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Fuel pump won't shut off and no spark.


klrtovfr

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2002 VFR

Left radiator started leaking from the fan rubbing it. I pulled that off and got that repaired only disconnecting the fan control switch and fan wires. I put it back together and now the fuel pump doesn't stop pumping after turning the ignition on. We checked voltages and grounds for shorts and tested for resistance before and after the fuel cut relay. Everything seems to check out which pointed to the ECU sending the ground to the fuel cut relay but not pulling it. We then put my ecu in my friends 2004 VFR and it primed just like normal. We are kind of stuck at this point and don't know what else to check that would cause the ECU not to switch the fuel off. I am also getting no spark although it did fire up for a second but did not continue running. The pulse generator seemed to be working. Has anyone had this issue or have something I should check? The only thing we had found was that the stator to regulator connector was melted but that shouldn't be related and we temporarily hooked them up without the connector.

 

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Do as Kev said. You could use either the Hi or Lo beam headlight relays, (think they are all the same type) to replace the Fuel Cut relay. Also, when you fitted your ECU to your friends bike, did you run the bike? Or did you just switch on to verify the fuel pump operation?

Good Luck. Keep us posted.

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Well haven't switched out relay yet. It actually started working correctly once I put the ECU back into my bike. Started up and ran good. I decided to add additional power, ground and monitor wire to the stator. After that it would not stop priming again. I took the ecu grey connector off and slowly seated back onto the ECU with the ignition on and it started working again. Started it up a few times so decided to run into town for fuel and once fueled up it failed again and reseating the grey connector did nothing. What I'm trying to figure out is what inputs the ECU needs in order to switch the ground signal off on the fuel cut. I get no spark when it's not working so it's also killing that signal as well. 

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The 2 sec fuel prime is a switch on function of the ECU. From memory once the ECU sees crank or cam pulses the Fuel Pump runs continuously. The only other logic input that will kill the ignition and fuel pump is the safety logic of In gear/side stand down. The engine Kill Switch OR Bank Angle Sensor will remove 12v power from, Injectors, Spark Coils and Fuel Pump.

 

The only way the Fuel Pump will run continuously (at Ignition switch On) is either a faulty continuous ground supplied by the ECU, sticking relay contacts of the Fuel Cut Relay, a 12v short across the relay contacts perhaps at the relay base, or the energising ground wire (from the ECU) is shorted to frame/ground.

 

Think you should firstly, as suggested, isolate the Fuel Cut relay by replacement, see what happens.

All seems a bit strange that this occurred just after pulling the Fan/Thermo switch plug!

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On ‎6‎/‎11‎/‎2018 at 7:13 PM, Grum said:

Do as Kev said. You could use either the Hi or Lo beam headlight relays, (think they are all the same type) to replace the Fuel Cut relay. Also, when you fitted your ECU to your friends bike, did you run the bike? Or did you just switch on to verify the fuel pump operation?

Good Luck. Keep us posted.

Hooked it up to an '04 to verify fuel pump operation, and started it multiple times. Fuel pump ran and shut off when key was turned on, then started and ran fine.

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If I remember correctly, on klrtovfr's bike, with the fuel cut relay removed, the ecu provided ground to the connector once the key was turned on. It never cut the ground after the 2 second prime timer. That makes me think the fuel cut relay is not what is sticking.

That pin on the connector had no continuity to ground until the key was turned on. This makes me think there is not a short on the switched ground wire in the fuel cut relay connector.

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Swapped relay from headlight to fuel cut and get the same result

First one was on the brown wire. The last video is correct. That is what the ground signal looks like backprobed on the ECU connector to the other end of brown/black wire. This is with the relay connected. Sorry trying to post this from my phone and messed it up and can't delete the previous video

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47 minutes ago, klrtovfr said:

 

Swapped relay from headlight to fuel cut and get the same result. Here is what the ground signal looks like backprobed on the ECU connector to the other end of brown/black wire. This is with the relay connected. Without it the brown/black will just read 000.0 ohms which should mean the wire is good to the ecu. Checking resistance from negative battery terminal to relay side of brown/black wire reads 3.2ohms with ignition off and 57.5ohms when on

 O.K you've confirmed continuity of the ECU switch wire the Br/Bl wire. Try this - With your meter set to volts and your red probe to the positive of your battery, place your black meter probe on the Br/Bl wire at the Relay. You should be seeing near Zero volts, turn On your Ignition you should see 12v appear for the 2 sec Fuel Prime period then the volts should drop back to near zero. Let's know your results.

If you are seeing 12v all the time then the switch Ground wire Br/Bi has picked up a ground from somewhere, an intermittent short perhaps. 

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I'm seeing 12 volts with or without ignition with relay connected. Without relay it is .374v ignition off and 12v with ignition on. It never drops back to near 0 after 2 seconds whether relay is in or not

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26 minutes ago, klrtovfr said:

I'm seeing 12 volts with or without ignition

Then that's why your relay is permanently energised once your ignition is On.

Sounds like somewhere there is a short to ground on your ECU switch wire.

Try having your meter connected measuring the volts and start moving wires around all the way back to the ECU, see if this removes the 12v. You may find the short that way.

Failing that, you could do a wire By-pass. Cut the Br/Bl wire close to the ECU and the Relay base, now solder or crimp a new wire at the relay and run it back to the ECU. If you are soldering make sure you insulate your joins by a sleeve. Good Luck.

