IAC with jim stim 1.4

[ChevytoyR1]

i have a jim stim 1.4 and im trying to use the jimstim iac leds to come on but they dont come on with ms2... the reason im doing this is because i cant seem to make the iac on the car move also.. any help with this will be be appreciated..

or in other words how can i check if my iac outputs are working correctly with the jimstim??

i have MS2 v3 with 2.1.0d code

thanks

[jsmcortina]

Have you connected the 12V jumper from S12C to JS9(+12V) on the Megasquirt board?

Measure the voltage on the IAC wires. What do you see?

James

[ChevytoyR1]

yes i have s12c to js9 that the first thing i did when i converted to extra code..

the voltage i see on the stim output is as fallow:

I1A = .006V
I2A = 10.41V
I1B = 10.41V
12B = .006V

[racingmini_mtl]

With those voltage readings you should have the LEDs light up if they are connected correctly. Have you connected I1A and I1B to one LED and I2A and I2B to the other LED? Have you tried to reverse the connections (one way will light the LED red and the other way green)? And have you tested that the LEDs are functional?

Jean

[jsmcortina]

That sounds ok. Check your wiring on the JimStim and make sure you have a connection from the "IAC" JS pins underneath the MS2 card to beside the DB37.

James

[ChevytoyR1]

ok i get green light on both of them now

[ChevytoyR1]

well after messing with the stim some more i must of touch some wires where i wasnt sopost to now i get no rpm reading and the stim chip gets hot and the voltage regulator gets really hot

[ChevytoyR1]

Jean could i fix my problem by buying the 2.0 cpu from u and also to upgrade my stim? or could i have burnt something else up?

[racingmini_mtl]

You most likely won't be able to burn something else on it since the symptoms you mention usually mean the chip is toast. And yes you can buy a replacement CPU from me (or from one of the vendors). The replacement CPU is compatible with all board versions.

Jean

EDIT: And yes, that should fix your issue.

[bmbelo]

Hi there.

I have a MS-II V3 unit assembled with a 6cop wasted spark setup. It's for a BMW and I had to install the low voltage tacho out circuit with variable potentiometers. Initially, had a conflict within tuner studio relative to Tacho Out. Played a bit with TS and Idle settings and it went away...problem now is that I can't get the IAC LEDs to light up on JimStim. I get 10.xx volts on IAC2 pin adjusting the tacho out pots (0 on other IACs since they're not jumpered) and I still can't get them to lit up.

Any thoughts?

Thanks for your help, regards from Portugal

[racingmini_mtl]

How did you connect the IAC LEDs? Each IAC LED needs 2 connections. For the IAC operation, you would connect both side of the LED to the 2 IAC outputs (A and B). In your case, you need to connect the LED to the IAC pin you're using and the other side of the LED to ground.

Jean

[bmbelo]

I had left my I2A "not-jumpered" to JS2 since I'm only using I2B for my tacho out output. It does work now when connecting the other pin (9,10 from the 10 pin row) to earth instead of I2A. Thank you.

1. My question now is...do I also need to jumper JS2 to IAC2A or can I leave only JS3-IAC2B?

2. Another question if I may...I noticed I2B LED turns red or green depending on how I connect the jumpers. However, shouldn't it be alternating between the 2 colours according to every step the ECU sends? I tried turning RPM pot but the LED just remains stable in its colour - red or green.

Again, thanks for your help and input.


Regards from Portugal, Bruno Belo