just pinch the isc air hose. when idle controls fail. hot.
the 2 hot water hoses, both same temp? are hot.? if not, they are blocked or engine really is not 180F. or more.
the 1 cold hose is air hose. fresh.
air flows, from main fresh air tube (air cleaner end as source)
to the ISC and from there to the ISC flange and then into the box plenum. (this is primary idle air now,hot)
this is how it regulates idle.
the ECU does all the work , modulating the the ISC coil 200 times a second.
The IAC, under the TB needs to be at 180f< it closes about 150F. so if it's not full hot, due to water hose blockage, it will stick open. and engine will scream hot.
1500 is normal cold because the IAC is open. then. lots of extra air cold.
see here
![[Image: IAC2w2.jpg]](http://www.fixkick.com/sensors/sensor-icons/IAC2w2.jpg)
the water path is free at all times, no blockages ever.
the air path is blocked key off or in hand.
12vdc opens the valve.
http://www.fixkick.com/videos/FLV-all/showtime.html#ISC
hear the sound it makes,?
and can see it move. in 1 video.?
you can also see how far its piston moves in my video.
it can leak closed a tiny bit, all this old do. due to the rubber ring seat , wear.
as seen in my skeleton photos
![[Image: IAC-exploded2w.jpg]](http://www.fixkick.com/IDLE-AIR/Slide_Show/images/IAC-exploded2w.jpg)
btw when hot rpm is 1500
this means, the ECU has lost control of idle speeds, one of its big jobs (besides spark and fueling calcs)
the 2 hot water hoses, both same temp? are hot.? if not, they are blocked or engine really is not 180F. or more.
the 1 cold hose is air hose. fresh.
air flows, from main fresh air tube (air cleaner end as source)
to the ISC and from there to the ISC flange and then into the box plenum. (this is primary idle air now,hot)
this is how it regulates idle.
the ECU does all the work , modulating the the ISC coil 200 times a second.
The IAC, under the TB needs to be at 180f< it closes about 150F. so if it's not full hot, due to water hose blockage, it will stick open. and engine will scream hot.
1500 is normal cold because the IAC is open. then. lots of extra air cold.
see here
the water path is free at all times, no blockages ever.
the air path is blocked key off or in hand.
12vdc opens the valve.
http://www.fixkick.com/videos/FLV-all/showtime.html#ISC
hear the sound it makes,?
and can see it move. in 1 video.?
you can also see how far its piston moves in my video.
it can leak closed a tiny bit, all this old do. due to the rubber ring seat , wear.
as seen in my skeleton photos
btw when hot rpm is 1500
this means, the ECU has lost control of idle speeds, one of its big jobs (besides spark and fueling calcs)
http://www.fixkick.com