2005 sportsman 700 efi

No matter what the outside temp is, when the engine has sat for ~24 hours (overnight) and i go to start it, the first attempt always fires then dies. Second attempt usually starts the engine succesfully although has failed on a few occasions. Seems to be fine once started.

Shouldnt efi fire up first try? I seem to remember it being that way a couple years ago but am not sure what changed? New plugs, uni air filter, stock machine.

 

My old truck does the same thing. I turn the key on first and sit a couple seconds,then turn to start and have to let off the key.Try again and it usually starts right up with an occasional stumble.Once it's warm it cranks up normally,runs good. Been doing this for a few years now and I know it's loosing it's prime over night. Could be the regulator bleeding down or the fuel pump itself. Both of these like your fuel pump are located in the tank. Do a pressure test first thing in the morning Just with the key on and pressure tester and see what it shows. Should be 39 psi. If less then might be a good idea to replace the pump and regulator. Several of these kits are on ebay. NEW Polaris Sportsman 500 700 800 EFI Fuel Pump X2 MV7 2004-2010 2520437 +REGLTR | eBay Something I have to address fairly soon or I might be stranded.. Plus you might want to check the inline fuel filter. Could have something to do with it also. Replaced mine though and still have to do the same starting procedure.Plus you might want to check the thumb throttle free play. If too loose the contacts may be arcing causing starting problems. Adjust the throttle cable to where you have no more than 1/8" slack. This should have the etc contacts far enough apart so they can't interfere.

 

"Do a pressure test first thing in the morning Just with the key on and pressure tester and see what it shows. Should be 39 psi." If i turn the key on iit will engage the fuel pump and put the pressure to 39, right? Shouldnt i check the pressure without turning the key on?

Should the pressure hold overnight meaning if i go check the psi in the morning without turning the key to start should it read at least 39psi?

 

Have the pressure gauge hooked up and turn the key on. Bleed any air from the pressure line and close the valve,then fuel pressure should be around 39psi +/- 3 psi. The regulator is supposed to hold this pressure. The manual doesn't say to test pressure with the key off,don't know if you can get an accurate test as the ecu kicks in the pump to prime it up initially,then will also turn off the pump after a few minutes if the key isn't turned from the on to the start position. The system is pressurized at all times,but there may be some normal bleed down over night. I'd just do what the manual says. If pressure is lower than suggested or borderline then I'd just replace the pump and the regulator as a kit.

 

Hooked up the gage. Turned the key to on. Jumped to about 40 psi and tricled down to about 37/38. Then i started it and it fired and died. Started it again and it ran, while running the gage stayed at 39/40.. psi Seems normal to me

Forgot to mention it has a new battery

Could th starter not be turning the engine over fast enough? Other things to check?

 

Then this may not be a fuel pump/regulator problem. May even be a tbap or tps sensor harness problem if it cranks and dies. Check the wiring from these sensors for any obvious abrasion plus for any soft feeling wires that may have meted internally. Even the crank sensor harness that runs under the throttle body could have a bare wire that's intermittently shorting to ground. Have a manual at least that has step by step trouble shooting guides that can help you narrow down where the problem is.Here's one for 5 bucks.2007 Polaris Sportsman 500 EFI Service Manual PDF Download

 

Very glad you brought this up, I have the exact same problem (2006 500 EFI). I do have a fuel pressure gauge, so assuming I have the correct connector, where do I access the test valve? I have the manual but it's still a bit unclear to me how to access it. Thanks. I will check over wiring as well.

Speaking of which, while I am working on it I want to check and see if the ECM has been replaced. I will find the VIN to check on the recall but I wanted to look at the wiring around the ECM regardless. Is that beneath the cover under the headlight?

 

The ecm recall was for carb models only.http://www.cpsc.gov/en/Recalls/2008/...o-Fire-Hazard/ The hook up for testing fuel pressure is in the end of the fuel rail. Should be a black cap you remove.