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4000/4010 MULE STALLS

59K views 24 replies 8 participants last post by  davidson310 
#1 ·
i have 4 09 mules that i maintain at work. all of them stall constantly. they usually start fine but after you move and come to a stop they stall. they even stall after you rev the engine. they run great as long as you can get moving but stall when you stop. the dealer blames the ethynol in the gas. i've done all i know to do without leaving it with them. the engine light is not on so they say there is no codes to scan so all the sensors shoul be fine. i don't have a way to check the fuel pressure-it should be 41046psi at idle-but they told me if i turn the key on for 3 seconds i should get 1.7oz or more out of the line. i get anywhere from 2.5-3oz which they say is good and my pump should be fine. i cleaned the screen on the pump and even removed it for a day on one too see if was restrictive. i've changed plugs, air filter, adjusted the valves even injector cleaner in the gas and still no good. even removed the drive belt in case a converter was engaging but no luck. if any one has had this problem and figured it out i would really appreciate some help.
 
#3 ·
You want the new air temperature sensor design installed. The dealers will stonewall you, so just get the new sensor via the parts catalog, it is #21176-2106. There are still some of the old style sensors in the system, so be sure you do not get #21176-2096.

Get one and try it before you replace all of them.

The other really critical issue is the fuel. If you run anything but LL100 for aviation, you will have fuel injection gumming issues. It is necessary to use an additive in all regular pump gas to avoid the wax build-up. This is true for all marine and alcohol free gasoline for automotive use too. Just crappy gasoline! Interestingly enough the additive needed is acetone, a very small amount will keep the wax build-up down. 1 ounce to the tank of gas. Too much and you will take out the pressure seals, so go easy.
 
#4 ·
Thanks for the info I'll try the temp sensor. I have been adding sea foam to the fuel regularly. I'll keep you posted on the sensor results but it may be a week or two-you probably know how slow these kawasaki dealers are at getting parts in. Thanks again
 
#6 ·
The problem will likely be the fuel injection nozzles if the sensor is good, the plugs are new, and the valves adjusted.

Read my comments to the guy that was looking at a 4000, same thing applies to all fuel injected utility rigs. Fuel is a problem and once the horse is out of the barn you have expensive repairs facing you.
 
#7 ·
Perhaps this can help. I am in the middle of diagnosing the exact same problem with a 2011 4010 gas/Trans at the moment.

I was originally not able to reproduce the problem. Customer came to pick his Mule up and first thing I noticed was that he had the tendancy to "floor" the throttle when starting. He took it with him, said he needed it a.s.a.p.

It's back today. Same problems. I duplicated it though this time. If I floor the pedal (or anywhere near wide open throttle), then turn the key on and then to start, the engine will rev up before I get my foot off of the pedal. Then when it settles down, it idles very low and stalls eventually-sometimes it's almost immediate, sometimes it takes a few seconds, and sometimes it'll idle at 450-480 RPM (using KDS software) and then just quit. In watching the sensors, it looks like the DFI system expects zero throttle input when turning the key to the on position and cranking the engine. Now if I open the throttle before turning the key on, then start the engine and THEN let off the throttle, I am seeing a TPS voltage that is lower than expected, which then closes the sub throttle ALL the way, which reduces the idle speed and eventually causes stalling. Also--once it stalls I am seeing that it's extremely hard to restart unless I turn the key off, take my foot off the throttle completely (zero throttle input) and then start it. From that point on it runs perfect until I start the process all over again.

We ran into this back when we sold Jet Ski watercraft. On the early FICHT 1100 STX DI (direct injection), if we held the throttle at anything but idle, turned the ignition on and then started the engine, it would not idle at all. It was explained to us by Kawasaki that they don't have adaptive learning stragegy built into the DFI....basically means that each time the key is turned to the on position, it reads all sensors and assumes that there is no throttle input. If for some reason the throttle is opened, and then the key turned to the on position and/or started, it more or less confuses the ECU and when you do let off the throttle to attempt to idle, the TPS voltage is lower than expected and the engine idles accordingly...the more the throttle is open during the startup process, the worse the idle speed.

