RpFarm25 0 Posted January 29, 2022 I've got a 2014 Honda Trx420 that I'm having some issues with all of a sudden. I don't have very much experience with fuel injection so hoping someone can point me in the right direction. I bought this unit new and I've never had any issues with it ever until now. When I first start it, it seams to take a few extra cranks to fire up than usual, and then when it does fire it will only run for a second or 2 and then die out right away. Without cycling the key off and on again, I can crank it again and the same thing happens, running a little rough and then dies out again. A few more of these and it will start to slowly run a little longer each time, until finally the engine will idle on it's own. After its been idling for a little while and the engine seams to be at operating temps, then it seams to run great, I have no issues with idling or lack of power after that, and I can shut it off and it will start back up right away, unless I let it sit again for a few hours and then it's back to the beginning. New spark plug, Clean fuel tank, new gas and never sits long enough for the gas to go bad anyway. Battery shows 12 volts and battery tester shows good when a load is put on. I quickly checked the IACV and looked a little dirty so I cleaned it up and cycled the key with it removed and it spun the way it should. No change. I can hear the fuel pump running as normal when I first turn the key on. Computer isn't flashing any codes or engine light either. Put an an inline spark tester on to make sure nothing was shutting off the spark and it shows good consistent spark. I thought at first that it might be starving for fuel, but seams odd that it would get better once it was running for a while? Going to take the fuel pump out of the tank today and make sure everything is clean. Dealer told me it's probably the fuel pump and $400 for a new one, but seams odd it runs perfectly after a while. Again I lack experience with these new models so I appreciate any and all advice before I start throwing replacement parts at it blindly. I use this machine nearly everyday on my farm and with calving coming up soon I need it to be reliable again. Thanks Share this post Link to post Share on other sites
toodeep 1,760 Posted January 29, 2022 Did you get the fresh fuel from your normal/same supplier? I've came across this with a few customers and it was the fuel. They used straight unleaded from the same place. Replaced the fuel with 10% from that same place and the problem was solved. Cold temps amplified the problem. 1 Share this post Link to post Share on other sites
Fishfiles 20,147 Posted January 29, 2022 $400 for a new pump must be with labor , cause I looked the pump for your model up on Partzilla ( which they are high priced over other parts ) and it is $166 ---- I don't know if the fuel pump is your problem , or if you can even do it with a 420 , but my buddies with Can-Ams use a Mazda automotive fuel pump that goes in the tank for about $45 dollars from O'reilly's Auto Parts in place of the OEM and I have watched it being changed a couple of times , cause they don't like water run thru them ------- run a heavy dose of SeaFoam thru your tank Share this post Link to post Share on other sites
Misterclean 420 Posted February 4, 2022 I know that beginning in 2014 Honda added an o2 sensor. Check it with a multi tester? Share this post Link to post Share on other sites
Fishfiles 20,147 Posted February 4, 2022 25 minutes ago, Misterclean said: I know that beginning in 2014 Honda added an o2 sensor. Check it with a multi tester? I know the guys that ride in water do the o2 delete cause they won't idle well in the water , as far as what causes their problem , I have heard some say temperature change and others say back pressure , I think maybe even needing dielectric grease in the plug 1 Share this post Link to post Share on other sites
Misterclean 420 Posted February 4, 2022 Just now, Fishfiles said: I know the guys that ride in water do the o2 delete cause they won't idle well in the water , as far as what causes their problem , I have heard some say temperature change and others say back pressure , I think maybe even needing dielectric grease in the plug I've had two 420's without the 02 sensor and now have two 420's with the sensor. I have never had a problem of any kind. They ran fine last year when it was about 15 degrees here and I've had them at 13,000 elevation. The only difference is they are much more fuel efficient........so much in fact that they reduced the size of the fuel tank a few tenths of a gallon. Share this post Link to post Share on other sites