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Easyrider

Fuel pump issue

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Need a little help from someone that has more knowledge then me this one has got me stumped. The bike is an 04 vfr800. The issue I’m having is the fuel pump won’t prime. The bike will turn over but I’m not getting any priming sound out of the fuel pump. I’ve seen other topics about this and have done some research but can’t seem to track it down. I’m getting 12v at all the relays and 12v at the fuel pump connection when it’s unplugged but when it’s Plugged into the fuel pump and I back probe the wires I’m getting 0v. Also when I connect the fuel pump directly to the battery with jumper wires I can get it to prime. It doesn’t make any sense to me that I have 12v at the end of the connection going into the fuel pump and I know the fuel pump is good because it kicks on when I hook it directly to the battery but it still won’t kick on under normal circumstances. Any help would be greatly appreciated. I’ve spent a week on it and still no luck. Thanks

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At switch on the ECM provides the Ground to energize the Fuel Cut Relay for 2 seconds. So on the 12v side of the relay (Black/White wires)Yes you will see 12v all the time because you probably have your black meter lead on frame. However, to energize the relay the ECM controls the Ground to the relay via the Brown/Black wire.

 

Your comment:

" It doesn’t make any sense to me that I have 12v at the end of the connection going into the fuel pump and I know the fuel pump is good because it kicks on when I hook it directly to the battery but it still won’t kick on under normal circumstances. Any help would be greatly appreciated. I’ve spent a week on it and still no luck. Thanks"

 

This makes me think the Green wire of your Fuel Pump connector is NOT properly Grounded, make sure it has continuity (Zero Ohms) back to the Battery Negative terminal. Don't forget that at switch ON there will only be 12v for the Fuel Pump for approx 2 seconds.

 

Check this first. Let's know how you get on.

 

 

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I think your on to something. I’m reading 30ohms if I hook one end of the meter to the ground and the other to the negative on the battery. So new ground wire? Where do I run it from?the ecm to the frame? Sorry I’m an idiot when it comes to electrical stuff. Guess I’m going to learn a thing or two if I keep this bike.

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27 minutes ago, Easyrider said:

I think your on to something. I’m reading 30ohms if I hook one end of the meter to the ground and the other to the negative on the battery. So new ground wire? Where do I run it from?the ecm to the frame? Sorry I’m an idiot when it comes to electrical stuff. Guess I’m going to learn a thing or two if I keep this bike.

Let me get this right! 

So you are saying from the Green wire of the Fuel Pump connector to the Neg battery terminal you see 30 ohms?  If so then that's the fault. You must see near Zero Ohms to Ground for this wire (Continuity).

 

To test the whole system. Make up a wire connected to the battery Negative and the other end neatly spliced into the Green wire of the Fuel Pump. Plug in the Fuel Pump connector. Switch ON, does it prime for 2 seconds? Can you start your bike?

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I killed the battery trying to crank on it. I’ll give it a try when I get the battery charged up

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3 minutes ago, Easyrider said:

I killed the battery trying to crank on it. I’ll give it a try when I get the battery charged up

Did you at least hear the Fuel Pump prime? Before you started cranking!

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Ok got the battery charged and tried to jump the ground with a alligator clip Directly to the negative on the battery still not priming. Tested the Ohms from the ground On the fuel pump connection to the negative on the Battery and got like .1 ohms so I must of been doing something wrong when I tested it yesterday. I took the tank completely off the bike so I could get a better look at where the wires were running to and while I had it off the bike I hooked up a battery With two jumper wires to the fuel pump connection and it kicked on and made the whining Sound like when it primes. So I went back and tested the brown fuel pump connection by probing the green wire and the brown wire Directly where the copper tabs from the fuel pump stab into it and got 12v for a few seconds after I turned the key on. I’m going in circles with this thing. It makes no sense to me. Is it not putting enough amps to run the fuel pump? 

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Are you confident the Fuel Pump Green wire is now Grounded? 

 

Hang in there, you have at least confirmed the ECM and Fuel Pump are working correctly. Your problem should be a simple one!!!!

 

Try this.

- Remove the Fuel Cut Relay.

- Make up a jumper wire.

- Place the jumper link between any of the two Black/White wires and the Brown wire. NOT the BROWN/BLACK wire.

- Have the Fuel Pump Connected.

- Kill Switch to RUN.

- Ignition to ON

Do you hear the Fuel Pump run continuously ?

 

WARNING - DO NOT JUMPER THE BLACK/WHITE to the BROWN/BLACK WIRE You Could Destroy Your ECM.