 

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I disconnected the left side blue connector and voltage dropped. I plugged it back in and voltage goes back up. I also unplugged the left side clear 6 pin connector behind radiator one wire being for the coolant temp sensor. I still have 12 volts all the time but it is now cutting the voltage correctly and fuel pump turns off after 2 seconds

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Is it supposed to see ground with ignition off? What it's  doing now with red probe on positive terminal and black probe at ECU is it's 12 volts with ignition off. When I turn ignition on. For a split second it cuts voltage and I can hear the relay click then imediately goes back to 12v for 2 seconds then drops back to near 0

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23 minutes ago, klrtovfr said:

Is it supposed to see ground with ignition off? What it's  doing now with red probe on positive terminal and black probe at ECU is it's 12 volts with ignition off. When I turn ignition on. For a split second it cuts voltage and I can hear the relay click then imediately goes back to 12v for 2 seconds then drops back to near 0

That sounds normal, without knowing the internals of the ECU, the ground may well be there prior to switch On so if that was the case you would measure 12v. But because there is NO 12v supply on the other side of the Relay coil there is NO relay action.

So, at switch ON you should still see the 12v for the duration of Fuel Prime 2 secs, THEN the ECU should remove the ground turning Off the Relay and your voltage should drop back to zero.

So are you saying it's working normal while you have that 6pin plug disconnected!!!!!

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The 6 pin doesn't seem to matter plugged in or not right now. I cut and temporarily jumpedfrom ECU to relay and it's still showing 12v ignition off and is still working correctly. I still don't know where the short was because it was always showing 12v ignition off before it started working again

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I think we can ignore the 6 pin connector, the starter would not work with that unplugged which I believe it has the neutral wire, oil pressure and side stand stand switch wires

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11 minutes ago, klrtovfr said:

The 6 pin doesn't seem to matter plugged in or not right now. I cut and temporarily jumpedfrom ECU to relay and it's still showing 12v ignition off and is still working correctly. I still don't know where the short was because it was always showing 12v ignition off before it started working again

O.K that's great. Don't worry that you are seeing 12v on this wire measured between the battery pos and the Bi/Bl wire with ignition OFF as I said it may well be grounded through the ECU until things are powered up.

So with the original Bi/Bl wire OUT of the system and you have your bypass wire from the Relay to ECU. Is everything NORMAL? Hopefully this has solved your issue, fingers crossed.:wacko:

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4 minutes ago, klrtovfr said:

I think we can ignore the 6 pin connector, the starter would not work with that unplugged which I believe it has the neutral wire, oil pressure and side stand stand switch wires

Correct - It sure does.

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Yes, for now it is working. Of course I won't know if it is fixed until I run it for a few test rides. It doesn't affect it at all when it is running and riding around but as soon as I shut it off and then try to start it is when it will show up.

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9 minutes ago, klrtovfr said:

Yes, for now it is working. Of course I won't know if it is fixed until I run it for a few test rides. It doesn't affect it at all when it is running and riding around but as soon as I shut it off and then try to start it is when it will show up.

 

Excellent, now make your new wire permanent, insulate your joins and give your bike plenty of starts and stops, then a good test ride. Keep us posted on how it goes. As for the other issue you mentioned regards No spark, let's wait and see!

Good Luck.

Cheers.:beer:

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I got resistance on the cut wire on one side of the blue connector. It looks like it was shorting a the pin with the white/black wire pin next to it which the schematic doesn't show correctly as the white black wire is shown on the opposite side of the blue connector and come from the bank angle sensor going to the right side fuse box. It seems the fuse should have blown if that's where it was shorting

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Well. I was hoping that was it, but it stopped working again and that's with the br/bl wire bypass. With grey connector disconnected from ECU and checking resistance on the br/bl pin ECU side, ignition off it's 2.5kohm, ignition on it goes straight to 0.000 and stays there. I'm thinking that wh/bl wire at the blue connector if it was shorting would have fried the ecu if it was not blowing a fuse

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5 hours ago, klrtovfr said:

Well. I was hoping that was it, but it stopped working again and that's with the br/bl wire bypass. With grey connector disconnected from ECU and checking resistance on the br/bl pin ECU side, ignition off it's 2.5kohm, ignition on it goes straight to 0.000 and stays there. I'm thinking that wh/bl wire at the blue connector if it was shorting would have fried the ecu if it was not blowing a fuse

O.k. Looks  like you have determined the ECU is wrongly providing a ground for the relay intermittently. Perhaps that short you found has damaged the ECU somehow. Agree that if the main 12v for the Bank Angle Sensor is solidly grounded you should blow a fuse, but by shorting through a ground output from the ECU who knows what might happen within the ECU. Note - Removing the Grey connector also removes the main 12v (B12) from the ECU so Ignition ON the ECU should be dead!

Think you should again give your ECU a really good run on your friends bike. You are definetly at a point where you need to verify the ECU is perfectly O.K - Or not!

Also make sure all the supply 12v and grounds for the ECU are good.

 

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Still wasn't working this morning. But I was playing with the kill switch and it started working again. The resistance reading at the ECU is the same as it was when it was not working.

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Have discounted the Kill Switch as this will inhibit your starter from cranking and kill the Engine Stop relay which in turn removes all power from the Fuel Pump, ECU, Igniters and Injectors. You don't have these issues.

So perhaps simply flicking the kill switch is just resetting the ECU momentary till the fault returns!

 

Have you done the ECU power and ground check yet? Make sure on the grey plug of the ECU the B1, B2, B14 and B26 are solid grounds use your meter low ohms check to ground, ignition to Off.

 

With ignition On. Make sure you have a solid 12v at B12. Leave your meter in this position and establish wether this voltage disappears when the fault condition is present, an intermittent loss of 12v at B12 could cause your symptoms.

 

Have a VERY close look at the wiring of the two ECU connectors, check that no pins or sockets retracted, no loose wires, no shorts, all sockets and pins look good etc. 

 

With ignition on gently flex the wires at the back of the ECU see if this induces or inhibits the fault condition.

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