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Discussion Starter #1
Checked and no voltage on brown lead at #3 injector. By the schematic all injectors are fed from same wire from fuel pump relay. Have battery voltage on Bl/Y into relay but only .5V coming out on Br. Battery voltage on Bl/Y & Br/Bl so relay is tripping. Swapped relays with headlight relay(witch works)and same readings.
Any ideas ?
 

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Any signs of rodents ??? I think all the injectors ground through a gang plug (either white or orange). The gang plug is on the engine side of the frame behind and near the left forward frame stub. Any signs of contamination or burns in the plug ???

Opps ... I guess it is yellow.
 

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Discussion Starter #3 (Edited)
No sign of rodents, at least chewing, there was some old nest material under the air box but cannot find any evidence of chewing on wires. I am grounding on the battery and testing for voltage at the fuel pump relay, I do not understand why my Fluke is reading battery voltage (12.8) going into the relay but only .5 coming out. The relay works in the Low beam socket, tried three different relays and all read the same.
Cleared the FI codes, turned on and it flashed 12 thru 17(all injectors) then went back to code 14 after cycling the ign on/off.
 

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GL1800 Doctor
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No sign of rodents, at least chewing, there was some old nest material under the air box but cannot find any evidence of chewing on wires. I am grounding on the battery and testing for voltage at the fuel pump relay, I do not understand why my Fluke is reading battery voltage (12.8) going into the relay but only .5 coming out. The relay works in the Low beam socket, tried three different relays and all read the same.
Cleared the FI codes, turned on and it flashed 12 thru 17(all injectors) then went back to code 14 after cycling the ign on/off.
You need to watch the brown wire as you turn on the key. Power will only be there for a few seconds while the fuel pump runs. Then it should appear again while you are cranking the engine. Use the battery negative post for your meter’s ground. You need to monitor the black/yellow wire at the relay as well. If it drops a lot while you’re cranking the engine, you have an issue with C5. All of the injectors share this brown power wire, but they are controlled/grounded individually by the ECM on their own individual wire.
 

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Discussion Starter #5 (Edited)
Rob
I am using battery - as ground for the meter. I removed the gas tank and air box to check for chewed wires, found nothing The brown wire at the fuel pump relay only shows .5V when I first turn on the key and stays steady and no fuel pump run. The B/Y wire shows battery 12.8 with key on and drops to 11.9 while cranking. Never checked the brown while cranking but will do that once I get the air-box and gas tank back in, probably in the morning. I even tried running a jumper from +battery to the brown lead at the relay, fuel pump ran for a few seconds but still no start. What baffles me is battery voltage into the fuel pump relay but nothing out on the brown lead, tried three different relays with same result. (they all work the headlight) both leads to trip the relay show battery V and you can feel the relay trip.
 

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GL1800 Doctor
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Rob
I am using battery - as ground for the meter. I removed the gas tank and air box to check for chewed wires, found nothing The brown wire at the fuel pump relay only shows .5V when I first turn on the key and stays steady and no fuel pump run. The B/Y wire shows battery 12.8 with key on and drops to 11.9 while cranking. Never checked the brown while cranking but will do that once I get the air-box and gas tank back in, probably in the morning. I even tried running a jumper from +battery to the brown lead at the relay, fuel pump ran for a few seconds but still no start.
Ok, since the black/yellow wire stayed above 11.1V and the pump didn’t run, the ECM is failing to energize the pump relay. This means the injector codes it’s throwing are real. You need to examine C10 & C13 on each outside of the frame where the brown wire splits and runs to the injectors. #14 code would be caused by C13, it’s a 4 pin gray connector near the knee cap vent on the right side. Until you track down what is making the ECM think it’s got a bad injector, it won’t allow the pump to run or the injectors to have any power. A continuity check of the wire from the injector all the way up to the pump will help narrow it down.
 

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Discussion Starter #7
Rob
from brown at fuel pump relay to brown at C13 = 0 resistance
 

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Discussion Starter #10
0 resistance from pump relay brown to injector #3.


I have the manual open pg 22-9
 

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GL1800 Doctor
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0 resistance from pump relay brown to injector #3.


I have the manual open pg 22-9
Ok, then the only thing left is to check the continuity of the ECM side of the injectors back to the ECM. It’s doubtful that this side of the circuits would be the issue, unless a critter chewed up one of the wires. If those wires all check good, then it’s either a bad ECM or a bad injector.
 

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Discussion Starter #13
checked red/black from C13 to ECM = 0 resistance
Tried a good ECM earlier, must be the injector. will try replacing that tomorrow.


Thanks a bunch Rob
 

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GL1800 Doctor
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checked red/black from C13 to ECM = 0 resistance
Tried a good ECM earlier, must be the injector. will try replacing that tomorrow.


Thanks a bunch Rob
Before you pull it, check the resistance of it from brown to the red/black wire, then compare it to one of the others. Good luck, keep us posted.
 

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Discussion Starter #16
UPDATE
#3 injector was bad, only .3ohm and should be 11.1 - 12.3. I got it replaced with a used one that tested within spec. There was a lot of dirt in the hole when I removed the injector, got it all cleaned out with Q-tips covered with silicone. Just have to put it back together enough to start and check for codes and gas leaks. Fingers crossed !! I'll update again once I start it.
 

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GL1800 Doctor
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UPDATE
#3 injector was bad, only .3ohm and should be 11.1 - 12.3. I got it replaced with a used one that tested within spec. There was a lot of dirt in the hole when I removed the injector, got it all cleaned out with Q-tips covered with silicone. Just have to put it back together enough to start and check for codes and gas leaks. Fingers crossed !! I'll update again once I start it.
Great! Love a definitive cause. :grin2:
 

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Discussion Starter #19
Bike is back together and running like a champ, no FI codes.


Ended up cheating a little, was able to access and change the injector without removing the main fairing or the radiator, with the top shelter off and the inner fairing removed. I just removed the two bolts holding the radiator and lifted it up enough to remove the injector holder and flex the fairing enough to get my hand in there.


Thanks guys.
 
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