MS2 3.0 Rev 2.92 testing issues

Ask questions about DIY board assembly issues, fault finding and testing. (Covers all Megasquirt versions and board.)

Moderators: jsmcortina, muythaibxr

br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

Hello,

I have completed assembly of my kit and am doing some testing and have found that I have a few issues. I do not see an rpm response with the adjustment of the posts on the stimulator (non jimstim). I also do not get any O2 response which from reading the manual is related to the rpm circuit. I am unable to see a response on the o2 guage when disconnecting the stimulator then adjusting the o2 pot then reconnecting the stim. The indicator on the guage goes to the same place as before. I am also not seeing lights when the software is initially initiated so I am kind of at a loss.

I am trying to set the ignition up with a msd6al and a billet distributor that is locked out with the ms2 high current driver circuit. I have gone over the assembly insructions quite a few times and feel pretty confident with the assembly so I am turning to you guys for help.
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: MS2 3.0 Rev 2.92 testing issues

Post by Matt Cramer »

How do you have it jumpered for RPM input?

Does your Stim have a "NPN - PNP" switch next to its RPM adjustment pot? If so, how's it set?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
DaveEFI
Super MS/Extra'er
Posts: 4175
Joined: Sun Apr 15, 2012 12:55 am
Location: SW London, UK

Re: MS2 3.0 Rev 2.92 testing issues

Post by DaveEFI »

Matt Cramer wrote:How do you have it jumpered for RPM input?

Does your Stim have a "NPN - PNP" switch next to its RPM adjustment pot? If so, how's it set?
Is there an up to date description of the Stim anywhere that describes this switch and its function?
Rover SD1 3.5 EFI
MS2 V3
EDIS
Tech Edge O2
London UK.
br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

Re: MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

HI Matt,

I have the RPM selector switched to NPN.

I have the VR circuit jumpered per the megamanual build instructions.

"For the VR sensor:
Jumper VRIN to TACHSELECT on the bottom side of the PCB (near the DB37, opposite the heat sink.)
Jumper TSEL to VROUT"

Thanks for taking the time to try to help me out.

Brad
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: MS2 3.0 Rev 2.92 testing issues

Post by Matt Cramer »

The switch will supply 12 volts in NPN mode and ground in PNP mode. Try PNP mode with VR input.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

Re: MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

thanks Matt I have tried it in both modes and I still don't get a response in the RPM circuit.
br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

Re: MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

Looking at another post "http://www.msextra.com/forums/viewtopic ... 569778de1c" i found this test to test if there is a short on my board.

"To check for a short in the Megasquirt PCB, power up the Megasquirt on a Stimulator or on the car and check the following points for voltage with a multimeter.

You should find the same voltage as the battery voltage on the following points: S12, S12C, the center legs of Q9 and Q12, the left (non-banded) end of D3, the left leg of U5, and the left (banded) end of D9.

You should have 5 volts at the following points: S5, the two +5V holes in the proto area, the right (non-banded) end of D9, the right leg of U5, the left (banded) end of D19, and pins 1, 20, and 31 of the CPU.

Let me know where you find the correct voltages, and where you find the wrong ones."

My measuments matched what should be seen from a 9V battery as well as 5V in the correct locations.

I did however get roughly a resistance of 2.3 at L1 and L2, but my meter was jumping from time to time de to shaky hand frustration.

Is there anything here of use?
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: MS2 3.0 Rev 2.92 testing issues

Post by Matt Cramer »

That check is for a totally dead board.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

Re: MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

Last night I messed with the system some more and I finally got a response from the RPM and O2 circuit. I had been told in the past to adjust the trim pots on the 3.0 board to possibly get an rpm signal and I did with no luck. Last night I went back to those adjustments and kept adjusting till I finally got a response.

This was quite a bit of adjustment (10+) turns so for those that are having issues with these circuits just know that it may take quite a bit of adjustment to get a response if you don't have the luxury of verifying with an oscilloscope.

Once I got the rpm circuit operational the O2 circuit became functional with the correct IAT's, CLT's, etc..

Some issues to note:
1. The lights still don't seem to work on the board or stim? (Low battery possibly??)
2. The rpm circuit while responsive did not seem to want to adjust past 5000 rpm? (is this an issue?)

Thanks for everyone's help or attempt to help,
Brad
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: MS2 3.0 Rev 2.92 testing issues

Post by Matt Cramer »

br1070 wrote: 1. The lights still don't seem to work on the board or stim? (Low battery possibly??)
Let me know exactly what lights aren't working.
2. The rpm circuit while responsive did not seem to want to adjust past 5000 rpm? (is this an issue?)
Should not be a problem.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

Re: MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

Hi Matt,

I have not gotten back to you on the light issue, but I switched to a 9V battery to the 12V supply and I managed to loose the RPM and O2 signal. Of course me being a dummy I moved the trim pots before confirming if I still got signal with the 9V battery. I spent quite a bit of time trying to re adjust the pots to get the RPM signal with no luck. Is there possibly something else I could try? I do have access to an oscilloscope at work if this may help.

