HELP! 2006 Sportsman 700 EFI Dies for No Reason
I posted a thread several days ago that I had my 2006 Sportsman 700 EFI fixed--NOT!
Now I need to pick your brains some more.
My machine will run great for hours--and sometimes days--and then just die for no reason. Any RPM, any speed, it just dies--no rhyme or reason as to dry trail, wet trail, mud bog, hot weather, cold weather. If I try to restart it immediately it will seem normal for a second or two then die again. If I continue to try to restart it every minute or two, it runs longer with each subsequent restart, until finally it will run fine (minutes or days--who knows). It usually takes about 30 minutes to an hour for it to restart and run normally again. It throws no trouble codes when it dies and the speedo is not flashing HOT either. The fan seems to be cycling on and off when it needs to.
It could be heat related because it only does it at operating temperature and it restarts after a short period of time, which means it has also cooled down somewhat. It could also be an electrical problem.
To date, this is what Iíve done:
I've changed the fuel pump and filter sock inside the gas tank, and the voltage to the pump is good. I dismantled the entire fuel system, cleaned out the gas tank, gas lines and fuel rail, changed the filter and burned a tank of gas treated with Sea Foam. The fuel tank vent is also good. I've also covered the bottom of the gas tank with foil insulation.
The air filter is clean and the rubber intake boot between the air filter box and the throttle body is not cracked or rubbed through. The plastic throttle body adapter tube to the head is also in good condition. The clamps are tight in all the right places. The oil is clean and full as are all the other lubricants.
I changed the t-bap sensor, installed the beefier harness (the original was broken on the inside), changed the TPS (which was bad and I thought would be the final solution), and adjusted the TPS to within a thousandth of a volt of factory specs (zero offset and idle voltage). The TPS output reads good at the ECU plug as well. Spark plugs are in good condition and the coil and wires check out good.
Iíve removed and cleaned the contacts on the power and fan relays and their sockets (they were only slightly dirty but seemed to be making good contact). The fan works as advertised. The resistance at the coolant temperature sensor and the crankshaft position sensor are reading within specs at the ECU plug.
Iíve checked continuity for every circuit related to the EFI and found nothing out of order, though that doesn't mean there's not a short somewhere after she gets warmed up. The battery is strong and reads 12.8 volts. The machine reads 13.8-14.1 volts at idle.
Here are some possibilities that I can think of that I can do yet:
Change the TPS harness on the machine side (I plan to do this tonight), check the operation of the power and fan relays, and check the operation of the ECU. Change the self-resetting circuit breakers. Check the voltage regulator.
Anything I left out?
Iím running of the simple things except for the TPS harness and Iím afraid Iím narrowing it down to the ECU, which I donít want to replace at $400+.
Is there a way to check the operation of the relays and ECU myself? If I take it to the dealer it may or may not duplicate the problem and there goes a $100 in diagnostic labor.
Any and all input is much appreciated.
2011 Sportsman 500 HO Touring: Polaris 3500 lb. Winch, Kimpex Adventure XL Trunk, 7" Passenger Foot Risers, UNI Foam Filter
2006 Sportsman 500 X2 EFI: Superwinch Terra 25 w/Synthetic Rope, Kolpin 4 gal Gas Pack, 3" Passenger Foot Risers, 3-Headlight Mod, K&N Filter
SOLD 2010 Sportsman 300: Polaris 2500 lb. Winch, Kolpin Rear Seat (for the dog), UNI Foam Filter
SOLD 2006 Sportsman 700 Twin EFI: 27" Mud-Lite XTR, Superwinch Terra 35 w/Synthetic Rope, Polaris HD Front Springs, OEM Front Bumper Guard, WES Rear Seat, Kimpex Fender Guards w/Footpegs, 3-Headlight Mod, K&N Filter, Symtec Heated Grips