The Mules are using a style of Alpha-N EFI meaning in a nutshell that there are very few sensors. Intake air pressure sensor, Intake air temp sensor, and 3 throttle position sensors (and two separate throttles...one being computer controlled which sets the governed top RPM and the low idle speed--called the sub throttle). If the main throttle position sensor is read as being open when the engine is initially cranked up, being that the ECU assumes that this is "idle" or zero throttle input, and then later on the throttle is released and the ECU gets confused. Confused enough to close the sub throttle completely which drops idle speed to very low speeds.

On another Mule in testing, we opened up the sub throttle's stop screw to achieve 800 RPM base idle speed. This was done by manually holding the sub throttle closed and then adjusting the stop screw until 800 RPM was seen on the laptop. Then locked the screw down. Kawasaki reccommends against doing this and says that the throttle body then has to be replaced, but if the TPS's are adjusted properly after doing this, it seems that they idle much better if the operator is one of those guys who tends to open the throttle before turning the key on & cranking the engine. We haven't had any feedback from the customer who has that mule, I told him what we did...and he may have changed his starting procedure which would prevent this from happening anyway.

Just something to think about. Kawasaki doesn't know about starting the Mules (the DFI ones...4000 and 4010) with the throttle opening. I asked the factory tech about it and he hasn't heard of it but referred back to the early fuel-injected Jet Ski as having the same potential issues.

And thus far, fuel hasn't been a problem with them in this area. Fuel PUMPS have been failing at an alarming rate (and they ain't cheap...) but most of them haven't had fuel quality issues...YET.
 
#8 ·
Interesting post, Cookie-monster. Keep us updated.

The $450 fuel pump failure issue seems universal with all brands of fuel injected gas powered UTV's. We see guys on their fifth or sixth fuel pump in just three years! Unbelievable failure rate.

We also see a great number of IAT sensors on the 4000-4010 series have been dropping like flies and throwing the rigs into cold start mode and flooding them to a stop at idle. They start, run a bit, then start loping and quit. No codes generated that KDS picks up either. It gets really bad when the air temperature rises above 85 degrees F. The symptoms are very much like the massive problems that Polaris has been having since 2008 with the throttle body failures that take out their ECU's.

We now steer all of our regular customers into the far more reliable diesels as the result of massive fuel injection problems with the gas models of all the manufacturers.

These gas engine fuel injection issues have been a sad state of events for gas UTV owners, but a real boon for the very affordable John Deere HPX diesel and Polaris Ranger Diesels, both of which are equipped with the totally bulletproof Yanmar engine and click along at 35 mph.
 
#9 ·
It's back today. In watching the sensors, it looks like the DFI system expects zero throttle input when turning the key to the on position and cranking the engine. Now if I open the throttle before turning the key on, then start the engine and THEN let off the throttle, I am seeing a TPS voltage that is lower than expected, which then closes the sub throttle ALL the way, which reduces the idle speed and eventually causes stalling. Also--once it stalls I am seeing that it's extremely hard to restart unless I turn the key off, take my foot off the throttle completely (zero throttle input) and then start it. From that point on it runs perfect until I start the process all over again.

throttle input. If for some reason the throttle is opened, and then the key turned to the on position and/or started, it more or less confuses the ECU and when you do let off the throttle to attempt to idle, the TPS voltage is lower than expected and the engine idles accordingly...the more the throttle is open during the startup process, the worse the idle speed.

read as being open when the engine is initially cranked up, being that the ECU assumes that this is "idle" or zero throttle input, and then later on the throttle is released and the ECU gets confused. Confused enough to close the sub throttle completely which drops idle speed to very low speeds.
I believe that there is a problem, but this alone is not the cause.
If I read you correctly, you believe that if the throttle is opened during cranking that a "calibration" of the throttle position sensor is done which then causes problems.
I do not believe this is true for the following reasons:

1. There would be no need to calibrate and stake the sensor itself if the ECU was not looking for absolute voltages.
2. It should set a throttle position sensor error code with "out of range" being the cause.

