Has anyone ever encountered this?

There's a tuner local to me who I rang about tuning my MS, he deals mostly in rally cars and has a proper RR setup etc but he told me that he wouldn't touch a Megasquirt as he's had nothing but bad experiences with it before. He told me that they inexplicably lose their tune and settings just randomly change and he's constantly getting people coming back to him saying their cars won't run because the tune has changed.

I have to say that I have actually experienced this, sometimes I would have TunerStudio running and the car running well and I'd switch the car off. I would then switch it back on immediately and for some reason TunerStudio would bring up a difference report and random settings would be completely different to the settings that where fine a second ago. For absolutely no reason that I can see.

Am I alone in this?

 

most tuners say that so you can buy their $1500 solution.

or

most tuners say that because a lot of MS users are dumb as ****, build them themselves, and have no clue what they are actually doing.

 

Nope (Microsquirt DIYPNP and MS3Basic).

But I have many times played around in TS "offline", forgetting a small change and then being surprised when I hook it up to the MS some weeks later.

As one of the major engine builders near me says; "We get a smidge more power and a better midrange using fuel injection, but the support issues are much less with the Mikunis"
If the Tuner have made this prioritization, he have his reasons. "MS" can be a number of different experiences, on the Miata it's almost hard to fail (if you can search and read, and don't think your "smarter").

I would personally not like to give support to MS users who does not have the capability to do a VEAL run, even if it's on a Miata. So I have to make use of my DIYPNP+VVTuner on my stale extra project instead of selling it...

in short

 

Some USB adapters have noise issues, and older firmwares (MS2/Extra 3.2.x and MS3 1.0.x and earlier) don't check the data as well as they should. There's also a bit of confusion created by some things that are only checked on start-up.

There are a couple things with the MegaSquirt that can make a tuner's job harder:

1. Home-built versions can be all over the map when it comes to build quality. If the problem is a hardware fault, most tuner shops aren't set up for board level electronics repair.

2. Traditional MegaSquirts have a lot of options for customization instead of a single, defined pinout. Figuring out how one has been customized can add extra challenge to the job.

3. With MegaSquirt being about the lowest on the price scale, it seems to have a higher proportion of people who try to do all of the work themselves even when they shouldn't. In such case, an install will take more straightening out wiring issues and the like.

4. Some people expect that if the ECU cost half as much, it also costs half as much to tune.

 

+1 to all of this. I've had a number of people call me for help diagnosing home built units, I don't touch them with a 10ft pole. A)It's not my specialty and B)Too many variables as you said.