2015 Hisun Forge 110 No Spark, No Injector Pulse. Please HELP! Willing to pay $100 for help assisting with a diagnosis!

[AdamG]

I have a 2015 (EFI) Hisun Forge 110 atv that has no spark or injector pulse.  I have replaced the Stator/pickup coil and ECU and still can not get anything.  I have brought it to 3 different Hisun Service centers and no one can figure it out.  The last service center said they can get a very "weak" spark but that is about it.  I consider myself pretty knowledgeable about engines but this one has me (and 3 Hisun service centers) stumped.  I just uploaded the service manual for this machine.  Any help or advise that you can give is going to be much appreciated!

110 ATV Service Manual.pdf

[Savage3]

I would look for a short to ground.  

Also, check coil and pick-up. I know u replaced trigger, check it anyway!

Primary coil resistance 
0.18 ~ 0.28 Ω at 20 °C (68 °F)
• Connect the multimeter(Ω × 1k) to the
ignition coil. 
Tester (+) lead Orange lead terminal
Tester (–) lead Spark plug lead
• Check that the secondary coil has the
specified resistance.
Secondary coil resistance
6.32 ~ 9.48 kΩ at 20 °C (68 °F)

[Savage3]

. Pickup coil resistance
• Disconnect the A.C. magneto coupler from
the wire harness.
• Connect the multimeter(Ω × 100) to the
pickup coil terminal. 
Tester (+) lead Green/White terminal ①
Tester (–) lead Blue/White terminal ②
• Check the pickup coil for the specified
resistance. 
Pickup coil resistance 
459 ~ 561 Ω at 20 °C (68 °F)
(White/Red – White/Green)

[Savage3]

If those two components pass, check resistance in spark plug cap and replace plug. Check for spark again. 

If all that is good, check fuses, main switch, wiring connections for entire ignition system.

Most importantly,  check the battery for a minimum of 12.6 volts!

9.6 volts while cranking!

[Savage3]

Based on your description of the problem, my guess would be a short or not enough current due to some added resistance, blown fuse, or simply a weak cell in battery.

[Ben1098]

Do a simple voltage test on the DELPHI ECM.....BLK connector.....as follows:

Pin 18......+12 Vdc....Always Hot...Battery

Pin 15......+12 Vdc......ONLY with ign key ON.  0 Vdc with key OFF.

Also power grounds on BLK Pin 2 and GREY Pin 9.

[AdamG]

Thanks for the replies @Savage3 and @Ben1098.  I checked everything and the only thing out of spec is the pickup coil.  I am getting a reading of 119 OHMs when the specs say it should be 459-561.  The problem is that it is brand new.  I also tested the old one (the one that was on when it was running) and it has virtually the same resistance (116 OHMs).  AC voltage coming out of the pickup coil at cranking speeds without the spark plug in is 3.5 volts.  Not sure what it is supposed to be.  Could a bad rectifier cause a no spark/injector pulse issue?

I am at a complete loss.   I live in the Dallas, Texas area.  I would be willing to pay someone to diagnose.  

[Savage3]

Sounds like you have a short somewhere. Difficult to help with electrical problems without performing the tests. Follow the service manual step by step. The problem will be small and most likely due to corrosion, broken wire, or bad connection. 

Make sure your battery is good, very important! They wont run in many cases due to something as simple as low voltage.

[AdamG]

I did some testing last night and got some "weird" readings.  I tested the pickup coil from 2 different places; directly from the plug (got 119ohms) and at the end of the wiring harness that goes into the Delphi ECU.  The 2 pickup wires that go to the ECU are shielded with a grey exterior and foil looking interior (assuming for more insulation)  When I tested the resistance just before the ECU (where the pick up wire go into the ECU) I was getting anywhere from 8-10 milliOHMs.   I was assuming I should have the same resistance when checking just before the ECU but the resistance was drastically reduced.  I then tested the resistance of the shielded pick up wires and there is no resistance at all.  Not sure if this all makes sense and you are tracking with me.  I can take pics to better explain if needed.  Not sure if this is a red flag or normal.  Thoughts?

[Ben1098]

The pickup coil signal wire is shielded due to ECU input can "see" other "trash" like the starter current pulses.

You have a smashed cable which shorts signal to GND....this the mohm reading you get.  Shielded cable is toast....cut back the cable to leave two (2) pigtails.  Connect the open ends....ECM input and the pickup coil output(s).  Go to electronics store a buy a chunk of shielded cable...take sample along.....SOLD ER all 4 joints...route new wire run far away from starter HOT and the 3 PH stator to Regulator wires

[AdamG]

@Ben1098  Thanks for the reply.  I unplugged the shielded wires from the ECM and pick up coil (completely isolated) and tested each shielded wire individually and they both have 0 resistance.  It just does not make sense why the difference in resistance when it is plugged into the pick up coil yet there is no resistance when it is unplugged.  

[Savage3]

New or not, I don't believe that pick-up will work at 119 ohms. I've never seen one that is working less then 400 ohms. Whe you test it, is it off the machine?

[AdamG]

It was on the ATV when I tested it.  I tested the old one (from when it was running) and it is 116 OHMS when it was off the ATV.  