I do have a few questions:

1. Is there an adjustment for base idle and where is it?
2. Does the sub-throttle control fast idle?
3. Does it stall hot/cold using the throttle open starting procedure?
 
#10 ·
The initial idle is set from the main throttle assembly. Take a look at the Throttle assembly slide in the parts diagrams. You will see a set screw with a lock nut on the back side. That will adjust initial idle, but you should do it with the KDS so you know where to adjust the sensor for correct reference voltage (you will see it has slotted tabs for the mounting and adjustment bolts).

Fast idle is controlled by the main throttle (that is the one that is run from the step motor controlled by the ECM/ECU). The throttle control you step on only controls the sub-throttle valve which is upstream of the main throttle valve.

The system measures pulse air pressure from the inlet air sensor, and does not use a true atmospheric pressure sensor, so if you start at pedal to the metal throttle position the pulse air reading confuses the ECM/ECU and attempts to compensate for a non-existing condition. Sets the throttle too lean and then it will stall as it warms and the system looks to cut fuel delivery.

Kawasaki calls this "simple and reliable," which is PR spin for cheaper than a logic circuit and true atmospheric pressure compensation. If the owner does not follow the starting procedure outlined in the owner's manual they end up in trouble.

This system does work quite well if the fuel is kept fresh and of reasonable quality. These fuel injected gas rigs run forever with zip for trouble in countries where politically formulated gasoline is not in vogue.
 
#11 ·
So you are saying that curb idle is set with a screw on the main throttle butterflies (controlled by stepper motor) and fast idle controlled by the same butterflies via the stepper motor?
Then foot pedal throttle (which you called sub-throttle) has no direct control over these items?
 
#12 ·
Also, there seems to be a mix-up in which throttle assembly is which.
Even by dictionary terms, the sub (sub meaning under) throttle assembly should be downstream (putting it under) of the main throttle assembly. Naming it any other way makes no sense to me.
 
#14 ·
I have noticed if I turn the ignition on and wait for the fuel pump to stop and the light to turn off 9 times out of 10 the mules seem to run right. Occasionally they stall after a long run when you come to a complete stop but if you try to restart them without turning the key back off they are hard to start and won't idle. Thanks for the reply you guys are way more helpful than our local dealer. They seem to think everything is fine if there are no codes and the fuel pressure and flow is good.
 
#15 ·
Hello there, hey i have a problem also with a kawasaki mule trans 4010 4x4, here is the deal, our customers have the mules used near the beach, they are really bad for the year they are.. we change the stator and the magnet due to the salt, made it stuck, afterwards we change the drive shafts....

well the thing here came just after we change the stator and shaft, also fuel pump, the dfi came on... we notice that it wouldnt start, and found out that the throttle assy was damage, the valve wouldnt open... after this we change de assy throttle, worked for 3 days, and the dfi came on again... our customers said, that the mule started cranking up with out being the key put on the switch, like if it was a ghost on it.... any hint on what the issue of the dfi can be?
 
#16 ·
Late getting back to the sub versus main throttle discussion. Kawasaki is not the only fuel injection system that defines the upstream throttle valve as a sub-throttle. It is a pretty common practice.

If the main throttle servo were disabled, you would be lucky to get the Mule to move. The sub-throttle is for starting and initial sensing of the fuel demands. The main throttle is where the real action takes place, but it is purely drive by wire and operated by the ECM signals to the servo.
 
#17 ·
Hello there, hey i have a problem also with a kawasaki mule trans 4010 4x4, here is the deal, our customers have the mules used near the beach, they are really bad for the year they are.. we change the stator and the magnet due to the salt, made it stuck, afterwards we change the drive shafts....

well the thing here came just after we change the stator and shaft, also fuel pump, the dfi came on... we notice that it wouldnt start, and found out that the throttle assy was damage, the valve wouldnt open... after this we change de assy throttle, worked for 3 days, and the dfi came on again... our customers said, that the mule started cranking up with out being the key put on the switch, like if it was a ghost on it.... any hint on what the issue of the dfi can be?
The problem is likely corrosion in the wiring harness and at the ground points, and possibly a damaged ECM/ECU.

