How to get tach signal from JimStim/base maps

[rithsleeper]

So searching for Base maps for my GM TPI setup with 8 pin connector and only found BMW's, Fords etc. No GM. Is there anyplace I could start with a base map for corvette TPI?

I have tested my JimStim for the blinking tach signal but when I connect it to the TunerStudio I'm not getting any Tach readout. There are soooo many settings that I'm thinking I have one not set to the GM 8 pin HEI mode.... I don't want to rip out all of my holley commander 950 till I am 100% sure the Megasquirt is working properly...

I found the test sequence for the JimStim, but can't find any step by step for testing the MS3 with the JimStim. Can anyone help me out? Gosh if I could just pay someone like $50 an hour to just come and spend a day with me I could learn 90% of what I need to know for this system.

Anyone want to know how to play the cello or Bass lol? I will trade knowledge!

[jsmcortina]

Have you read the GM HEI section in the Hardware Manual ?

James

[rithsleeper]

the part I have read and tried making the right settings was

These settings need confirming.
Ignition capture = "Falling" (check!)
Spark output = "Going High" (check!)
Spark A output pin = "MS3X spark"
Dwell type = "Standard Dwell"
Nominal Dwell = "3.0"
GM/HEI options = "GM bypass"

Anytime I try changing the "engine and sequential settings to 8 cyl" I get a notifactaion that there is an error syncing the rpm. Should have any jumpers installed on the JimStim? I just don't see anything about using anything from the jimstim

[jsmcortina]

What exactly is the error ?

and


James

[billr]

If you really want a kind soul to come visit and help, post where you are located.

[rithsleeper]

Really all that seems to be wrong is at the bottom of my main tunerstudio page, with all the error boxes at the bottom the only one that is red is the one called "not rpm synced". I have attached the MSQ. Sorry for not earlier. I live in Sumter SC, but seriously doubt anyone is in my area. Just a bunch of Dirt Track Carb guys. I have yet to meet anyone who works with FI.

[rithsleeper]

Am I missing something I should be posting? I just tried square wave and 12v pull up jumpers and nothing. Do I need a jumper to one of the main pins on the long row of 18?

Here is a pic of my setup if it helps:

[racingmini_mtl]

If you're using only the primary tach signal, that should be fine. If you are using a secondary tach signal, you need to connect the secondary tach output on the JimStim to your MS input.

Also, even with a single tach signal you may need to fiddle with the 2 trim pots on the MS board.

Jean

[rithsleeper]

So the jumpers I have set up in the pictures are right?so why would I still not get a tach signal? I tested the tach output for the jimstim and it blinks perfectly. So I should be tracking a problem with my main board? I get signals from all the other pots...

[racingmini_mtl]

Have you played with R56 and R52 (trim pots) on the MS board? Have you checked the tooth log or composite log in TunerStudio?

You may need to follow the signal from the JimStim to the MS CPU. It is easier to do so with an oscilloscope but you can get by with a LED and resistor.

Jean

[rithsleeper]

I know how it sounds but I'm sooo new to this. I'm sure in a year, I'll be contributing to the community, just as I did when I first got into cars and had to learn everything I know from the internet.

I don't know how track the ciruit. I can't see lines on the board and I guess I'd just be guessing to know where it goes. is there an actual diagram that shows each pathway? I'm really not finding it in the manual. I just did a datalog and saw no change in any of the tooth counts or anything except the O2, TPS, CTemp, MAT.

Any guides to tracking this signal? I find it hard to believe it is the actual MS board, and suspect it is somewhere from the Primary tach pin to the exiting the JimStim. Like I said the Tach signal with the LED lights up and flashes perfectly.

I really don't get how all these jumpers are supposed to work, and I can't seem to find a manual called "How to Use the JIMSTIM" I just feel like making the thing and having it should be worth more than "hey you can make the dials go up and down on your computer screen!"

Thank you for being patient. This seems like a steep learning curve and I know I'm missing a big obvious something. I can feel it. Act like I'm a 3rd grader, once I get going I'm sure I'll learn quickly.

PS: Have no idea what you mean by trim pots on MS Board. I thought pots were the dials on the JimStim....

[racingmini_mtl]

Have no idea what you mean by trim pots on MS Board. I thought pots were the dials on the JimStim....

Check the manual: http://www.msextra.com/doc/pdf/html/MS3 ... .4-71.html. This page shows the pots I'm referring to. And the same manual has the schematics for the board so you can see which components are parts of which circuits.

Jean

[rithsleeper]

Ok, think I might be on to something. This is one thing that I noticed when assembling the actual MS Board. Seems there are about 3 "guides" out there and they all differ slightly. The big difference was soldering the wires on the bottom of the board. In the link you said about the tach, I don't have the jumpers installed for the "tach to VRIN" or the "tach to VROUT"

Do I need both of those? I'm planning on using the HEI unit with divorced coil. The ignition system is off a 85 Camaro if I remember correctly. Mine is a GM 8 pin Module with a GM ACDELCO Coil, and a MSD housing.

Here is a pic of the bottom of my board. Can you tell me if I have the correct jumpers installed. I do use the MSX board also, since eventually I will swap to a trigger wheel and swap to a vortec distributor for the cam position sensor.

Thanks for your patience.

[jsmcortina]

You need some tach selection jumpers installed or you won't get a tach signal.

James