Joyner trooper Fuel injection

[Nutcase]

I have a Joyner Trooper 1100 4 place that has been sitting for a number of years. I have everything taken care of but i can't get the fuel through the injectors. Fuel pump puts full pressure on them but they don't turn on or spray fuel. Any ideas?

[Alien10]

Are they getting any "fire" signal from the ECM box on their wires?  Can you bench test them?  Siting for years lets fuel turn to varnish and can wreak havoc on injectors.   Just a thought. 

[Nutcase]

How do you check to see if they are getting the fire signal. The varnish is also a possibility that I considered but it had been sitting so long with no fuel in the system that I kind of thought that the electrical side was more suspect. I assumed that the pump signal would be the same circuit but maybe not. Do you know which fuse is for the injector signal. 

[Nutcase]

It starts and runs on starting fluid, so I know everything else is working, just no fuel.

[Dan B]

On the schematic I'm looking at (which may or may not apply to our Trooper), the injectors get battery voltage from the main relay through a 15 amp fuse and a relay.  The main relay is energized by the ignition switch in the run & start positions.  The injectors get a short duration pluse that might show on an LED circuit tester.  Incandescent lights can't react fast enough.  But will appear on an oscilloscope (that many may not have available).  If you can find a way to see that pulse, it will tell you if the injetors should be working.  If the pulse is there, the injectors are bad.

[Alien10]

First test all fuses in the fuse box to be sure they are good. Use a tester or simple 12v bulb & wire.  Then run a spark test to be sure you are actually getting spark at the plugs. 

It is my understanding from others that these Hisun injectors are very finicky about any dirt or gum in them.  Some of the Hisun based models came from the factory without an in line fuel filter and had starting and running issues resolved only by installing a filer and replacement of the injector.   Sitting for a long time would be my prime suspect in that the fuel if any in the injectors may gel or dry up leaving them inoperative.

Since the machine has been sitting maybe the best thing to do is replace the injectors regardless.  But that's your call.  

[Dan B]

If you can't clean the injectors, then don't limit your search to Joyner only engines.  John Deere and KawasakI and other lesser known brands use the 3-cyl version of your SQR472 engine.  But you might end up buying 6 injectors   They might be sold in  packs of 3) if you can't buy them individually to get the four you need.  You'll just have two spares.

[Nutcase]

I pulled the injectors and they would not cycle so I removed them from the manifold and they were full of varnish in chunks, I have them soaking in injector cleaner. Do you know what voltage the injectors work on? is it 12 volts?

[Dan B]

12v pulses

[Nutcase]

Guys, Thank you so much for taking the time to help out a fellow trooper. I have a two seat trooper that runs great and has had no problems. I bought this one for spare parts and found out that it had 288 miles on it. Figured it would make a great family buggy for somebody that doesn't have the budget for the name brand units. Once I get it running I will look for somebody that fits that mold.

[Nutcase]

If you noticed my picture, that is our shie tzu that absolutely loves to ride and drive the two seat version that i am normally in.

[Joe Breaux]

6 minutes ago, Nutcase said:

If you noticed my picture, that is our shie tzu that absolutely loves to ride and drive the two seat version that i am normally in.

Our 9 yr old Heinz 57 loves to ride in our UTV or on our ATVs too..he has a ball.

[Nutcase]

On 11/23/2024 at 12:34 PM, Alien10 said:

First test all fuses in the fuse box to be sure they are good. Use a tester or simple 12v bulb & wire.  Then run a spark test to be sure you are actually getting spark at the plugs. 

It is my understanding from others that these Hisun injectors are very finicky about any dirt or gum in them.  Some of the Hisun based models came from the factory without an in line fuel filter and had starting and running issues resolved only by installing a filer and replacement of the injector.   Sitting for a long time would be my prime suspect in that the fuel if any in the injectors may gel or dry up leaving them inoperative.

Since the machine has been sitting maybe the best thing to do is replace the injectors regardless.  But that's your call.  

This was the solution