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The next thing I would check is if the terminals inside the fuel pump connectors are such that they guarantee a good connection, perhaps clean and tweak them so the connection is tight.

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2 hours ago, raYzerman said:

The next thing I would check is if the terminals inside the fuel pump connectors are such that they guarantee a good connection, perhaps clean and tweak them so the connection is tight.

Great point. I've just assumed the OP with all his checking at the fuel pump connections would have checked this. His strange reading of 30ohms to ground of the Green wire has thrown me off track a little.

I am sure his issue will be a simple one as he has at least seen 12v at the Fuel Pump wiring for 2 seconds at switch on, meaning at least the ECM is working correctly.

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Thought it might be the wire connection so I cut it off and hard wired it to the fuel pump and it still won’t prime. With the wires disconnected from the fuel pump I get 12v but once I hook the wires up and test it I get between .5-1v. So does that mean that it’s grounding out inside the pump itself. If that’s the case then why does it prime when I jumper wire it directly from the battery. I appreciate the help. Without your advice I would be completely lost. Thanks

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Ok so you've soldered the fuel pump wires to the pump connections. That isolates any bad connection scenario at the pump.

If you can operate the Fuel Pump from your battery direct then there's nothing wrong with the pump!

Just have a test wire connected to battery Positive and touch the other end carefully to the pump Brown wire terminal. Does the pump run? If yes that confirms the ground wire is ok. And your Brown wire could be the issue.

 

Just incase you have a faulty Fuel Cut Relay. Do the check previously mentioned regarding removing the Fuel Cut Relay and get back to us.

 

 

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Bad fuel cut relay. Did the jumper wire trick you mentioned early and it primed. When I was testing the relays A few days ago I must have been doing it wrong. Thanks for all of he help. Would it be alright if I temporarily left the jumper wire in until the new relay comes in the mail or would that burn up the pump. Nice weather and I just want to take a quick ride

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21 minutes ago, Easyrider said:

Bad fuel cut relay. Did the jumper wire trick you mentioned early and it primed. When I was testing the relays A few days ago I must have been doing it wrong. Thanks for all of he help. Would it be alright if I temporarily left the jumper wire in until the new relay comes in the mail or would that burn up the pump. Nice weather and I just want to take a quick ride

At last, well done. Don't leave the jumper in.

Just locate your High Beam Relay. Take that and place it in the Fuel Cut Relay position.

Try it and get back to us. 

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Dam thought I had it. Tried the headlight relay in its place and I didn’t work. Only works when I use the paper clip trick. Really thought it was just a bad relay but I took it off the bike and used a 9v battery On it and I can hear it click. Is the bank angle sensor not allowing it to close the circuit. 

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On 5/23/2020 at 11:27 AM, Easyrider said:

Dam thought I had it. Tried the headlight relay in its place and I didn’t work. Only works when I use the paper clip trick. Really thought it was just a bad relay but I took it off the bike and used a 9v battery On it and I can hear it click. Is the bank angle sensor not allowing it to close the circuit. 

M8. If you look at the drawing supplied you are only concerned with the top RH side. You should be able to see that if you have 12v at the Black/White wires of the Fuel Cut Relay that means the Engine Stop Relay is energized meaning the Bank Angle Sensor is working. Your "paper clip trick" would NOT work if the Bank Angle Sensor was faulty.

 

You seem to have established a problem at the FCR relay base connections!

 

Just to be sure, with Ignition to ON, Kill Switch to RUN, FCR removed, do you have solid 12v at BOTH Black/White wires at the FCR base? (Black meter lead to a KNOWN GOOD GROUND Or the Battery Neg terminal)

 

Have a GOOD look at the Fuel Cut Relay Base. Are all the connections Good?  Is the wiring Good?  Is the relay base connectors making Good contact with the Relay contacts? Do any of the spade connections on the relay base look wide/spread? Any evidence of heat stressed connectors? Have a good look at your original FCR are there any signs of corrosion or heat stress to any of the pins?

Do you see anything like the attached photos for the relay and relay base?

 

The "Paper clip trick" is purely acting as the relay contacts being energised closed, transferring 12v power from the Black/White wire to the Fuel Pump Brown wire. This confirms the continuity of the Brown wire to the Fuel Pump and your Green Fuel Pump wire is properly Grounded.

It only leaves the FCR Relay base connections that can cause your problem!

 

Keep us posted with what you find - Just as keen as you are to get your bike sorted.

 

P.S. For Info - Just hearing a Relay Click is not a conclusive test that the relay is OK. It still could have high resistance contacts. It is just an audible test to confirm the relay coil is being powered correctly. 

 

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