MTronic diagnostics / ecm failure symptoms

[MustangMike]

I have not noticed any of the "throttle response" problems in my 462 M Tron, but I will keep an eye on it. In fact, so far, the saw has impressed me with the throttle response. I mix 40:1 with AMSOIL Saber and 93 octane pump gas, and my saw just has a slight muffler mod. Did not want to change anything that would hurt the throttle response.

 

[PogoInTheWoods]

..... he gave me a “parts saw” 462 to swap components to try to diagnose my problem as they don’t have the correct cable to hook it up yet.

Priceless.

And I hereby rest my case.

 

[nohoff]

Its the same cable for all mtronic saws since release.
Seems you have to do a proper Calibration with the MDG1.
Calibration without the MDG is like tuning a carb with the limiters on.

 

[RI Chevy]

Then why the field calibration procedure???

 

[nohoff]

Same question: Why tune a carb with limiters on?

 

[nohoff]

Calibration Process with the software asks for the altitude and sets the limiters new.
You can set a higher altitude in the software so you have more range until you hit the rich side limiter

 

[RI Chevy]

Hmmm. Interesting.

 

[Moparmyway]

More thinkin’
Remembering more about the last time I used the 462. That hot day, the saw started normally but died the first time I squeezed the trigger. At the time I thought it was strange. When started again it seemed to run rich for a few seconds before it settled down to a normal idle. Ran great the rest of the day. Lots of short cuts, but quite a few long cookie cutters as well. You could be right about the saw having to correct for the hotter weather though. It would make sense that it would have too , really.Air density has got to be considered when calculating air/ fuel mixture.

M-tronic doesnt "calculate" mixture, it allways adds fuel first to see if RPM increases, once RPM decreases from adding fuel, it leans out. The way M-tronic hunts for the highest rich RPM, actually takes all parameters (altitude or density, temperature, etc) into consideration without actually knowing any of them. Pretty smart & KISS IMHO.

 

[Moparmyway]

More thinkin’
Remembering more about the last time I used the 462. That hot day, the saw started normally but died the first time I squeezed the trigger. At the time I thought it was strange. When started again it seemed to run rich for a few seconds before it settled down to a normal idle. Ran great the rest of the day. Lots of short cuts, but quite a few long cookie cutters as well. You could be right about the saw having to correct for the hotter weather though. It would make sense that it would have too , really.Air density has got to be considered when calculating air/ fuel mixture.

The VP sef I’ve been running is labeled as 94oct. Nothing available higher than that here. Not readily anyway. Most of my trigger time on these saws was in cooler weather. Thus, the first time I used it in hot, humid PA weather, I assumed something was wrong/off. Oddly enough, the carb 462 doesn’t seem as fussy as the mtronic saw to weather changes. They still cut fine, but their manners change. It lost its wow factor on the pissrev from idle lol.

Could/did either of you gentlemen try running it without the air filter to see if there was any noticeable difference ?

 

[ABarrick]

Could/did either of you gentlemen try running it without the air filter to see if there was any noticeable difference ?

Yeah I did. It didn’t seem to affect it much. I didn’t actually cut anything without the air filter though.

 

[ABarrick]

Its the same cable for all mtronic saws since release.
Seems you have to do a proper Calibration with the MDG1.
Calibration without the MDG is like tuning a carb with the limiters on.

I thought there was only one cable but I’m not one to argue unless I’m certain. I’ll convince him to let me play with their computer next time I’m in there.

 

[av8or3]

There is only the one cable that connects to this little black covered “port” on the right side of the carb. You are very fortunate to have the relationship you have with your dealer. I can’t imagine ANY chainsaw dealer going to the length those folks have to keep you happy. There is lots you’d find interesting inside that tester and diagnostic software. Doesn’t take long to check out the whole saw. You do have to run the saw to complete the tests but I’ll bet the whole program could be run in 10 minutes.
Do you think these folks could have run the tests, found nothing wrong, and rather than tell you that, invited you to figure it out for yourself rather than possibly confront you and maybe loose your business? It sounds crazy for sure, but I’ll bet it’s happened before.
Good luck with your saw, I’ll be paying extra attention to mine this summer to see if I can verify your observations in mine.

 

[farmer steve]

I thought there was only one cable but I’m not one to argue unless I’m certain. I’ll convince him to let me play with their computer next time I’m in there.

would that be our buddy Lowell by any chance? Haven't had any issues with my 462 since i got it but i haven't run it in the heat yet. it's stihl bone stock.

 

[backhoelover]

I have
Auto tune software
Mdg1
Briggs and kohler efi
Pet9000
Anyone close that wants to hook there equipment up is more than welcome to come to my shop. Anyone needing a specialty tool let me know. No charge

 

[RI Chevy]

Do the older Version 1 saws show the same type of information as the newer versions of mtronic when hooked up to computer?

 

[ABarrick]

would that be our buddy Lowell by any chance? Haven't had any issues with my 462 since i got it but i haven't run it in the heat yet. it's stihl bone stock.

The one and only

 

[ABarrick]

There is only the one cable that connects to this little black covered “port” on the right side of the carb. You are very fortunate to have the relationship you have with your dealer. I can’t imagine ANY chainsaw dealer going to the length those folks have to keep you happy. There is lots you’d find interesting inside that tester and diagnostic software. Doesn’t take long to check out the whole saw. You do have to run the saw to complete the tests but I’ll bet the whole program could be run in 10 minutes.
Do you think these folks could have run the tests, found nothing wrong, and rather than tell you that, invited you to figure it out for yourself rather than possibly confront you and maybe loose your business? It sounds crazy for sure, but I’ll bet it’s happened before.
Good luck with your saw, I’ll be paying extra attention to mine this summer to see if I can verify your observations in mine.

He’s not so much my local “chainsaw dealer”. I consider him more a friend that sells me chainsaws. I’ve been buying saws and parts from these guys for 15 years. They haven’t done anything to the saw. I asked about hooking it up when I picked up the other 462 and that’s when he told me about the cable. It was already after hours so I didn’t push it.

 

[farmer steve]

He’s not so much my local “chainsaw dealer”. I consider him more a friend that sells me chainsaws. I’ve been buying saws and parts from these guys for 15 years. They haven’t done anything to the saw. I asked about hooking it up when I picked up the other 462 and that’s when he told me about the cable. It was already after hours so I didn’t push it.

Nice to go in there and get called by your name. I hate to read other people's horror stories about their dealer. I always stop and say hi to Lowell even if I don't need anything. Helped him several times when he needed a 3rd hand working on a saw.

 

[backhoelover]

Do the older Version 1 saws show the same type of information as the newer versions of mtronic when hooked up to computer?

first gen you could not hook up software. You reset the carb controller with 2 9v batteries, I’ll see if I can’t find the Tb when I get home

 

[PogoInTheWoods]

Would certainly like to see that TI.