MSefi.com read only forum (Jan.15,2018)

I think I have a USB to Serial problem. TS functions fine with the stim and in the car as long as the motor is not running. The motor runs fine with the MSII. I am only running the sensors and ignition timing at present. With the motor running the TS gauge screen locks up and moments later it goes "offline" Everything must be shut down and cables plugged back in for TS to function again. At idle I sometimes can keep TS operating for a minute. If a I rev the motor it takes 18 secs to lock drop connection. I have to tune off line and burn and I can only do a short data log. I am using a Dell Inspiron with Vista. I have the USB adapter( from DIYAutoTune) pluged on the MSII and I am using the supplied USB cable to the laptop USB receptacle.
I have read other threads and seems they used other combinations of cables.
Thanks for any help.

I have the USB adapter( from DIYAutoTune) pluged on the MSII and I am using the supplied USB cable to the laptop USB receptacle.

Take the USB cable out of there and plug the adapter directly into the laptop. Use a standard DB9 serial cable for the extension.

LT401Vette wrote:

I have the USB adapter( from DIYAutoTune) pluged on the MSII and I am using the supplied USB cable to the laptop USB receptacle.

Take the USB cable out of there and plug the adapter directly into the laptop. Use a standard DB9 serial cable for the extension.

Thanks for the quick and clear response. Are there any length limitations? I wound like to tune outside of the car sometimes.

With a real serial cable you can usually get pretty long, read serial is much more resistant to EM noise than USB. If you use USB extensions it needs to be a well shielded cable.
I have a bit of write up on this here:
http://www.tunerstudio.com/index.php/fa ... nnectivity

Good and bad news. I followed your directive and replaced the long cable with a good RS232 one and put the adapter on the laptop end. TS no longer drops out or disconnects. Unfortunately I now see that the Megasquirt II could also have an intermittent issue.
Many thanks for solving the cable nose issue.

Did a search and found this string because I am suffering the same exact issue. My laptop communicates with the MSII just fine as long as the motor isnt running. As soon as I start the car, it loses communication. I am running the cable and adapter that I purchased from DIY (as well as the driver that I installed from them as well). I will try the cable thing and see how that works. Any other thoughts?

It does sound like it's induced interference of some sort. Difficulty is finding out how well your serial cable is screened without destroying it. I tend to make up my own so I get the correct length and find decent twin screened mic cable works well. Same stuff as I use for VR sensors. I have a 5 metre long one I use here in the workshop between PC and the workbench for MS.

ecorl wrote:Did a search and found this string because I am suffering the same exact issue. My laptop communicates with the MSII just fine as long as the motor isnt running. As soon as I start the car, it loses communication. I am running the cable and adapter that I purchased from DIY (as well as the driver that I installed from them as well). I will try the cable thing and see how that works. Any other thoughts?

Yes with the DIY Cable and adapter, use the adapter plugged directly into the laptop with a standard RS232 cable. Don't use the USB cable that comes with it if you are having drop out issues. That will generally fix it.

Thanks Phil. Will try it this evening and let you know.

Phil,

It was the cable. That fixed it!

BTW, another unrelated but interesting problem that peter florence and I came across: I am running a chevy v6 odd-fire motor, electromotive ignition, MS2 for fuel only. The thing would start and die after 5 seconds or so. The logs showed a drop in the tach signals so the fuel pump relay cut off. We thought there was something wrong with the crank trigger but the tach was showing a constant, steady RPM up until the fuel pump shut off. We checked the MS2 board with the stim and it was acting really funky. We changed the MS2 settings over to even fire and all the problems went away! Turns out, when using the MS2 for fuel only, it does not like the odd fire signals coming off the electromotive tach signal.

ed