Salt spray requires a great deal of special preparation to keep all the electrical contacts protected and clean. Then what we see as usually happening is that something like a stator fails because it was improperly grounded, the customer changes it without disconnecting the battery first, and electrical surges during the repair process takes out other components.

Another common issue is simply one of salt water corrosion in the key switch. That causes all sort of unusual electrical gremlins.
 
#18 ·
Late getting back to the sub versus main throttle discussion. Kawasaki is not the only fuel injection system that defines the upstream throttle valve as a sub-throttle. It is a pretty common practice.

If the main throttle servo were disabled, you would be lucky to get the Mule to move. The sub-throttle is for starting and initial sensing of the fuel demands. The main throttle is where the real action takes place, but it is purely drive by wire and operated by the ECM signals to the servo.
Deleat.
 
#19 ·
Hello there, hey i have a problem also with a kawasaki mule trans 4010 4x4, here is the deal, our customers have the mules used near the beach, they are really bad for the year they are.. we change the stator and the magnet due to the salt, made it stuck, afterwards we change the drive shafts....

well the thing here came just after we change the stator and shaft, also fuel pump, the dfi came on... we notice that it wouldnt start, and found out that the throttle assy was damage, the valve wouldnt open... after this we change de assy throttle, worked for 3 days, and the dfi came on again... our customers said, that the mule started cranking up with out being the key put on the switch, like if it was a ghost on it.... any hint on what the issue of the dfi can be?
Did you check the ECU for codes?
 
#21 ·
Actually the stator is grounded through the battery ground and the rectifier. Once the normal ground connections fail, the stator will no longer be regulated by the regulator/rectifier and tries to sink excess electrical energy into the nearest ground it can find, usually internally, overheats burns out the insulation, and shorts to ground or burns out a wire.
 
#22 ·
I am not meaning to bust your chops RCW, but I do enjoy a discussion (not arguements) about such things. So here are my points:

1. A delta wound shunt regulated permanent magnet alternator has no "direct" connection to ground.
2. A ground reference is not established until after rectification as per normal full wave rectification standards. Center tapped transformers excepted.
3. Now, if a ground was lifted in the system, where it occured has some bearing on the result.
4. If the ground was broken at the reg/rect, then alternator current would stop. Alternator voltage would rise to its open circuit value, 60 to 90 volts, but unless that voltage is enough to break down the winding insulation causing a short to ground, or punch through (PIV) one of the solid state components in the reg/rect, there will be little heat generated in the stator because there is no current flow.
5. If the ground was lifted at the battery, taking the battery out of the circuit, the altenator voltage would continue to remain stable as the regulator voltage sense and ground are still intact. Now, because of the reduced load on the alternator as a result of no battery, the SCR's will be asked to sink more alternator current which might, maybe, possibly result in them overheating causing a regulator failure.
 
#23 ·
mY 4010 SUDDENLY QUIT AFTER BACKFIRING AND SLOWING. Plugs are wet. Spark is strong. Charge voltage is 12.8 volts. Battery is strong. No clogged muffler. It will run with rear plug removed and rear injector disconnected, but as soon as I reconnect the rear injector it will stall. New injector? Mule has only 48 hours on it.
 
#24 ·
OLD POST!!!

But updates.....

check the oil level. Lot of times lately I'm seeing a ton of them with oil level above the "full" line. All it needs to be is in the checkered area. Over time with excessive idling, low speed running, and cool air, the oil level WILL rise, so you have to keep an eye on it. Also sometimes the rubber grommet on the dipstick will come loose, which gives you a false reading. If your rubber is loose, replace it. If oil level is above the full mark, change the oil (don't just drain a little, replace it). Make sure you replace the washer on the drain bolt. New filter also (and I suggest the kawasaki filter since it's guaranteed to fit and work properly).

