[kraftada]

Hi all,
2018 exmark x series red technology.
Just bought used unit 1200 hrs. unit very clean and tight.
Changed fluids, filters, plugs etc.
Some cold starts dont go well. Slow rpm chug chug chug for a few seconds and stall. Seems like it
just cant get off the ground and go. Sometimes chug chug, slow increase in chugs then ramp up to idle.
Other times, fires up to idle ok. No codes stored, gas is fresh. Cut for two hours fine when first brought home. Any ideas welcome, thx.
Adam

 

[VegetiveSteam]

Is it black smoking out of the exhaust when it is chugging?

 

[kraftada]

Yes, I was just thinking last night that I forgot to mention you can see black rich out the exhaust. Its not terrible but you can see it.
Thanks

 

[VegetiveSteam]

If your unit were a little older I'd be thinking Throttle Position Sensor but that sensor design was changed around 2014 or 2015 and it's pretty much unheard of for a TPS to fail since that change. Not impossible but it would be pretty rare these days.

As of now will it ever run good? If you can never get it to run good as of today, look at the engine computer. You may or may not realize it but there are two computers on that engine. One is for the engine called the ECU or Engine Control Unit and the other one is for the electronic governor control unit or GCU. You'll want to look at the one mounted on the side of the engine. It will have a black and grey connector on it. There is a label on that ECU. Is it gone or look like the one in the first attached pic? It should like the one in the second pic. If it looks like the first pic I can just about guarantee you your ECU has moisture in it and is failing. That label covers a hole in the case of the ECU. Over time if someone gets a lot of water around that ECU the label starts coming off and moisture gets inside. That would explain no codes. The ECU doesn't tell on itself.

It might be worth it to let a Kohler dealer hook it up to their diagnostic program and see what it says. If they are a good tech they can probably tell you what the problem is in about 5 minutes.

Something I wanted to ask you and almost forgot. When you checked for codes did you get code 61 at the end letting you know it was finished checking for codes?

 

[kraftada]

Only looked in LCD and seen screen as attached. Also attached is shot of Ecuador for your thoughts. Thanks so much for you time and knowledge
Adam

 

[kraftada]

Photo ecu

 

[Scott87]

Check the voltage at the battery when cranking the starter. If it is dropping below 12 volts to much it may be time for a new battery. If you get 2 or 3 seasons on a battery for these machines, you shouldn't expect a longer battery life.

 

[VegetiveSteam]

Photo ecu

The engine trouble codes won't be displayed on the Exmark screen. That is just for the Red Tech. This unit doesn't use a touch pad to start it does it? It has a regular key switch right? Also, do you see a red light separate from the LCD panel? If so, that should light up when you turn the key to the on position. Let me know if you have that light and a regular key switch. Then we can get codes.

 

[kraftada]

Yes regular key and small red light next to LCD which goes green within a second or so

 

[VegetiveSteam]

Okay. Make sure the key is off and has been off for at least 15 seconds. That way you know the ECU has completely shut down. Now you want to cycle the key. On-Off-On-Off-On. The whole On-Off-On-Off-On process should be done in about 3 to 5 seconds. Not too fast. Not too slow. Once you do that the light should begin blinking. Each blink represents a digit. The trouble codes are all 4 digits long and all start with zero so if there is a trouble code stored the light will blink 10 times representing a zero and then blink the remaining numbers one at a time. It will blink a code, pause and then blink another code if more than one code is stored.

For example. If the ECU has stored a trouble code of 0337 the light will flash10 times, pause, then flash 3 times, pause, then flash 3 times again, pause then flash 7 times. Once the computer is finished with its diagnostics it will blink a 2 digit code of 61. If after you cycle the key it only blinks the 2 digit 61 code the ECU is telling you there are no stored codes.

If no one has ever done a computer reset there is a good chance you will get a code 0337. For whatever reason that seems to be a stored code in almost every ECU out there from brand new. It's normally an historic code which means it currently has no effect on anything.

No matter what, you should always get the 2 digit 61 code even if there are no other codes stored. A brand new perfect running engine would still give a code 61. Sometimes it is counted as a code 62 because after if has finished the light comes back on solid and that often gets counted for part of the code. Again, that's just the ECU letting you know it has finished its test.

Let's see if there are any codes and go from there. I have a few other thoughts but don't want to complicate it so I am going to go one step at a time.

 

[kraftada]

V Steam,
Again thank you for all your time and expertise. I got caught up in work this afternoon and didnt get a chance to pull codes. I will attempt first thing in the morning. Again, many thanks,
Adam

 

[VegetiveSteam]

No problem Glad to help if I can. I'm semi-retired from 25 years of training Kohler techs so I check this site often. It keeps me out of trouble.

 

[kraftada]

V.s.
I cant get unit to blink. I've tried every cycle speed on off on off on possible. Attach is shot of entire console for you.

 

[VegetiveSteam]

And that is the only light on the unit?

 

[kraftada]

I believe so, I will have another look about shortly.

 

[kraftada]

V.s.
I have looked it over no other lights that I see.

 

[VegetiveSteam]

I'll be honest. I know the engine very well but I don't know a lot about the Red Tech system. I do know Exmark had Kohler make some changes for them but I am not for sure what all of those changes were. I will contact the factory in the morning and see what I can find out. A typical Kohler EFI powered unit has an MIL (malfunction indicator light) on the control panel that lights up solid red when the key is turned to the on position. Once the engine is started the light goes out if there are no stored codes. If there are stored codes the light changes from solid to flashing. The flashing is how you know there are codes. That is when you would do the on-off key cycle to get the codes. It may be that the system is set so the codes can only be read with the diagnostic program. We should be able to get around that if you have a standard test light. I will find out more on the Red system in the morning.

 

[VegetiveSteam]

Adam do you have engine serial number or the complete spec number? Most electronic throttle body engines didn't come out until 2019 so I didn't think your engine would be one of those but there were some out in 2018 and those engines don't use the standard MIL. Does it matter where you set the speed switch or does it act up regardless? Thanks.

 

[kraftada]

V.s.
Once past the start issue(s), I do notice some udelations in rpm at idle it will +- 3 hundred or so. I have attached a photo of model number and serial of exmark. I would have to wait til home to get serial of engine.
Again, thank you so much for your help, you are amazing

 

[VegetiveSteam]

Well not too amazing....lol. I have yet to actually help you. So once past the start issue does it actually run fine and is usable? I may have mis-read. I got the impression all it would do currently was start and chug chug chug and never get up to speed.