suzuki dt115 efi having engine miss on cylinder 3

[zhogar00]

new to this forum.
I have a 1997 wildfire 120 with a Suzuki dt115s EFI on the back.
took it out a week ago and notices it was vibrating bad, didn't sound healthy and low power, did a compression test a month ago and they have good compression.
1. checked all plugs, they all have spark. but found a miss on cylinder 3
so I crossed off plugs and wire sets off my list.
2. put new plugs in and switched coils 2 and 3 just to make sure and we still a miss on cylinder 3.
3. next on the list was injectors switched injectors 1 and 3. we still have a miss on cylinder 3. so injectors are off my list.
4. now I was starting to scratch my head and decided to check "power to the injectors". cylinders 1,2,4 all are getting 19.6 volts to the injector except for cylinder 3 its getting .2 volts.
5. took the wires from the plug and the crimp on the wires look good. unwrapped the wire and there was no cuts or anything.
6. shaved a little off of the wire from right outside the ECU to do a "ohms" test and it comes back with no resistance. so I now know the wire from the ECU to the injector plug are fine.
7. now I feel that I've narrowed it down to the ECU.

is there anything else I should check? or do you guys think that its probably the ECU? if so my ECU part number is 33920-94601. I can only find one through BOATS.net and they want $1900 for it was seeing if I can find one used but the only ones I can find are #33920-94630 would that work? its for a dt115s EFI but just a different year engine.
Thank you!

[Solarman]

Could Google your part number, with "suzuki ECU" for name, see if something pops up? Could be used, just request it came off working motor, some will guarantee it came from working motor? New they are expensive.

Good luck. Post back when able to let us know how it's going.

[redlowrey]

new to this forum.
I have a 1997 wildfire 120 with a Suzuki dt115s EFI on the back.
took it out a week ago and notices it was vibrating bad, didn't sound healthy and low power, did a compression test a month ago and they have good compression.
1. checked all plugs, they all have spark. but found a miss on cylinder 3
so I crossed off plugs and wire sets off my list.
2. put new plugs in and switched coils 2 and 3 just to make sure and we still a miss on cylinder 3.
3. next on the list was injectors switched injectors 1 and 3. we still have a miss on cylinder 3. so injectors are off my list.
4. now I was starting to scratch my head and decided to check "power to the injectors". cylinders 1,2,4 all are getting 19.6 volts to the injector except for cylinder 3 its getting .2 volts.
5. took the wires from the plug and the crimp on the wires look good. unwrapped the wire and there was no cuts or anything.
6. shaved a little off of the wire from right outside the ECU to do a "ohms" test and it comes back with no resistance. so I now know the wire from the ECU to the injector plug are fine.
7. now I feel that I've narrowed it down to the ECU.

is there anything else I should check? or do you guys think that its probably the ECU? if so my ECU part number is 33920-94601. I can only find one through BOATS.net and they want $1900 for it was seeing if I can find one used but the only ones I can find are #33920-94630 would that work? its for a dt115s EFI but just a different year engine.
Thank you!

How can you do a proper resistance check with the wiring loom still connected to the ecu, how do you know if the wiring has not gone to ground between the ecu and the injector plug, it will still show up as continuity.

[zhogar00]

How can you do a proper resistance check with the wiring loom still connected to the ecu, how do you know if the wiring has not gone to ground between the ecu and the injector plug, it will still show up as continuity.

Thank you for your responses!
you have a great point, I don't know why I over looked that. Was a little disappointed at this whole thing and probably got caught in the moment.

UPDATE: what I ended up doing was taking it to the university I study at and had a couple electrical engineering professors take a look at it. they were able to get a section of that "rubber type potting" that seals and protects the ECU circuit board off, then tested the soldering point where the wire goes into the board and showed that its not fractured. They concluded that somewhere on the board there is a fractured solder point that's causing this problem. We couldn't try to find and fix it where ever it is because of that potting sealant we more than likely would damage the board taking that stuff off than anything being fixed.
Gonna have to wait a little bit to get another, hopefully someone decides to sell a used one online and ill snag that.