with the fuel level low in the tank. Driving like a granny and keeping the tank topped off seemed to fix the problem. Then, one day as I was picking it up from being towed (thank you, "vehicle cannot sit in one spot for 48 hours" ordinance) I picked it up, fired it up, drove it to the office to pay the company, went back out and... nothing. Not even noise from the fuel pump.

I thought the fuel pump had finally taken a dump after a long gradual demise, but I may have been wrong. Got a brand new unit from ronayers, put it in, and... nothing. Very, very aggravating. Anyone have any ideas on what may be wrong?
 

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check wire connections? sounds like you leave it in the weather? umm how about that ground wire under the tank. i remember some having trouble with that. i forget what bike was doing though
 

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fuel pump relay, and when you changed the pump you also did the filter right? Not that it would cause the problem just good thing to do....

just like the others already suggested kill switch turned on?? Don't know how many times i went stupid because of that one...
 

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What does "nothing" mean? Does it run the same as before, or won't start.

Reading the first part of your post have you ever tried opening the fuel cap when the problem starts? If you do and the bike runs better I say you've got a clogged vent.
 

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Discussion Starter · #6 ·
Reading back through it, I guess I wasn't quite as clear as I thought I was. By nothing I'm referring only to the fuel pump; everything powers up from my lights to my powercommander, but the fuel pump does not make any noise as it always has when the key is turned on and the motor won't fire. (Turns over fine.)

I've double checked all the wiring and fuses. I admit I know nothing about relays. Does this sound like it could even have a chance of being relay-related? I suppose it's possible that something else fried while the pump was slowly failing (my bike's gauges were smashed by a car, and it was no surprise that the fuel pump was going bad as I've run it out of gas many, many times.)
 

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Discussion Starter · #7 ·
Could someone maybe check to see if the fuel pump runs when the kill switch is engaged?

How would I check to see if the relay was burned up? I don't have my honda manual here...

Thanks all for your help. I'm pretty well lost with this problem.
 

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2002 Honda 919, 1976 Yamaha XT500 cafe, TC-JAG TZ250
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Time to roll up your sleeves!

You're going to have to be methodical here.

First, you will need a digital volt meter and one red and one black jumper wire about 3 feet long with aligator clips on one end and sharp probes on the other.

Second, look up the wiring diagram either in the service manual or in "Wrist Twisters Riders Forum > The Machines > Naked Bikes
Helpful Topics for 919 owners:" About 2/3rds of the way down in "Maintenance/Helpful How-To's" is a wiring diagram which will open in a separate window. I recommend saving it to a file in your computer for future reference. Familiarize yourself with the entire fuel pump control circuit including the pump, relay, fuses, grounds, and the relay control from the ECU. Take notes for reference while troubleshooting.

Here we go

Preparation:
Remove the seat and tail piece. Open the fuse box and check all fuses, then remove the headlight fuse. This will extend battery life during testing. Pull the middle of three relays away from its holder. This is the fuel pump relay, and your primary focus for much of the troubleshooting. With the meter, check for power to and from the 20 amp PGM - FI fuse. It is constantly powered directly from the battery (through the main fuse mounted on the starter relay). In all fuse tests, use the exposed metal lugs at the top of the fuses -- it's why they are there. If there is power to both sides, press on. Do not turn on the key unless directed to do so, then turn it off at the conclusion of each test.
Whenever I say Zero volts (0V), it can be as high as 1.5 V or even a little more unless I indicate otherwise.

Getting to the meat of it:

1-- Turn the key on and check for voltage at the Pink wire in the 22 pin gray connector at the ECU. This is a signal from a zener diode in the ignition switch that acts as an ECU reset. It is there to prevent the ECU from initializing if the bike is hot wired.
**** +11.5 Volts (V) -- Normal. Proceed to #2
**** 0V -- Either a broken wire or a defective diode, Find out which and repair / replace the electrical part of the switch.
**********************************

2 -- Making sure the kill switch is on, turn on the key and with the meter check for power at either Black/White wire going to the fuel relay.
**** +12V -- Cool. The EFI system is powered up. Go to #3
**** 0V -- Pull the engine stop relay (the one nearest the fuse box) away from the holder and check for power to the relay on the Red/White wire.
****** +12V -- The relay is getting power from the PGM fuse. Check the black wire for power.
********** 0V -- A problem in the kill switch or wiring. Fix it.
********** +12V -- The relay is getting power from the kill switch. Check the Red/Orange wire for power.
********** 0V -- The relay is getting a ground from the bank angle sensor. At this point, the relay is getting everything it needs to operate and may be defective.
********** 12V -- No ground from the bank angle sensor. Find out why.
***************************************************