[Savage3]

I just tested my spare, it's new 439 ohms off the machine.

[Savage3]

Pickup coil resistance
• Disconnect the A.C. magneto coupler from
the wire harness.
• Connect the multimeter(Ω × 100) to the
pickup coil terminal. 
Tester (+) lead Green/White terminal ①
Tester (–) lead Blue/White terminal ②
• Check the pickup coil for the specified
resistance. 
Pickup coil resistance 
459 ~ 561 Ω at 20 °C (68 °F)
(White/Red – White/Green)

[Savage3]

We can't ignore the specifications provided in the service manual. 

That taken into account, resistance is not the best way to test. Dynamic would be better, was the voltage in spec with new trigger when you tested it?

[Savage3]

I have a new 200 ohm coil, I tested that with 3 meters. All three were at 153, 159, 151. 

I also put it on and cranked machine, the voltage was in spec.

So, resistance can be off a little and the coil still works. I'm not sure it can be off as much as yours.

[Ben1098]

Did you send a LA area code phone number.  I called 2x from 812 xxx xxxx..no answer nor voice mail...this you

[AdamG]

I did.  I just checked the message and I sent you the correct number.  Not sure what is going on.

[Ben1098]

Tried again....no answer....try [email protected]

Guessing what your question would be:

450 ohm vs 210 ohm coils.  Seen both used.  The 450 ohm had failure problems..thermal good/bad self healing.  Tech info...the output is the real object.  Internal construction better magnet and heavier wire/less turns (lower resistance) but gives equal pulse output.  Chino service manual...copy of Yamaha Rhino SxS clone copied Yam specs and NOT what was in machine.

Pickup coil.  Output is signal and signal gnd taken off BOTH ends of the coil windings.  Tech.....the pulses due to make/break of magnetic circuit are + and then - repeating as the flywheel rotates.  Coil can be wired wrong.....as in backwards....resulting in a timing error.  Most ign modules trigger off + edge.  Thus timing will be off.

Shielded wire consists of insulated signal wire(s) wrapped with a foil shield and then a bare (drain) wire wrapped around foil...all with a outer insulation jacket.  You application has a single center wire (signal) and the bare drain wire is signal gnd.  Smash the cable and the foil/bare wire will short to the inner signal conductor.  I've seen a wire tie too tight break down the insulation on well used machines.  In your case

1. Pickup R was "correct" at output at engine.

2.  Measured at Delphi ECM very low R...SHORT.....due to insulation failure in S cable.

3.  Measured R in both center and drain wires and OK.....these wires are still intact....will both be low R.

4.  The internal short will kill the weak pickup signal...ECM no timing signal....dead.

[AdamG]

@Ben1098  Thanks again for the info.  I just did another test and I think I confirmed the shielded wire is bad.  I hooked up my DVM directly to the pick up coil out of the crank case housing and got 3.9 volts AC when cranking the engine over.  I plugged the pick up coil back to the shielded wire, cranked the motor and tested voltage at the ECU plug and got 0 voltage (no signal going into the ECU).  I am going to try and find some shielded wire and make the soldered connections as you suggested.  I will report back to let you know if that fixed the problem.  

[Ben1098]

A fast test is just use 2 jumper/clip leads.  The signal will be good enough if NOT routed against harness.  If miss fire or sputtering,  shield the signal wire.  Grab some Al foil strip 1/2" wide...wrap length wise....finger roll tight...masking tape here and there and the ends (stay off the ends...no shorts) AND take a 3rd clip lead....attach to foil and a good ground (signal gnd).  Shielded cable on the cheap.

[AdamG]

SUCCESS!!!  Finally figured out the problem.  The plug that connects the pickup coil to the shielded wire to the ECU was bad.  Soldered the wires together and starts and runs good; under 10mph...  Lesson learned: check the voltage all the way to the ECU.

I took the ATV for its maiden voyage and it was only able to get up to 10-12 mph before cutting out.  Once under 10mph it kicks right back in.  It is not specific to the RPM's either.  Also I can fly in reverse but that is a little scary.  

Is there some sort of safety device on the ATV that limits the forward speed to 10mph?  

[AdamG]

So I figured out why I could only go 10-12 mph in forward.  I called "Motorcycle Doctor" out of Missouri and a guy named Craig is an expert when it comes to Hisun anything.  They also sell Hisun parts.  Once I told him what was going on, he immediately said he knew exactly what the problem was.  It is the reverse rev limiter.  He said cut the wire at the ECU and it will fix it.  I explained that it was not a problem in reverse or a revving issue, it just would not go over 10 mph.  He said it did not matter, forward or reverse, for some reason Hisun ECU's do not know what gear you are in (FWD or REV) and will limit your speed in forward or reverse.  I cut the wire he told me to cut and sure enough, no more speed limiter!  It does about 30mph with me on it.  It also runs about 9,000 rpms.  I did not think they spun that fast!  I uploaded the document that Craig sent me explaining what wire to cut.  I think this is just for the machines with the 2 plug Delphi ECU's.  In the document it says that it is a blue and green wire but mine was a green and white wire.  I confirmed via the service manual that I was cutting the correct wire.  Hopefully this helps someone else who runs into the same problem.