[Dakota_spencer]

I have an 07 700 and the fuel pump is not getting power when cranking. It primes when I turn the key off and on but I probed the connector and it doesn't get any power when cranking only when priming.
If I start at and hold the rpms up its will stay running but as soon as you slow down it shuts right off and will only start if you crank the engine while the pump is priming.


Not sure where to start, thanks in advance.

 

[Dakota_spencer]

Update it is getting power when cranking now. But well only idle for a few seconds and die unless I give it has. Tps??

 

[Dakota_spencer]

Update 2, the tps starts at .66 and peaks at 3.83 so its fine right? Im stumped

 

[Dakota_spencer]

Also just found out it has no spark either. If I turn the key on and crank it it only has spark until the pump stops priming. And I have a jump box on it and when I unhook it it gets spark back but its too dead to start with the plug in. And the pump works when cranking without the jump box but well still only fun for 5 seconds. Im giving up until I have some answers because I'm out of ideas. Thanks in advance

 

[morphrider]

Possible battery issue not providing enough power. Let the battery charge over night, then check voltage before starting. Throw a new plug in there for kicks as well.

 

[Dakota_spencer]

Possible battery issue not providing enough power. Let the battery charge over night, then check voltage before starting. Throw a new plug in there for kicks as well.

But why does it lose spark with the jump box? Also I took it out and it ran great for about an hour and then started doing this. Its rideable if you keep the rpms up but dies if you slow down and fires right back up but only for a few seconds if you dont take off.

 

[sandman89]

My guess would be put a new battery in it. If everything works without the jump box it makes sense that this would be the problem. Maybe the battery is grounding internally when you add the extra amps from the jump box.

 

[4stroker4life]

Update 2, the tps starts at .66 and peaks at 3.83 so its fine right? Im stumped

I dont know the specs off the top of my head, but you need to make sure the voltage increases smoothly as throttle is applied, not sporadically

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[4stroker4life]

Also, do you have fresh gas in it? What kind of fuel are you using?

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[Dakota_spencer]

Also, do you have fresh gas in it? What kind of fuel are you using?

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Yes its fresh 91. Im pretty sure its an electronic problem because it happens they same every time I start it. Runs good for 5 seconds looses spark and dies. But what could be making it lose spark?

 

[Sixpack577]

I would check that all the grounds are clean and tight.
Eliminate the simple things, as bad ground can cause all types of gremlins.
Otherwise it would be unusual for a stator, or coil to work intermittenly.
I would unplug and plug connectors in the harness, and the ecu plugs.
Sometimes pins get pushed back or get dirt stuck in the dielectric grease.

 

[Sixpack577]

Also, you wouldn't happen to know anyone with an 06-08 you could swap the CDI/ECU with do you?

 

[Dakota_spencer]

Also, you wouldn't happen to know anyone with an 06-08 you could swap the CDI/ECU with do you?

Yeah I do, just not for a couple weeks. I will tear into it more this weekend and go over all the connections if that doesn't work all have to grab that ecu from my friend when I can.

Its just so weird because it runs perfect but only for 5 or 10 seconds then it seems like it cuts spark
And its very repeatable

 

[Dakota_spencer]

Also It currently has a cheep Chinese fuel pump in it could that be causing some kind of issue in the ecu?

 

[Sixpack577]

.

 

[Sixpack577]

Yes, that's a possibility also.
I wouldn't say the pump was effecting the ecu, but the pump itself could be the problem.

 

[Dakota_spencer]

I will have to swap it with my friends as well, just that $400 Yamaha price tag really hurts

 

[4stroker4life]

I will have to swap it with my friends as well, just that $400 Yamaha price tag really hurts

What kind did you buy?

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[Dakota_spencer]

What kind did you buy?

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This one