MS1 build issue - rpm tests
 

So yeah... build has been going great. A local miata friend let me borrow his megastim for the build and its been quite usefull.

I've made it through power/serial/cpu socket tests and was just testing the datalogging. I got it reading and all the stim controls make changes... except RPM.

I configured mine for the hall/optical sensor. Jumpered for it and all... nothing. I've rechecked/reheated all joints on the stim and the MS that could have anything to do with it... nothing. I've even installed the VR components, even though they are bypassed with the Hall/optical jumpers... Nothing.

Anyone have any thoughts? All components look good, solid joints etc... I'm stuck.

well i think its good that you checked it out with megastim ... other than that idk

I have same rpm problem
 

I am on the same step and am having the same problem.

I have found the following on the MSEFI form:

"Have you looked here:
http://www.megamanual.com/ms2/V3trouble.htm
especially 1, 2 and 10?

That document has a number of things you should look at (on a V3 main board) if you don't get a tach signal on the stim."

I have been to busy to try the info on that link but it looks like it steps you through testing the rpm circit.

Eddie

Yah, i've done part of it. I'm going to get some acetone/alcohol and do some cleaning also...

If I find my reason... I'll post it up here to see if it helps you.

please do the same ;)

I had the same problem, then I switched the RPM switch on the Stim and my tach signal came back. I don't know why I lost it, but switching the switch to the other position fixed it. Did you try this?

Keep us posted.

Contact cleaner just fixed a little gremliin on my board. I would HIGHLY recomend it now and when you are finished.

Can you elaborate? Switching it to what "other" position? I'm game for trying anything :p

And cleaner is a definite now :)

RPM switch
 

I moved the switch to both positions with no luck before.

The switch is on the stim right next to the RPM pot if you have v2.1 stim.

Does anyone know what these switches are used for?

Eddie

Well, I've cleaned the stim and the MS... no changes. I'll continue trying to debug.

v2 stim btw.

I got my rpm reading last night and was able to start up with megasquirt controlling fuel which was a great feeling. what I did was first, clean my board with rubbing alcohol and a toothbrush, then heating up each individual solder joint, taking extra special care at the 5 or six spots where there are three very close points. If there was too much solder, i removed some, if there wasnt enough, I added a bit.

You haven't done any of the board mods yet have you?

Make sure XG-1 is jumped the XG-2
TSEL is Jumpered to OPTOUT
TACHSELECT to OPTIN

I guess I'll try reheating them again.

I've done both rpm signal systems, and jumpered those 3 for the Hall/optical selection. Nothing.

What spots did you feel were the close points? I'm curious. The closest ones I saw where the Qs for the VR system... which isn't even used with the jumpers we use.

Sigh... I'll keep at it.

For the megasquirt to work on the miata the opto basicly just needs to be installed and thats pretty much
it. Let me look at the schematic and see if anything else is needed.

Yeah, basicly XG1 to XG2 basicly grounds one side of the diode in the opto.

D1, D2, and R12 just to pass the signal from TachSelect to the opto. R12 is pretty much
just for protection. It can be jumpered out too.

No luck yet... been over solder joints, cleaned board of excess flux and no help from the troubleshooting page....

ARGH! Anyone know the info of the one electronics guy that can help with MS repairs? I'm about at wits end.

Can you connect to MegaTune to make some configuration changes?

I can connect and read data from the stim. I just don't get RPM. So i've stopped around step 62. I even installed the VR stuff.. just to be sure :p.... even though the jumper settings for Hall... bypass it.

Well dont get too down, i think i may have fixed my rpm spiking issue ... but then it was replaced by intermittent restarts or possibly just loosing the rpm signal. Finally it just stopped starting altogether and i dont know wtf happened.

Heh... I'd just be happy to get any rpm signal at all. Then I can proceed to build the rest of the MS.

Stim seems fine, joints all re-checked. MS stuff looks fine also, also all re-heated...

:Sob:

Do you have the wheel decoder setting in megatune that the miata would use? Once that is set rpm no longer registers with the mega stim. If you have it plugged into the car though you should get rpm. This may not help you if you are trying just the default settings you have after you flash a new msnse version.

Splitime, try this: Open MegaTune with the MS connected and the stim disconnected from the MS, go to Basic Settings -> Codebase and Output Functions and in "Wheel Decoder (eg 36-1)" choose "Off" and in "EDIS" choose "EDIS". Disconnect the MS from power and power up the MS again (to force a restart).

DO NOT CONNECT THE STIM! Use a regular 12V supply, and put a string of wire in pin 24 of the DB37 connector (this is the tach input - I suppose you have done the pullup resistor mod, yes? Don't do this if you haven't put the pullup resistors!). Now, with the other side of the wire, quickly tap onto a nearby ground several times. This should register RPMs in MegaTune.

alright, i'll find a 12v supply and give it a shot.

