06 switch 900 no start

dman142 · Feb 11, 2016

So to recap:
1. Replaced the entire fuel delivery system so far.
Pump assembly and injectors.
2. Will only start with a cap of gas poured into the cylinder.
3. It will run fine after that.
4. Indicates good charging on the mfd.

the ecu is still flashed to a htg 975. Problem here? Can't see how that's going to fix the issue. Spark is great. Fully rebuilt motor.

The injectors are not firing on their own when the recoil is pulled. Once gas hits the cylinders, it's fine.

Ecu issue or stator? Flywheel looked fine and no glue issues or separation.
There's not much left to replace.
Thanks.

dman142 · Feb 12, 2016

I think for some reason it's not getting the 16v supply to open the injectors when the recoil is used. Generates enough when running however.
Checked the stator and flywheel. The inner ring on the flywheel let go but didn't cut the wires as far as I can tell. I'll glue back into place.
Anyone think that's the problem?
D

guidoxpress · Feb 12, 2016

The stator has green and..yellow(?) wires strictly for the injector pulse circuit. I would imagine when you ohm'd the stator you did this as well?

Also..this was an issue I caught myself once..the gap on the stator sensors could be off.

I had one get bumped up and the gap from the sensor to the flywheel key was too big. Just a thought?

Sent from my iPhone using Tapatalk

dman142 · Feb 13, 2016

I ohmed the stator blue/yellow to blue /yellow and come up with 2.5 ohms. This is what the service manual says.
Fuel pressure is holding good. May not have been the problem all along.
Thoughts on ecu?

guidoxpress · Feb 13, 2016

dman142 said:
Thoughts on ecu?

Worth a shot, Ecus create all kinds of issues and urs isn't even programmed for your port timing, compression, fuel curve ect..might as well try that

Sent from my iPhone using Tapatalk

TriumphoverU · Feb 15, 2016

Just for giggles, unplug the chassis relay and see if it will start without pouring gas down the cylinders.

dman142 · Feb 15, 2016

Where is the chassis relay? From what I read, I don't have any issues with the gauges or power. I have a pressure gauge on the rail and can get 100+ psi within 3 pulls.
I'm about to tear the whole thing apart. Getting really frustrated.
Ordered a used Ecu today. After that, everything that attaches to the motor will have been replaced. Only thing left is the stator.

Fuel pump-2 of them
Injectors
Ecu

Motor: rebuilt from crank up including new case, cylinders, pistons, etc.

Cerialsledder · Feb 16, 2016

dman142 said:
Where is the chassis relay? From what I read, I don't have any issues with the gauges or power. I have a pressure gauge on the rail and can get 100+ psi within 3 pulls.
I'm about to tear the whole thing apart. Getting really frustrated.
Ordered a used Ecu today. After that, everything that attaches to the motor will have been replaced. Only thing left is the stator.

Fuel pump-2 of them
Injectors
Ecu

Motor: rebuilt from crank up including new case, cylinders, pistons, etc.

Chassis relay is between the chassis stiffener and mag side cover on the motor. Look for it taped to the wiring harness.

dman142 · Feb 16, 2016

Not the chassis relay. I have an Ecu coming.
Anyone have a stator? Might as well just replace everything I guess...

dman142 · Feb 20, 2016

Not ecm.....still the same. I have to be missing something.

dman142 · Feb 24, 2016

Not the stator either. Almost seems like after I did the Ecu, spark got weaker too. I did glue the ring in the flywheel also. Can the glue interfere with the ability to function properly? Expoxy type glue.

Only thing left is the coils. At that point, everything else has been replaced.

Otherwise, I am stumped.

dman142 · Feb 24, 2016

Any other suggestions ? If nothing else, another 900 goes to the big parts heaven in the sky within a month or so.

Anyone have a contact in northern wi that knows cfi sleds well enough to look at it?
Darin

dman142 · Feb 25, 2016

Capacitor tested good and holds voltage.

dman142 · Feb 26, 2016

Now I don't have spark. It fires a single spark then nothing. I changed out the Ecu and stator with no change in this condition. I have coils coming. Even changed out the tps wiring harness.
Then if there's no spark, I'm 100% out of ideas.

The fuel pump does run when I pull it over so I know there's power.

Disconnected the bar switches and key. Checked grounds, cleaned connectors, disconnected hood wiring, etc.

So far replaced:
Ecu
Stator
Injectors
Fuel pump

Original problem was not running on the mag cylinder.
Please respond with ANY suggestions.

guidoxpress · Feb 27, 2016

Well looking back from the beginning. Looks like the only major component in the ignition state you haven't replaced is the flywheel. However u said the ring was reglued..if u out too much glue I can (I assume) interfere with the current flow?!?!?

Maybe someone has a flywheel to loan and try this?

Sent from my iPhone using Tapatalk

guidoxpress · Feb 27, 2016

I knw we have talked about this, but found this reply to someone having a cylinder losing fuel (but I bet Uve seen it and every other thread on here lol)

I wanted to add a response to this thread, as I was having the same exact symptoms as described above on my 05' 900. After laboring through most of the trial and error checks described in this thread, and after completely pulling the motor, sending my injectors in for cleaning and testing and finally deciding to replace the injectors completely (just to be sure). I put it all back together and still had the same issue. After hours of additional research on the web, I revisited this thread and this post jumped out at me. Sure enough, the pins in the mag side injector plug were not seated properly and were breaking connection after the engine warmed up. A very simple problem that cost a lot of time, money and patience. Gook luck!

Sent from my iPhone using Tapatalk

dman142 · Feb 28, 2016

So I had my hopes up for a few minutes. Had really good spark then went to put the Ecu back on the mounts, tested again. Nothing. We all know how the wires are packed in there, I wonder if there isn't a break in a wire someplace in the harness? It's nearly impossible to replicate though since it could be a single strand of wire making connection, then breaking connection when moved.

Luckily, the snow is on its way out now in N Wisconsin so I can put this away until fall. Still have my edge 800 if we get a late snow like we usually do.

dman142 · Feb 29, 2016

I tested each injector while they are still in the sled. Only one that was suspect was the lower mag injector. I couldn't get it to open at first but of course when I went back to check it again it would open and spray. It would make sense since that is the injector that controls that side at startup and idle.

Spark problem was self healing for the time being.

dman142 · Feb 29, 2016

So my next question: should the injectors fire gas when I'm turning it over? I'm going to hook up a set of injectors in the sled, but not mount them in the case/cylinder. I could only imagine, the lower injectors should fire at least a little in order for the engine to start?
I'm going to be turning it over with my drill on the primary bolt without the plugs in. It spins it faster than the recoil does. That's how I test for spark too.

dman142 · Feb 29, 2016

Well, it's fixed. But have not run it outside yet.
My question is there a connector that pigtails into the lower injectors? It has 6 wires going to a white connector...pic attached.

The mag injector was not firing but I took the extra wires and pigtail out of the loop and first pull it started.
I made my own injector testing harness and found the issue of it not firing when I turned it over.
So now I have every electrical part as backups.

06 switch 900 no start

Well-known member

Well-known member

SnoWest Badge Maker

Well-known member

Well-known member

Similar threads