Once past the oil issue....

grab a can of carb cleaner. Grab a hammer or something to "brick" the gas pedal. Make SURE it's in neutral, start the engine, floor/block it, and with the intake tube removed from the throttle body, spray the carb cleaner into the throttle body. The engine will start to flood out, stop spraying, then repeat as the engine catches back up. Repeat until you use the ENTIRE can of carb cleaner. The throttle body has a tendency to "gum up" (closed crankcase ventilation system is the root cause), which holds the sub throttle valve butterfly open a little (or restricts airflow depending on how gummed up it is), which throws the sub throttle sensor's reading "off" which then "confuses" the ECU, which then it tries to compensate via adding or removing fuel, which makes it run poorly.

Valve adjustment. If the valves are tight (clearance tighter than spec), it'll cause pulsating in the intake manifold which causes the intake pressure sensor to "think" that the engine is under a load, which then the ECU "richens" up the mixture--and yep you guessed it, runs like poo.

The system is simple and crude, and honestly doesn't take much to "confuse" it. It's a hybrid open loop MAP and alpha-N system, both are a little more sensitive to changes in airflow and manifold pressure than, say, a true feedback MAF system. It's a good system for a lawn mower, but not so great for the Mule application. The engine itself IS a lawn mower engine, and a great one, but when used on the Mule, it's original design doesn't take as well as it does to running 3500 RPM all day long at full load in a generator/mower application. On that note, it's wise to run the Mule in low gear only if you're only running 10mph or less. Takes the load off the belt drive system, the engine will warm up, it won't be as apt to carbon up the throttle body, muffler, etc, and it will not hurt a thing. It's just better for it.
 
#25 ·
OLD POST!!!

But updates.....

check the oil level. Lot of times lately I'm seeing a ton of them with oil level above the "full" line. All it needs to be is in the checkered area. Over time with excessive idling, low speed running, and cool air, the oil level WILL rise, so you have to keep an eye on it. Also sometimes the rubber grommet on the dipstick will come loose, which gives you a false reading. If your rubber is loose, replace it. If oil level is above the full mark, change the oil (don't just drain a little, replace it). Make sure you replace the washer on the drain bolt. New filter also (and I suggest the kawasaki filter since it's guaranteed to fit and work properly).

Once past the oil issue....

grab a can of carb cleaner. Grab a hammer or something to "brick" the gas pedal. Make SURE it's in neutral, start the engine, floor/block it, and with the intake tube removed from the throttle body, spray the carb cleaner into the throttle body. The engine will start to flood out, stop spraying, then repeat as the engine catches back up. Repeat until you use the ENTIRE can of carb cleaner. The throttle body has a tendency to "gum up" (closed crankcase ventilation system is the root cause), which holds the sub throttle valve butterfly open a little (or restricts airflow depending on how gummed up it is), which throws the sub throttle sensor's reading "off" which then "confuses" the ECU, which then it tries to compensate via adding or removing fuel, which makes it run poorly.

Valve adjustment. If the valves are tight (clearance tighter than spec), it'll cause pulsating in the intake manifold which causes the intake pressure sensor to "think" that the engine is under a load, which then the ECU "richens" up the mixture--and yep you guessed it, runs like poo.

The system is simple and crude, and honestly doesn't take much to "confuse" it. It's a hybrid open loop MAP and alpha-N system, both are a little more sensitive to changes in airflow and manifold pressure than, say, a true feedback MAF system. It's a good system for a lawn mower, but not so great for the Mule application. The engine itself IS a lawn mower engine, and a great one, but when used on the Mule, it's original design doesn't take as well as it does to running 3500 RPM all day long at full load in a generator/mower application. On that note, it's wise to run the Mule in low gear only if you're only running 10mph or less. Takes the load off the belt drive system, the engine will warm up, it won't be as apt to carbon up the throttle body, muffler, etc, and it will not hurt a thing. It's just better for it.