3 -- Check for voltage at the Brown wire in the connector for the fuel pump relay for approx. 2 - 3 seconds after the key is turned on.
**** +12V -- The relay is providing power to the fuel pump. If the pump does not run, go to #4.
**** 0V -- Check for voltage at the Brown/Black wire in the connector for the fuel pump relay for approx. 2 - 3 seconds after the key is turned on.
******** Greater than 6 V -- There is insufficient ground from the ECU to activate the relay consistently. Possible poor connection or defective ECU.
******** Less than 3 V -- Normal reading. Cycle the key while holding the relay to feel for a click.
*********** No click. The relay coil may be open. Replace the relay.
*********** Click. Possible burned contacts. Replace the relay.
******** Between 3 and 6V -- Bad / intermittent connection between the relay and the ECU. Find and repair.
******************************************

4 -- Tilt up the tank and find the fuel pump / low fuel 3 pin connector. Wrap a clean shop towel around the red jumper's sharp probe to prevent shorting it to ground then clip the red wire's alligator clip to power at the starter relay. Be careful with the probe: it is hot at all times. Leaving the connector plugged together, jump +12 volts to the Brown wire in the fuel pump connector. Do not apply battery voltage to the Brown/Black wire. It may damage the low fuel sensor in the tank.
**** Fuel pump runs -- Poor connection between the relay and the pump. Repair.
**** Pump does not run -- Leaving the jumper in place, ground the Green wire with the Black jumper. Make sure it is securely grounded to the frame.
******** Pump runs -- Defective ground. The main ground for the most of the electrical system is on the right side of the frame near the rear of the tank. Check this for a loose bolt or corrosion. Correct as necessary.
******** Pump does not run -- Defective pump, broken wire between the 3 pin connector and the pump, or gremlins. Replace the pump, repair the wiring, or have an exorcism done (or whatever it takes to get rid of gremlins).

This may all look intimidating, but if you take it one step at a time you'll probably find the problem.

Rob
 
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hy.you have 3 relays under the seat.one of then has 2 black/white wires,one brown/black and a brown one.you have to measure battery voltage (with ignition swich and engine stop swich on)betwen brown/black(-) and black/white(+). if you have battery voltage thear thats mean the ecu is ok.then measure battery voltage betwen brown and ground.if nothing that's mean the relay need to be replacet,if you have voltage it's mean the pump or the wires from relay to pump are busted.measure battery voltage betwen green and brown at the pump connector.if you have it than the pump is bad. measure the voltage when you start the ignition on.the ecu is gonna gave you just for 2 seconds power on then,and afther you start the engine again.i undestand you have a pcIII. check the conectors.may be a bad contact.try without pcIII.
gerald
 

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Discussion Starter · #10 ·
Well, I certainly couldn't have asked for better! Thanks robtharalson! None of this should be a problem for me, I might get a chance to run through it tonight.

Thanks all-

ryan

You're going to have to be methodical here.

First, you will need a digital volt meter and one red and one black jumper wire about 3 feet long with aligator clips on one end and sharp probes on the other.

Second, look up the wiring diagram either in the service manual or in "Wrist Twisters Riders Forum > The Machines > Naked Bikes
Helpful Topics for 919 owners:" About 2/3rds of the way down in "Maintenance/Helpful How-To's" is a wiring diagram which will open in a separate window. I recommend saving it to a file in your computer for future reference. Familiarize yourself with the entire fuel pump control circuit including the pump, relay, fuses, grounds, and the relay control from the ECU. Take notes for reference while troubleshooting.

Here we go

Preparation:
Remove the seat and tail piece. Open the fuse box and check all fuses, then remove the headlight fuse. This will extend battery life during testing. Pull the middle of three relays away from its holder. This is the fuel pump relay, and your primary focus for much of the troubleshooting. With the meter, check for power to and from the 20 amp PGM - FI fuse. It is constantly powered directly from the battery (through the main fuse mounted on the starter relay). In all fuse tests, use the exposed metal lugs at the top of the fuses -- it's why they are there. If there is power to both sides, press on. Do not turn on the key unless directed to do so, then turn it off at the conclusion of each test.
Whenever I say Zero volts (0V), it can be as high as 1.5 V or even a little more unless I indicate otherwise.

Getting to the meat of it:

1-- Turn the key on and check for voltage at the Pink wire in the 22 pin gray connector at the ECU. This is a signal from a zener diode in the ignition switch that acts as an ECU reset. It is there to prevent the ECU from initializing if the bike is hot wired.
**** +11.5 Volts (V) -- Normal. Proceed to #2
**** 0V -- Either a broken wire or a defective diode, Find out which and repair / replace the electrical part of the switch.
**********************************

2 -- Making sure the kill switch is on, turn on the key and with the meter check for power at either Black/White wire going to the fuel relay.
**** +12V -- Cool. The EFI system is powered up. Go to #3
**** 0V -- Pull the engine stop relay (the one nearest the fuse box) away from the holder and check for power to the relay on the Red/White wire.
****** +12V -- The relay is getting power from the PGM fuse. Check the black wire for power.
********** 0V -- A problem in the kill switch or wiring. Fix it.
********** +12V -- The relay is getting power from the kill switch. Check the Red/Orange wire for power.
********** 0V -- The relay is getting a ground from the bank angle sensor. At this point, the relay is getting everything it needs to operate and may be defective.
********** 12V -- No ground from the bank angle sensor. Find out why.
***************************************************

