[Rnd]

I'll check that now and we can ground the injector for a split second and it will pulse and then machine will turn over and fire but won't stay running. Burns what fuel was sprayed then dies out. But there is 12 volts constant power going to the injector key on or off now. And now with noid light no signal sending a pulse to injector.

 

[Rnd]

There is twelve volts with key on at a8. I have another good ecu coming from a running 800 to try again its like it's got no signal telling it when or to even pulse unless u do it manually.

 

[RangerRider_1]

There is twelve volts with key on at a8. I have another good ecu coming from a running 800 to try again its like it's got no signal telling it when or to even pulse unless u do it manually.
The way it works is 12v is constantly supplied to the injector. The ecm controls the ground side.

Is it 12v at the injector plug with key on?

The way it works is 12v is constantly supplied to the injector. The ecm controls the ground side. Check continuity between the injector plug and the plug on the ecm. Look at the service manual and trace the black (mag side) and white (pto side) back to the ecm plug.

When does it fall to 3v on the injector?

 

[RangerRider_1]

Another thing... if you have factory injectors the plug on the injector is set in epoxy and you will damage the injector if you try to get it off there. All you can do is unplug it from the harness.

 

[Rnd]

I have traced those wires and have continuity thru wire and twelve volts constantly. As you crank it drops to 10 volts. But if u ground it out it will pulse the injector. Also I did check back to the ecu and the voltage is there. I feel as the it's down to a wiring issue that's not telling injector to pulse or it is the ecu. But I removed ecu and put in a working ranger and it fired right up no issues.

 

[Rnd]

I have replaced the injectors and harnesses on machine.

 

[RangerRider_1]

I have replaced the injectors and harnesses on machine.

Understand, but you still need to check the continuity to see if that's causing the issue. There are other reasons "why" its doing this, but this is one of them.

 

[Rnd]

I'll go back and recheck all the wiring for continuity to the ecu connector from the injectors. Following the wiring diagram. If I jump the wire from the ecu connector to the injector and eliminate 90 percent of the wire minus the plug in the ecu connector and have continuity wouldn't that correct that as an issue. Aswell is there any other items that can give the ecu the signal to tell it when to pulse?

 

[RangerRider_1]

I'll go back and recheck all the wiring for continuity to the ecu connector from the injectors. Following the wiring diagram. If I jump the wire from the ecu connector to the injector and eliminate 90 percent of the wire minus the plug in the ecu connector and have continuity wouldn't that correct that as an issue. Aswell is there any other items that can give the ecu the signal to tell it when to pulse?

You don't have to rewire anything. All you have to do is use an ohm meter and test ohms between the injector plug and the appropriate place on the ecm plug. You just need to make sure the wire there is good

 

[Rnd]

Will check that first thing in morning and go from there. If it does have a good connection and is still not pulsing what could be a possible cause. Just so I have more to check just in case. I've even called polaris tech to help and I've gotten more from here than them.

 

[RangerRider_1]

Will check that first thing in morning and go from there. If it does have a good connection and is still not pulsing what could be a possible cause. Just so I have more to check just in case. I've even called polaris tech to help and I've gotten more from here than them.

If the continuity checks good,, it could be a short somewhere else in the harness. I had a similar issue and mine was chaffed wires of the TPS, IAC and IAC bundle before the main harness.
With the ecu unplugged, also check for continuity between injector plug and the frame. This will make sure the ground wire is not shorted out somewhere in the harness.

 

[Rnd]

Okay I'll add that if the first test goes good and update tomorow thanks

 

[RangerRider_1]

Okay I'll add that if the first test goes good and update tomorow thanks

Do both tests for each injector ground wire regardless.

 

[RangerRider_1]

I have traced ...
.
.
But I removed ecu and put in a working ranger and it fired right up no issues.

I was re-reading your posts and just saw this.
If you replaced the ecu module with a known good unit and it runs with it and no other changes... that pretty much nails it being a bad ecu in your Ranger.

The only other thing that might cause this would be a bad ecu plug. Maybe you had it "just right" when you connected up the "good" ecu and when you put yours back in, it wasn't making a good connection.

 

[jdavidson]

I have traced those wires and have continuity thru wire and twelve volts constantly. As you crank it drops to 10 volts. But if u ground it out it will pulse the injector. Also I did check back to the ecu and the voltage is there. I feel as the it's down to a wiring issue that's not telling injector to pulse or it is the ecu. But I removed ecu and put in a working ranger and it fired right up no issues.

I am confused by this comment? are you stating that you took YOUR Ecm out and put it into a ranger that runs, and that it ran just fine? or are you saying that you took a KNOWN RUNNING ECM out of a Known Running Ranger, and put that ECM into your non running unit, and now it runs fine?