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ATV quits running after about 10 miles

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2.7K views 7 replies 4 participants last post by  Treacherous  
#1 ·
I have a 500 Sportsman Polaris. It will run fine for about 10 miles, then backfires, starts running poorly, then wants to quit. Seems to run OK when cold. Have replaced the spark plugs and the fuel filter. Also replace the fuel pump with a Delphi pump. It ran great for 12 miles, then backfired and started running poorly again. After it cooled off it would run again. Any ideas?
 
#2 ·
I just had this exact problem. One of the wires to the fuel injector was broken inside the insulation, barely an 1/8 inch from the socket. Push and pull on the wire while idling and see if it misses.

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#3 ·
AFTER IT warms up. Play with the wires going to the Tmap sensor. It tells the ECU what the air fuel ratio should be when normal operational temperature is reached. But I would guess a check engine light would illuminate

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#4 ·
Mine ran great till it warmed up. I'm thinking the heat softened the insulation, or caused the insulation to expand, allowing the gap in the wire to become large enough to miss. I tugged on the red wire and it pulled right off. The ends of the copper core were black from arcing. No check engine or error code.
Ran great till it got warmed up. Also ran good at full throttle.

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#5 ·
Sounds like the issues I had on my 04.5 700 EFI with the TBAP sensor. The wires weren't terminated properly in the sensor and would cut the connection at times and do all kinds of weird stuff.