3 -- Check for voltage at the Brown wire in the connector for the fuel pump relay for approx. 2 - 3 seconds after the key is turned on.
**** +12V -- The relay is providing power to the fuel pump. If the pump does not run, go to #4.
**** 0V -- Check for voltage at the Brown/Black wire in the connector for the fuel pump relay for approx. 2 - 3 seconds after the key is turned on.
******** Greater than 6 V -- There is insufficient ground from the ECU to activate the relay consistently. Possible poor connection or defective ECU.
******** Less than 3 V -- Normal reading. Cycle the key while holding the relay to feel for a click.
*********** No click. The relay coil may be open. Replace the relay.
*********** Click. Possible burned contacts. Replace the relay.
******** Between 3 and 6V -- Bad / intermittent connection between the relay and the ECU. Find and repair.
******************************************

4 -- Tilt up the tank and find the fuel pump / low fuel 3 pin connector. Wrap a clean shop towel around the red jumper's sharp probe to prevent shorting it to ground then clip the red wire's alligator clip to power at the starter relay. Be careful with the probe: it is hot at all times. Leaving the connector plugged together, jump +12 volts to the Brown wire in the fuel pump connector. Do not apply battery voltage to the Brown/Black wire. It may damage the low fuel sensor in the tank.
**** Fuel pump runs -- Poor connection between the relay and the pump. Repair.
**** Pump does not run -- Leaving the jumper in place, ground the Green wire with the Black jumper. Make sure it is securely grounded to the frame.
******** Pump runs -- Defective ground. The main ground for the most of the electrical system is on the right side of the frame near the rear of the tank. Check this for a loose bolt or corrosion. Correct as necessary.
******** Pump does not run -- Defective pump, broken wire between the 3 pin connector and the pump, or gremlins. Replace the pump, repair the wiring, or have an exorcism done (or whatever it takes to get rid of gremlins).

This may all look intimidating, but if you take it one step at a time you'll probably find the problem.

Rob
 

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I had a somewhat similar problem with my 04 earlier this year. Rob walked me thru it, bless his heart. Turns out I had a loose connection at the bank angle sensor. The loose connection was caused bt me jumping across it, btw. Ended up frying my ECU. Got a used one. All is well.
 

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2002 Honda 919, 1976 Yamaha XT500 cafe, TC-JAG TZ250
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While tracing out the circuits for the fuel pump, I decided to edit out all the extraneous B.S. to make it clearer. Here's the finished image. Copy it to your computer then open it in whatever viewer you use so you can zoom in.


If you find any mistakes let me know.

Rob
 
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2002 Honda 919, 1976 Yamaha XT500 cafe, TC-JAG TZ250
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Dear lord man, can I paypal you a gratuity for the work you've done?
Not necessary, but if you were to make a donation to the Wrist Twisters site it would benefit all of us. PM MisterMike for how to do it.

Good luck with the fuel pump problem, and if you get a result I haven't covered or are stuck post it with as much information as you can and I'll see what I can do to help. We gotta keep as many 919's on the road as possible!

Rob
 

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Discussion Starter · #15 ·
Fuel relay:

Brown - 0V at/after key on
Brown/Black - 12V same

So, would the fact that it started and ran fine 2 minutes before it conked out completely rule out a bad connection? I'm going to clean all connections anyway, but what are the odds I have to replace the ECU?
 

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Discussion Starter · #16 ·
Ah. I should also say that the ground to the ECU is good (.1 ohm to the frame). All the connections (at the ecu) are spotless.
 

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2002 Honda 919, 1976 Yamaha XT500 cafe, TC-JAG TZ250
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Fuel relay:

Brown - 0V at/after key on
Brown/Black - 12V same

So, would the fact that it started and ran fine 2 minutes before it conked out completely rule out a bad connection? I'm going to clean all connections anyway, but what are the odds I have to replace the ECU?
On the assumption that all the tests were performed in the order presented, it would appear the ECU is not picking up the relay at all -- which is very unusual in that I was expecting a reading somewhat less than 12V. If there is no drop at all it usually indicates an open circuit rather than an internal defect in the ECU, but it's always possible.

A quick test: Ground the Brown / Black lead then turn on the key. If the fuel pump runs start the motor. If it starts the ECU is initializing and the relay circuit is bad. If it doesn't try to start it is possible the Pink wire signal isn't picking up the ECU or the control unit is toast. I'll think on it further while making dinner and ge tback to you.

Rob
 

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Discussion Starter · #18 ·
Pink ECU wire was fine, 12v from both bl/wh wires at the relay, brown 0v br/bl 12v.

I will run out right now and do as you suggested.
 
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