ISC pin numbers

[Cobber]

Can anyone tell me what the pin numbers are on the ISC.

Looking at the back of the plug with the clip to the left the wires are as follows.

Top left = Yellow red
Middle left = Black red
Bottom left = Yellow blue
Top right = Yellow
Middle right = Black red
Bottom right = Yellow green

 

[Cobber]

Here is a picture of the isc pins.

Dahhh can't get the picture to work

 

[Peewee]

The plug should have the pin numbers cast into it (albeit tiny).

The 2 black/red ones are power, the other 4 are the control wires.

The 1UZ runs the same ISCV as the 7M
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=106

However, using that test page (page 107) I found that it didn't work.
I found to open it you did S1-S2-S1-S2 etc, and to close it you did S3-S4-S3-S4 (or could have been the other way around).

 

[Cobber]

Peewee,

Many thanks for the link, I will have a play tonight. The only numbers I can see on the back of the plug is an 8 and a 0.

 

[Cobber]

Peewee,

Mine works exactly as per the link.
1,2,3,4 to close 4,3,2,1 to open.

Looking at the back of the plug with the clip to the left the wires are as follows.

Top left = Yellow red (S2)
Middle left = Black red (B2 +12v)
Bottom left = Yellow blue (S4)
Top right = Yellow (S1)
Middle right = Black red (B1 +12v)
Bottom right = Yellow green (S3)

Gave it a birthday clean up and will throw in a couple of new bearings for the sake of it.

Thanks

 

[V8Datto]

Just a thought,.... might be a dumb one but Im still gonna ask.

Can you disconnect say the s1 wire so the valve would not sit in the full open position thus lowering the idle speed at start up, or maybe changing the s1 signal to the s2 signal so it sit's just that little bit closer.

Problem I have is at start up my car idles at 1300rpm.
I've checked the ISV, removed it, cleaned it etc but still sit at 1300.
If I clamp the air line feeding the ISV valve the engine dies so I know it's the solution to the problem.

I have a feeling the ecu wouldn't like this and have a hissi fit, also it's a conversion and some of the original ducting for the intake is gone.
(Idle at running temp is 600rpm)

 

[Cobber]

S1 is only one part of a sequence to open or close the isc. On cold start up you will have a high rpm due to other things like cold start injector etc as well. When warm 600 rpm is the target so your engine is running exactly as it is supposed to.

When the engine is warm and running at 600 rpm un plug the isc, switch off the engine and re start the next day without pluging in the isc. See how it runs and what error codes you get.

 

[V8Datto]

I'll give that a go next time I drive it. thanks.

The reason the high idle is a issue is because when I put my foot on the brake and stall up the auto the back tyres will start to turn at 1500rpm.
Kinda annoying when the idle is somewhere like 1300

The other thing is at 60kmph I have to ride the brake to slow the car down, not much brake but If I let go it'll sit around 70.

 

[Peewee]

Make sure your throttle butterfly is 100% closed.

If it is then the gearing of your car is quite bad.

In O/D it should almost go back to idle when you take your foot off the accel (or slow roll down to about 40kph).

 

[V8Datto]

TB is 100% closed, first thing I checked.

At 100kph it sits at around 1800rpm in O/D

 

[sideshow]

i have seen some 1uzs idle at 1500 to 1800 when cold

mine being auto used to shittttt me

so i stuck a good sized nut with small hole as a restrictor in the pipe that feeds air to idle motor

by changing nuts with diff holes inside to get desired idle i found one to be just right

i think an 8mm internal thread nut will do

on a cold mornin and i just woken up and i wasnt awake to good heheh
i would have to hold brake hard otherwise it would push car forward due to the 1500 rpm

but with nut in there it ok

when it warms up its a beautiful 650 rpm

 

[V8Datto]

That's a great idea, I did think about restricting that air flow other way's but that's simpler.
But doesn't that come back to the same problem with the ecu? wont it think the ISC unit is faulty?
either way I'll give that a go as well, and then see what code's it pulls.

 

[sideshow]

had it running like it for 3 years and no probs

ive seen 2 isc units seize up in my 4 yrs of wiring about 40 1uzs

 

[V8Datto]

Grinded down a nut last night to fit snug inside the air feed line to the ISC,
Internal size of 8.5mm but found the rev's only dropped about 200rpm, I then added a washer with a internal size of about 6mm. Now idle is dead on 1000rpm.

It's so much better, it finally doesn't pull when cold at idle, :yup:

 

[Peewee]

Mine idles at 400rpm when warm, in gear, and with the aircon on.
About 500rpm with the aircon off.

Everything I've checked has been fine, so I'm guessing its the ECU, needs some capacitors replaced or something.

 

[V8Datto]

If you want to raise the idle can't you just screw the stopper out on the TB to hold it open a little, just enuf to let a small amount of air past?.
That would lift the idle.

Sure it's not going through the ISC but that shouldn't matter