[rce1]

My 09 rhino 700 FI starts and runs for a while then dies. I can hear the pump prime but it won’t start. After it sits for a while it starts , might run for a while but then dies Replaced relays and it is getting a good spark. Any ideas ?

 

[sandbuster]

Fuel filter? If you have replaced the filter then do a fuel flow test. If you can, remove the fuel line to the throttle body. Disable the ignition to eliminate arcin & sparkin, then have someone turn the key on and observe for a good strong squirt of fuel. Pump should engage with key on for 2-3 seconds giving you ample time to check fuel flow. If flow is weak to non existent and you did change the filter then start back tracking the fuel lines all the way to the tank. If all looks good then next step would be to check for plugged sock on pick-up tube in the fuel tank. At least I'm pretty sure they have socks on them as I recall seeing this advice previously on this forum. Good luck.

 

[HighDezRhino]

If it runs fine and dies after a while, you might check to ensure the fuel tank is venting. A clogged vent line will create a vacuum situation where after a while the fuel can no longer make it to the throttle body. Try removing the fuel cap after it dies to see if it makes a difference.

 

[sandbuster]

Good thought High Des - I forgot about that one.

 

[rce1]

Fuel filter? If you have replaced the filter then do a fuel flow test. If you can, remove the fuel line to the throttle body. Disable the ignition to eliminate arcin & sparkin, then have someone turn the key on and observe for a good strong squirt of fuel. Pump should engage with key on for 2-3 seconds giving you ample time to check fuel flow. If flow is weak to non existent and you did change the filter then start back tracking the fuel lines all the way to the tank. If all looks good then next step would be to check for plugged sock on pick-up tube in the fuel tank. At least I'm pretty sure they have socks on them as I recall seeing this advice previously on this forum. Good luck.

Thanks will try that

 

[rce1]

Thanks will try that

Thanks will try that

Found the problem. It was the ECU

 

[sandbuster]

That's unusual but obviously it happens. How did you troubleshoot it - swap it out with a known good one?

 

[rce1]

That's unusual but obviously it happens. How did you troubleshoot it - swap it out with a known good one?

All fuel lines and wiring were good. bypassed the fuel pump relay and it runs fine. new relays, even switched them around to make sure I didnt get a bad one,fuses are good,relay good,pumps works fine, service manual says if all these are good the only thing left is ECU. I ordered a tuneable one , we will see if thats it. Yamaha dealer said they couldnt test it. Only option was to try a new one.

 

[sandbuster]

Sounds like you covered all the bases.

 

[HighDezRhino]

Did the new ECU fix the problem?