OK, so i have a situation that i posted elsewhere, but I feel that you have apt knowledge about this motor AND it is very similar to the situations that i am currently having... so here is the explanation...


I just bought this 4010 Mule off Facebook, seller said he bought it off a farmer and drug it out of the shed, put a new battery in it, washed it, and posted it. Original statement was that it was not getting enough fuel pressure, It starts, runs ( but slow, as if it was starving for fuel) and goes into forward and reverse, I figured why not! lol..

STEP # 1 -I bought the service manual, read it, determined that if I dont have atleast 40PSI of pressure on the rail i will be running into issues.... so pump it was....

My DFI Indicator light will illuminate at the beginning of ignition turn on, then after 3 seconds it will turn off ( as expected) I have yet to have any light flash from that indicator light.

Fast forward 1 week, I got a fuel pump repair kit off ebay ( replacement pump and filter) to rebuild my pump, I cleaned off the top of the tank ( with a power washer, and i was very careful not to go crazy spraying by the electronics under the drivers side of the front seat), replaced the pump parts ( that was fairly easy) put it all back together, and go to start it, I have great pressure at the fuel rail now! awesome! the old filter was horrible!.... all my problems are solved... NOT

Mule turns over BUT will not idle... it starts, runs for 3-5 seconds, then turns off, almost like the ECM is forcing it to turn off?

If i spray choke cleaner into the air induction tube, it will run off that until the fuel source ( choke cleaner) runs out.. which tells me that I am either not getting fuel through my injectors OR my injectors are flooding out and stuck open?

I mess around with it, I made sure that my lines were clean from the pump to the rail, everything seems to be in check, in my head there should be no reason that it doesnt start and atleast idle... but run better than it was 30 minutes before this?!?!?

Had some family stuff so I had to put this off for a couple days....I redid the carb cleaner test to confirm my plugs/wires/ and crank sensor were all still functioning, I opened the throttle and sprayed choke cleaner in, now it wont even run off of that? it acts like it is backfiring?

SO, now I am very confused... I am going through pages... I still have not indicator light showing codes on the DFI, same solid for 3 seconds at start, and immediately off, so I skip pages 3-36 through 3-39 about the self diagnostics port/ reading codes... (maybe this will bite me in the ass later.... but if its not flashing the ECM doesnt see a problem? right?

I continued on trying to "find a broken wire" It has to be some connection somewhere, a plug, a pin, or broken wire, there is no way it just broke sitting there doing nothing.... I DROVE it into my garage....

Pages 3-40 through pages 3-54 go through testing, replacing, and tracing the wires back to the ECM on the Main TPS, Sub TPS and Sub throttle Valve Actuator, I step by step go through the inspections checklist, testing each wire,I have continuity at each wire back to the ECM for both TPS's. My main TPS passes ALL the tests, my sub TPS passes resitance, and has 4.9V on the incoming wire (blue/red) HOWEVER the ground wire (brown/black) is not receiving anything from the ECM? I double checked that wires continuity to the ecm main harness, and i have a solid connection ( no broken wire) I then went through the checklist of how to test for quality ground and power TO the ECM, that passed with flying colors, everything i am reading is telling me to replace the ECM becasue it is suppose to supply me with ground but is not providing it... I tested this theory by grounding the wire to my chassis, thinking that if my TPS sensor was not being grounded, it could not return an accurate value to the ECM, and if the ECM thinks that the TPS is not working, then it will not let my Mule start.... It was a good idea... but did not work.... I was really pulling at straws there....


I am sitting at the threshold of paying $700 for a new ECU, and before doing so, I am praying that you have some input... I plan on doing valves when i get home from work, and I am going to try to clean up the throttle body with choke cleaner, unless you have any other ideas i need to be heading twords? Is there a way to "RESET" the ECM? am i flooding my plugs with the "OLD ECM SETTINGS" ( before i replaced the pump) and now because i have great fuel pressure it is allowing too much fuel in? my plugs are wet when i pull them after trying to turn the engine over so i am 100% positive i am getting fuel through the injectors
 
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