SOLVED- 4G63 ICV help. Valve gets hot, doesnt work

[93supercoupe]

hello all,

Ive got a 94 US spec Eagle Talon (4g63) that im completing a MS3x install on. My last issue is the Idle valve. Im not sure whats going, so id thought id share. To be honest, im a little confused as to how the stepper system works in MS.

What happens is when the valve is electrically plugged in, it will get very hot to the touch and wont respond. Ive pulled the harness out and confirmed my wiring and it looks to be right. I at one point, thought i had a coil polarity swapped but still ended up with the same results.

I think the issue may be the fact that the valve, in stock form, is 6 wire. 4 wires for the coils (as you would normally see) and 2 more 12v wires coming from the harness.

Im wondering if anyone has ran into one of these valves before. I read a single line comment to disconnect the 2 12v wires from the plug and run the valve in the traditional 4 wire style, and im ok with that. But ive seen other info conflicting that.

[Matt Cramer]

We've been able to run them with the 12V supply. Just be sure the power between steps is set to "Moving Only" or it will overheat like you describe.

[93supercoupe]

it is. Looks like ill have to throw a meter on it and see what its really doing.

When testing the IAC wires coming from the MS, what should i be seeing when commanding a move? Voltage?

[billr]

Just checking... you have the coil center-taps (RED wires) disconnected, correct? What is the coil resistance, i.e. reading from pin 1 to 3? You will only be able to easily read voltages if TS is set to "always on", although "holding" may also give some joy. When the stepper is supposed to be moving, check for AC voltage between wires to an individual motor coil, should be something in the 6VAC range.

[93supercoupe]

I do not have the 12v wires disconnected. Should they be?

[93supercoupe]

Also, this is a DIYautotune ms3x 3.57 pre assembled. It looks like its setup to run the GM style 4 wire stepper motor already. Not sure if that changes anything.

[93supercoupe]

SOLVED- Removing the 2 12v wires from the ICV plug got it working. Also, the polarity is backwards from the stock configuration. I followed a pin out from ECM link which is a pretty credible source in regards to DSM ECU's. I just had to flip flop the coil A and Coil B wires, and it works like it should.

Idles alot better on megasquirt then it did on the AEM infinit we took out of it.

[93supercoupe]

Side note- ive been told it can work with the 12v wires still in place, but i couldnt afford any more time to figure it out.

[Matt Cramer]

If it works now, no point in changing it. Keeping the 12V wires in place is mostly a concern if designing a plug and play install.