Benchtesting MSx3, HEI-7, vr-distributor - No RPM input?

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BigBlockMopar
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Benchtesting MSx3, HEI-7, vr-distributor - No RPM input?

Post by BigBlockMopar »

Benchtested the following setup to see if I can take-over the ignition-timing with MS, but the MS is having no control over the HEI-7 module it seems.

The setup, when operational, generates sparks just fine because the HEI-7 is running the show in bypass-mode, but the MS3 is seeing no RPM-signal, and can't therefore modify timing.
Double checked the wiring / connectors and such.
Trying to find out what what's wrong, and to check next.

Eventually the MSx3 will installed and be used for Ignition only.

- MSx3, prepped for vr-input, adjusted/connected according to manual, chapter 6.4 & 5.2.6. (Adjusted R56 to read 2.5v on R54).
- HEI 7-pin module.
- Chrysler electronic distributor (vr), mounted in a lathe, running 1100rpm.
- MSD TFI e-coil, with a sparkplug installed on a short leadcable.

Pin 24 on the V3 has about 5v. Pin 14 (SPK-A) and 33 (SPK-B) show nothing.

Also, reading the MSx3 manual, p125/126:
Typical Settings
Spark mode = "Basic Trigger"
Ignition capture = "Rising Edge"
Spark output = "Going High"
Spark A output pin = "MS3X spark"
Dwell type = "Standard Dwell"
Nominal Dwell = "3.0"
GM/HEI options = "GM bypass"

About the last line, I can't find this option in the Ignition settings in TS.
Is this a relic from an older manual setting maybe, or am I missing something?
Daily driver: 1973 Dodge Dart - 360ci engine - 11.3:1cr - MS3x - ignition only. 42RH/A500 OD+LU transmission / 3.23 gears
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Six_Shooter
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Re: Benchtesting MSx3, HEI-7, vr-distributor - No RPM input?

Post by Six_Shooter »

How have you connected the HEI module to the MS?

Have you added the jumpers internally, to connect the db37 pins to the correct internal hardware?
Tha Toy: 1973 Datsun 240Z Turbocharged, and loads of fun, now MS'd
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BigBlockMopar
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Re: Benchtesting MSx3, HEI-7, vr-distributor - No RPM input?

Post by BigBlockMopar »

I haven't installed any jumpers myself. I bought the MS3x some years ago, pre-wired for VR-input, which checked out (internal wiring).
(The MS3x can read the vr-signal/RPM from the (rotating) distributor in a standalone setup with no problems).

Want to start using the MS3x on my daily driver (1973 Dodge Dart), so like to use the HEI-7 setup, so it's easy to switch back and keep the car drivable, in case of possible issues.

I did check/follow the wiring into both connectors for pin 24, and pin 14 and 33 for SPK-A and B, but did not check for jumpers (didn't see any mention in the manual for this).

The MS3x only connection to the module is through the 3 pins on the HEI module (B,R, E).
Hooked up the wiring according the pic below;
Daily driver: 1973 Dodge Dart - 360ci engine - 11.3:1cr - MS3x - ignition only. 42RH/A500 OD+LU transmission / 3.23 gears
--------------
Website: https://www.bigblockmopar.nl/
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jsmcortina
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Re: Benchtesting MSx3, HEI-7, vr-distributor - No RPM input?

Post by jsmcortina »

BigBlockMopar wrote: GM/HEI options = "GM bypass"

About the last line, I can't find this option in the Ignition settings in TS.
Is this a relic from an older manual setting maybe, or am I missing something?
It is now called:
HEI/GMDIS, TFI, C3I Options

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

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BigBlockMopar
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Re: Benchtesting MSx3, HEI-7, vr-distributor - No RPM input?

Post by BigBlockMopar »

Thanks James.
The mention of 'adding jumpers and wiring', made me look into the manual a bit more.
Until now I had primarily looked into the MS3'Extra' manual, but I just noticed, in the MS3 'Base' manual, on p122, the same info on HEI-7, only WITH board modifications mentioned. These are however not mentioned in the MS3'Extra' manual.

I'm confused now if this has been left out on purpose, or this is just an error (I know how tedious it can be creating a manual).
Also the advised Ignition settings appear to be different;
The Base manual mentions Spark output = "Going Low", while the Extra manual says: "Spark output = "Going High".

I will have to check tomorrow if my MS3x has these mods done at the time or not.
Daily driver: 1973 Dodge Dart - 360ci engine - 11.3:1cr - MS3x - ignition only. 42RH/A500 OD+LU transmission / 3.23 gears
--------------
Website: https://www.bigblockmopar.nl/
YouTube Channel: https://www.youtube.com/c/BigBlockMopar
jsmcortina
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Re: Benchtesting MSx3, HEI-7, vr-distributor - No RPM input?

Post by jsmcortina »

BigBlockMopar wrote:The Base manual mentions Spark output = "Going Low", while the Extra manual says: "Spark output = "Going High".
Different hardware.
The MS3X manual is using the Spark outputs that are pre-made on the MS3X card.
The MS3 base manual requires you to customise to create spark outputs.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
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