Getting spark to only one cylinder

[henks]

Yes, the one not working worked when hooked up to the other cylinder wire harness. And the one that was working on the other harness did not work on the original 'no spark' harness.

Hope that makes sense.

 

[cannondale27]

Makes sense. So when you say not working do you mean you had the coils out of motor with a plug in them grounded and saw or didnt see spark? Or did you start the engine and determine which cylinder was and wasnt firing by feeling the exhaust manifolds for heat or cold?

 

[henks]

Grounded the plugs and visibly checked for spark.

 

[cannondale27]

Then as long as you dont have any bent pins or bad connections about the best method would be to try swapping ECU. Sorry was hoping it was something simple.

 

[henks]

Yeah that's kind of the stage we are at now. Thanks for all the input everyone.

 

[yamahas]

I am prety sure the manual give you specs of what wires to check for continuity from the coil to the ECU. If you have not checked this I can try to find it when I get home if no one else beats me to it.

 

[henks]

We checked continuity from the coils to the ECU. Orange on one coil, Grey/Red on the other. Both coils have a solid red wire as well.

 

[yamahas]

Sounds like you've looked through the wiring diagrams and checked all the wires, could it possibly be a short? Possible to get good continuity to the ECU while still having a short to ground. I would expect a code though. See if you have a short to ground on the bad side that you don't have on the good side. Hopefully you can find an ECU to see if that fixes it before buying one.

 

[DigitalFusion]

yeah, we tested for a short to ground as well by using the test light connected to the positive on the battery.

 

[henks]

Update:

I must have a parasitic draw on the battery somewhere. Key was off and kill switch was engaged. I went to crank over the sled with a different ECU after being gone for a couple weeks, and nothing. Threw a meter on it, and had just over 7 volts. So now I'm looking to see where all the grounds are on this, to see if one might be bad or something. I was looking at the ground block TSB thread, but from what I can tell I don't have any melting on the harness at all near the yellow connector.

So as I sit here while the battery charges, any more ideas?

 

[henks]

Oh, and still not getting any codes or anything.

 

[cannondale27]

Draw could be the bad ECU. Turn off sled,Remove the wires from neg of battery and put your test light between Neg post and all wires that go to it. If it lights you have a draw.

 

[henks]

Light didn't light up but tried the meter. Original ECU showed no voltage. New (used) ECU showed voltage. So that means the original ECU is bad, and the new (used) isn't and proves there's a draw, right?

 

[cannondale27]

Right but I was expecting the opposite. So start pulling fuses till no voltage is shown. Whatever circuit that is. Is where draw is. None of this proves whether new ECU is good or bad. Just proves you have a draw.

 

[henks]

Ok. In other news, I opened up the yellow grounding block. No evidence of burning, and it looks like the update might have been done, but i only see the one lead for the negative battery terminal, contrary to what is shown in that TSB.