Thanks :)

I got a 9v 300mA power supply. Outputs more like 10v though. Quality radioshack stuff :p

No help with it inplace of the 9v battery. I'll try the suggestions from Reverent now and see. (although, ive built the MSI v3.0 to the specifications of the megasquirt build. ... not sure about the pullup resistor stuff... I'll wait until someone posts more info. Also, I don't have the specific menus that Reverent is talking of.... I've got megasquirt v2.25)

Just in case... does anyone have the info of the gentleman who's offered to trouble shoot the MS systems for an hourly rate? I'm about ready for that... I'd like to get the MS working before I get into the heavy fabrication ahead of me.

btw, i don't connect to ecu when its set to MSnS extras. I get errors with MSnS. With MS1 in the config I can connect and get all but RPM (at the test spot in the MS buildup just past RPM component installing).

Don't know if this will help you.

If your board has the miata mods the stim won't give you RPM. Only way to test it is to tap into the CAS and give it a whirl in the real world.

Its built to the MS build specs. I was going to go back and do the miata specific mods. Just wanted to get it up and running, then do the simple tweaks.

So... anyone know the guy that does MS troubleshooting?

Do you connect with MT do you get the counter in the realtime display? no tach could mean a FUBAR crystal. Next thing I'd be concerned with is the counter IC on the stim.

Yup, clock tics. And the things in the build prior to RPM work... just not rpm :(.

So... I've reheated joints, cleaned with acetone and whatnot....

Random Q... should the lights in the Stim be lighting up?

I don't have it in front of me... but I'd say yes. you won't get the IGN or INJ to light because there is no engine speed... but PMP and the other light should be doing something.

Hurm, I wonder if they went in backwards.... guess I'll flip them and check :p

... not it :p

heheh... If you don't have it figured out by the weekend I'll sit down with the schematic and see if I can figure out your problem. Has this stim been tested on a known good MS?

It has not... its been checked over, reheated and cleaned, the rpm pots confirmed proper and such... but beyond that... nope.

Heck, I'd be willing to ship the stim out to someone to test.... its not mine, but the gentleman who loaned me it to build for him... would probably like confirmation.

I'm going nuts at this point.... i have a ton of fabrication to do... and would love to crank it out some weekend soon and start the car up at the end of the day :p

I'd offer to help on the stim test, but I don't even know my address at the moment (living with the in-laws till we close next month).

updated to latest MsNS-extra and got connected. Still no RPM.

Stim shouldnt light up until MS has outputs right? So no lights at this point in testing phase.

I can't remember.. I'll check tonight and get back to you.

I just kinda skimmed over this thread, but I was having a problem reading RPM as well. Did you set any of the wheel decoder settings (ie miata is Generic Wheel)? If so, in megatune you need to go to the Spark Menu, click on Stim for Wheel, and turn it on.

Just set it to ON and burned it to ECU. No change. Thoughts? do i need to on/off it?

If you don't have the miata mod installed yet I'd turn the wheel decoder off entirely and turn that setting to off.

I literally have no specific miata mods. I'm around step 60 and just finished building the basic RPM stuff. Setup for Hall/optical and jumpered for it.

No outputs of any sort built.

What version of code do you have in the ECU? Have you tried the B&G standard code? It comes preconfigured just right for the stim.

Tried it with the original stuff. Updated to the MSnSextra stuff upon a suggestion, niether works. Both will get everything but RPM working.... when it should be everything... including RPM.

do you have a scope available to you? or in the least a store that sells them so you can buy one and return it? I'd check that the stim is outputting the signal. If not, I should be in the new house in a few weeks, then I'll have an address for you to ship the stim to for testing.

I'll see what I can find, but I don't have a scope on hand... so i'll check shops.

Sorry I promised to help more and havn't done it... I've been low on time lately. I will help you out as much as possible if my schedule ever clears up (going to be working a 14 hour shift tomorrow it looks like, so maybe I'll get done early on friday).

Its all good. Im about ready to send it to the msefi.com recommended electrical tech. He will probably fix it in about 2 seconds... send it back then I can finish it.

sounds like a reasonable plan... what does he charge?

I think 45 hourly shop rate. He does electronic repair for his living. I talked with him, looks like i can send it and he'll do some more of the build during the hour paid minimum.

Guy seems to basically be the go too repair guy for the MS people.

not a bad deal, although one hour of repair is about 15% of the MS cost.

Packed up and going to him tomorrow.
He's going to trouble shoot it and then with excess hour left continue the build to save me effort.

score.

Looks like bad component on the Stim and one on the MS. Fixed and coming back. I'll be finishing it up... then its fab time.

rock on... glad to hear repair went smoothly.

I have rpm... time to finish this thing and get to the fab work.

Weeee....

Nice, get to it man. You have it installed to run NA while you fab or what?

(Or are you the guy that has to travel like 2 hours to a shop to work on the car?)

1.5hrs to the warehouse. With the MS ready (finished full build on it today, I'll do the miata specific mods tomorrow), we can trailer it to the work area and get too it.

It'll be started up on boost. Car is apart and ready for build.