Thank you,
Brad
DaveEFI
Super MS/Extra'er
Posts: 4175
Joined: Sun Apr 15, 2012 12:55 am
Location: SW London, UK

Re: MS2 3.0 Rev 2.92 testing issues

Post by DaveEFI »

A scope does help to make sure the VR circuit is correctly adjusted.

The test points are Tach Select with will show the input to the VR conditioning circuit, and Tsel which will show the output from it. It's the output which is important - you should see an approximate square wave of something like 5v peak to peak. Once that is good, it's likely down to a software setting if TS is still not seeing an RPM signal.

However a VR input setting which is fine with a Stim may not be perfect for your actual sensor.
Rover SD1 3.5 EFI
MS2 V3
EDIS
Tech Edge O2
London UK.
br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

Re: MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

Hi Dave,

Thanks a bunch. I'll see if I can figure this out and I will post back. It is very possible that it is a software issue as the system was acting a little strange that evening. One of the lights on the squirt box started pulsing until I adjusted the RPM trim pot then the light stopped blinking. If I remember correctly TS also locked up and I had to restart.

Thank you,
Brad
br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

Re: MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

"However a VR input setting which is fine with a Stim may not be perfect for your actual sensor."

I considered this and contemplated moving forward with the install on my car since I did previously confirm that the board was functioning properly at least at one point.

Brad
DaveEFI
Super MS/Extra'er
Posts: 4175
Joined: Sun Apr 15, 2012 12:55 am
Location: SW London, UK

Re: MS2 3.0 Rev 2.92 testing issues

Post by DaveEFI »

br1070 wrote:"However a VR input setting which is fine with a Stim may not be perfect for your actual sensor."

I considered this and contemplated moving forward with the install on my car since I did previously confirm that the board was functioning properly at least at one point.

Brad
I'd still get everything working as it should on the Stim first.

In other words, be certain the hardware is functioning properly. Much easier to check on the bench than in the car. Especially on a home built one.
Rover SD1 3.5 EFI
MS2 V3
EDIS
Tech Edge O2
London UK.
br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

Re: MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

Agreed
br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

Re: MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

Hi Dave,

I finally got a break to use the scope to try to dial in the vr circuit, but I am unsure of the results I was getting. I was either using the oscilloscope wrong or the signal I was measuring was really noisy. I took a picture of the oscilloscope reading so maybe you could diagnose if I was measuring incorrectly or something was wrong with the vr circuit. Any help you could give me would be much appreciated.

Brad
br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

Re: MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

Hi Matt

"Let me know exactly what lights aren't working."

Honestly none of the lights are working. No Fuel Pump, Injectors on the stim or squirt....nothing. I do however get responses in Tuner Studio for Coolant, IAT, and TPS. Any Ideas?

Brad
br1070
Helpful MS/Extra'er
Posts: 51
Joined: Sat Jun 27, 2015 11:09 am

Re: MS2 3.0 Rev 2.92 testing issues

Post by br1070 »

I followed http://www.diyautotune.com/tech_article ... s_test.htm

Apply ground and 5V power to the input and check the voltage at pin 2 of U7. (4.93V)

When you ground the input, pin 2 of the U7 should have from zero to 0.7 volts. (1.02V)

Once you have adjusted R56, apply 5 volts to the input. (1.85V @ U7 pin3) (1.02 @ U7 pin2) (4.30 @ U7 pin1)
R56 adjusted (0.54V @ U7 pin3) (1.02 @ U7 pin2) (0.16 @ U7 pin1)

Once you have adjusted R56, apply 5 volts to the input. (4.93 @ U7 pin2) (2.85V @ U7 pin3) (0.16 @ U7 pin1)
(4.93 @ U7 pin2) (4.89V @ U7 pin3) (4.30 @ U7 pin1)

Next, ground the input pin. This should give you from 0 to 1 volts at pin 1 of the U7. (4.30V @ U7 pin1) (4.89V @ U7 pin3) (1.02 @ U7 pin2)
(0.16V @ U7 pin1) (0.55V @ U7 pin3) (1.03V @ U7 pin2)

Can Anyone confirm the results of this test? To me it looks like U7 is doing its job?
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: MS2 3.0 Rev 2.92 testing issues

Post by Matt Cramer »

Yes, it looks like U7 is working.

Could you scope the input and output of the VR conditioner on a Stim?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Post Reply