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Discussion Starter · #1 ·
I have a 2008 Daytona 675 that I bought with a running issue. I have it down to no fuel now and I'm not sure why. The bike turns over, fuel pump primes, coils spark, everything except the injectors won't prime. I took a spare harness and cut off an injector wire and hooked it to one of the injectors and directly connected it to a battery and it sprayed. So I have since checked the continuity from the ECU to the injectors and the injectors to the engine management system main relay and everything tested fine. Any ideas? I'm at a loss on this. I do have a spare ECU from a known good bike and it has the same results when hooked up. The CPS tested fine and I have a Rick's here as well that also got the same results when installed. Thank you.
 

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Just a shot in the dark, but could you have a short in the harness somewhere? Continuity would still check out, but the injector might not see the right voltage if its shorted to ground. I've read through your post a couple times and that seems to be about the only thing I can come up with.

Good luck!
 

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Discussion Starter · #3 ·
Just a shot in the dark, but could you have a short in the harness somewhere? Continuity would still check out, but the injector might not see the right voltage if its shorted to ground. I've read through your post a couple times and that seems to be about the only thing I can come up with.

Good luck!
Thanks for the feedback. I initially assumed that it was a short in the harness, but wasn't sure how to fully narrow that down as this is the second harness I've had in it. I did purchase another harness today that is supposedly "mint" with relays etc. so I'll swap again and report back. This has been a real head scratcher for me and I hate electrical issues :smilielol5:
 

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Discussion Starter · #4 ·
Swapped out the wiring harness and still no fuel through the injectors. I direct connected a battery to an injector again and it sprayed. I'm scratching my head on this one. Any parts that are not on the harness that could cause this? What about if the incorrect map is on the ECU through TuneECU? Does anyone know what map I should have installed on a 2008 675 Daytona that is 100% OEM? The files are confusing. Thanks.
 

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Discussion Starter · #7 ·
The gauges appear to function perfectly, but any chance something related to those could be an issue with no fuel spraying? I'm trying to narrow it down and have replaced almost everything at least once except those and the voltage regulator (which I assume would have nothing to do with this issue).
 

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Unplug an injector, key on. Grab a digital multimeter. Put the ground wire of the meter into the engine, clean metal. Use the positive dmm wire and probe the inside of the injector plug. DO NOT JAM THE DMM PROBE INTO THE INJECTOR CONNECTOR YOU CAN PERMANENTLY SPREAD THE PINS AND F THE CONNECTOR. PROBE LIGHTLY! THD PROPER WAY WOULD BE TO PROBE FROM THE WIRE SIDE, USING PINS/NEEDLES STUCK DOWN BETWEEN THE WIRE AND CONNECTOR SEAL (BACK PROBING)One WIRe should be 12v b+ with key on. The other wire should be dead. But will trigger the ground from the ecm when it wants to fire the injector.

We did this so we can find a direction to head. If there is no b+ in the injector harness with the key on, you have a power problem. If there is b+ in the injector plug, we have a control problem. A power problem could be a bad relay or fuse, pinched wire, etc. A control problem could be a smoked injector driver in the ecm, pinched wire, bad crank sensor, or anything else that tells the ecm when to light up the trigger wire (ground) for the injector. All efi systems trigger grounds, NOT b+ to activate things. It keeps high current and electrical noise from messing with the ecm.

Am 20 year auto tech. Report back with findings

Sent from my Pixel XL using Tapatalk
 

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Discussion Starter · #10 ·
Unplug an injector, key on. Grab a digital multimeter. Put the ground wire of the meter into the engine, clean metal. Use the positive dmm wire and probe the inside of the injector plug. DO NOT JAM THE DMM PROBE INTO THE INJECTOR CONNECTOR YOU CAN PERMANENTLY SPREAD THE PINS AND F THE CONNECTOR. PROBE LIGHTLY! THD PROPER WAY WOULD BE TO PROBE FROM THE WIRE SIDE, USING PINS/NEEDLES STUCK DOWN BETWEEN THE WIRE AND CONNECTOR SEAL (BACK PROBING)One WIRe should be 12v b+ with key on. The other wire should be dead. But will trigger the ground from the ecm when it wants to fire the injector.

We did this so we can find a direction to head. If there is no b+ in the injector harness with the key on, you have a power problem. If there is b+ in the injector plug, we have a control problem. A power problem could be a bad relay or fuse, pinched wire, etc. A control problem could be a smoked injector driver in the ecm, pinched wire, bad crank sensor, or anything else that tells the ecm when to light up the trigger wire (ground) for the injector. All efi systems trigger grounds, NOT b+ to activate things. It keeps high current and electrical noise from messing with the ecm.

Am 20 year auto tech. Report back with findings

Sent from my Pixel XL using Tapatalk
Thanks for the reply. I pulled one wire and had 13v on one and 6.9v on the other, the 6.9v would change and settle back on 6.9v.
 

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Thanks for the reply. I pulled one wire and had 13v on one and 6.9v on the other, the 6.9v would change and settle back on 6.9v.
6.9v is extremely abnormal. I suspect a short to B+ somewhere in the harness, or faulty ecm. Next step would be to completely disconnect the wiring harness from everything, set DMM to ohms and measure resistance between the b+ battery cable which should be disconnect from the battery, and whichever pin in the injector harness had 6.9v. other option is to follow the 6.9v wire back to the ecm. Cut the wire an inch away from the ecm connector, power it all up and measure the voltage coming directly out of the ecm on the snipped wire. If 6.9v is gone, you have a short somewhere

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me too having similar issue but there is no short in my harness
12v on the pin 1 and other are zero.. ecu signal deliver pulse when i cranked and conect to isciloscope
 
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