2018 Sector 250 hard to start, won't idle but runs great

[JDH]

Hi guys,

I have a Rural King version of the Hisun Sector 250 with about 75 miles and 15 hours on it.  It just started being difficult to start and idle.  But if I hold in on the gas a little it will start and run until I left off.  It also runs good and will run good until I stop then it idles for a few seconds then quits.  Its about 4 months out of warranty.  Battery voltage is fine before, during, and after starting.  Oil is clean and clear.  Gas is fresh.   I can hear the fuel pump spool up when I turn the key to actually start it, not when I turn it to the on position though like on most other UTV's I have owned.  Its really odd and has me perplexed.  The only other thing that I have noticed is that the engine temp indicator on the left side of the dash only indicates one bar regardless of how warm the engine is.  Other than that, it runs great.  Just hard to start and won't idle.  Any suggestions?  It has me  perplexed.

Thanks

 

Jason

[Travis]

Carbuereated or fuel injected?

[JDH]

3 minutes ago, Travis said:

Carbuereated or fuel injected?

Fuel injected.  I checked a few more things today.  After cranking it for about 7 seconds and not "starting it by pressing on the gas" I checked the spark plug and it was wet.  It was also a little black for a plug to have that few hours.  So its getting fuel, maybe too much but once I put it in gear and take off it runs like its normal.  Anything 500 rpms or higher than idle speed it runs great.  Could a slightly weak battery starve just enough voltage at startup to not make the plug fire good?  Then when the rpm's are up the stator takes over?  Just guessing.....

 

Thanks 

[Travis]

It could be. My limits of knowledge stop at fuel injection..

[kenfain]

Sounds like too much fuel to me. But spark is easily tested with a spark tester. There's some testers that are even adjustable to test how far the spark will jump. 

[Dave Piccirillo]

The EFI computer sets the fuel mixture based on the Engine Coolant Temperature (ECT) sensor.  Since your spark plug indicates a rich mixture and your engine temp reads cold, the ECT may be bad. I have seen this happen on EFI cars.  I don't think the ECT is very expensive or hard to change. Might be worth a try.

[kenfain]

I think that Dave's on the right track here.  I'd definitely test that particular sensor. And also verify the actual temperature. The thermostat is activated by heat. So if its working, the motor should be heating up. 

[JDH]

Thanks for your replies guys.  I might have fixed it.  I changed the idle air control valve.  That seems to have fixed it although I have only gotten to test it briefly as the temp here is cold.  I had forgotten that these fuel injected ones have an idle air control valve.  The old one seemed to be stuck as to not feed any air while trying to start the engine.

 

Thanks again and will update thread if appears to not be fixed upon further testing.