RPM alternating 0-8500 rpm with stim

[quiksilverly]

I'm at step 55 with my MS2 3.0 board and it does mention I may not get a usable VR signal unless I tweek pots R52 and R56 but even when I do there is no change. Just alternates between 0 and 8500 rpm every second. Is that what I'm supposed to see?

[jsmcortina]

Install the current MS2/Extra firmware from the "Downloads" link above and see the "Manuals".

James

[quiksilverly]

Installed new firmware with the new downloader and now Tuner Studio says there's no firmware installed on the ECU..... It detects the controller on port 3 but says there is no firmware installed. The downloader shows a progress bar at 100% and then says it's complete but I need to load new MSQ file and reset my sensor calibrations. It just says hit enter then it exits the loader. I can't do any of that if TunerStudio can't see my firmware right? I'm stuck.

[quiksilverly]

Finally got the latest version matched up...I had the boot jumper on while trying to connect to TS. So now I do get a 20-60 rpm bump if I fiddle around with the stim at the bottom end of the RPM range but changing the pots mentioned in the board build is not giving me any better of a signal...I'm wired for the VR. Is this normal? I'm ready to move on with the build but don't want to go any further if I need to fix something first. Thanks for the link by the way.

[DaveEFI]

Are you using a Stim or JimStim? A Stim only gives a simple tach signal - not like you'd get from a trigger wheel, you need a JimStim for that. So is your software set for that?
When testing with a stim, I set R52 fully anti-clock, and R56 6 turns clockwise.

With a DVM set to AC volts, what reading do you get at Tach Select to ground, and Tsel to ground?

[quiksilverly]

TSEL to gound gives me 1.1V ac and Tachselect to ground gives me nothing. I have Tachselect jumpered to VRIN and TSEL jumpered to VROUTINV as I believe my engine uses High voltage inverted. So if the stim i have can't do that, how can I check for proper VR circuit wiring?

edit: where is the software do I change settings for Stim/Jimstim?

[DaveEFI]

If there is no AC reading at Tach Select, it looks like your Stim isn't generating a tach signal. Or a connection etc problem.

[kjones6039]

Repeating Dave's earlier question....... Are you using a Stim or a JimStim? They are 2 different things............

Ken

Afterthought............... This almost sounds like B&G code when you haven't selected the proper MS from the pulldown..... IIRC the tach would bounce from zero to ~8000...

[quiksilverly]

It just the regular stim, not the Jimstim. I Don't have the 0-8000 back to 0 problem anymore, now the latest code is on the daughter board. Now I just want to get some kind of evidence that the tach input and output wiring are correct. The instructions implied that I should be able to at least verify the signal even if it wasn't perfect. So the stim I have cannot generate an AC signal...is there another way to test this on my desk? One thing I should clear up is my R52 and R56 pot rotate in both directions infinitely...so how would I know 6 turns etc?

[slow_hemi6]

The pot adjustment will be different for squarewave from stim and for the VR sensor. When testing you just have to go past the maximum number of turns for that pot, in the direction you want to go to "home" the pot. If it was a 12 turn pot you'd go 13 or 14 turns in the direction you want, CW or CCW, to be sure it's homed at that end.