TJaruzel

To start off I am running a ms3 basic on my 1992 miata 1.6L N/A. I have been running megasquirt for a couple months now but still have some kinks to work out. One major one is my IAC valve doesn't seem to be controlled by megasquirt whatsoever. I go into the idle valve test mode and raise or lower the pwm percent and nothing happens to my idle. I have tried some different idle settings but can't seem to find a fix. This of course restricts my use of a.c. because the idle can't raise to compensate for the added load. Also, It needs a rev or two to get going especially when cold. Before switching to ms3 everything worked and a.c. did idle up so I don't think the valve has failed. Someone point me out some things to check out

SpartanSV

It's a lot easier to help you if we know your settings. Post your tune.

Also who built the MS3?

TJaruzel

Should be a Reverant built MSLabs ms3 basic. I attached my msq to this. Running firmware 1.5

TJaruzel

I still need help, but I have now found out even if I unplug the IAC it affects nothing.

Akina_Downhill

iTrader: (1)

Have you tried a spare iac valve that works for sure?
Did you try to install stock ecu to see what happens?
Iac pin is 2W, check your wiring.

Evolforce2

Sound like the wiring or output selection is off. If it worked before, then check the wiring again for continuity and correct termination at the ECU (IAC to pin 2W to DB-37 #_?). Then ensure the IAC output is on that pin 2W from which ever wire its on the DB37. I have a MS3X and its on pin 9 of the expansion board, but this does not help for your situation.

TJaruzel

My IACV has a red/white wire and blue/yellow wire. I have confirmed the idle output on ms3 does have a blue/yellow wire running to it at pin 2W. My next step will be borrowing my friends multimeter and testing continuity. Yes, my iac ouput is on idle which seems correct according to the ms3x harness diagrams online. If I test continuity and things check out, is there a way I can just wire it to my fidle ouput on the expansion (solid blue wire to the blue/yellow wire on the iacv) and that work?

TJaruzel

Alrighty, the red wire is supplying constant 12V, and when the wire passed the continuity test between the valve and megasquirt at pin 2W. I still don't understand why it does not work then. I also really doubt the valve failed bc it only did this directly after the MS install. What do you guys recommend trying now? I don't have any spare valves around to test nor do I really wanna buy one atm. All I can think to do is wire the valve do the db37 connector on the fidle output and set the output in MS to fidle and see if that does anything...?

TJaruzel

For anyone wondering, or that encounters similar problems. My valve was not bad at all. I did end up fixing it by rewiring it to the fidle output on the expansion. Change the output in tunerstudio and boom it's perfect cold starts are amazing, a.c. idles perfectly. Even a more steady idle and no rev to start. Thanks everyone for the insight

Evolforce2

That is wonderful you got it going. I never pulled from a different output before, so i couldn't comment on your intended plan. In theory it would work and you just proved it actually works. Good job. Hopefully this helps others out that encounter this type of problem.

StanTheMan

would this be relevant to the MS2PnP?