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ISC test with megasquirt

turboflanagan

Well-known member
Joined
Mar 5, 2001
Messages
2,571
Location
Peachtree Corners, Georgia, USA
I have a megasquirt computer running the Galant. I am unable to adjust my idle and need some testing input.

I have a new ISC and have verified battery voltage on pins 2 and 5 of the connector (the 2 middle ones).

To verify the computer is grounding the other terminals, could I just use a test light connected to the "hot" pins and each of the grounds while trying to actuate the ISC? That would verify both B+ and ground.

The ISC vibrates when actuated, but I can't see that it is moving much when trying to run it from opened to closed positions.
 

swe_gvr4_1991

Well-known member
Joined
Jul 27, 2006
Messages
177
Location
Sweden, Alingsås
Did you wire in the MS yourself?
When we installed MS in my friends Volvo years back we simply did away with the ISC and used a stopper on the throttle. Then adjusted the warmup settings in MS. That way the car has perfect idle when warming and once it reaches normal operation temp.
 

Mdlimy

Well-known member
Joined
Apr 30, 2015
Messages
111
Location
Gresham, oregon
I am not familiar with what type of isc this motor uses but I have done plenty of megasquirt setups along with various other ems installs so I should be able to help.

Is this a stepper motor or pwm? How many pins? Do you have a diagram/pinout for the isc motor?

Robbie
 

strokin4dr

Well-known member
Joined
Aug 30, 2005
Messages
2,770
Location
Savannah, GA
99% sure it's a 6 pin stepper motor.
 

swe_gvr4_1991

Well-known member
Joined
Jul 27, 2006
Messages
177
Location
Sweden, Alingsås
Yes it's a 6 pin unipolar stepper motor. Here's the schematic from the manual:

GVR4%20ISC.png
 

turboflanagan

Well-known member
Joined
Mar 5, 2001
Messages
2,571
Location
Peachtree Corners, Georgia, USA
Thanks for posting that.

I have increased the timed step size which helped get it moving when actuated. I have gotten the idle up a little bit, but it is still not consistently holding the idle I set at different temp points.

The isc is working. The computer is working. I think I must be missing something that is causing the idle not to remain consistent.
 
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