(4AGE 20V Silvertop) what does this connect to?

[hiroshima_scream]

I just plugged the yellow line into the ecru didn't make a diffenrece to the idle. When I block off the open pipe the car stalls. I will look for the idle up valve later to confirm

[jondee86]

Yeah it just stalls when I completely block it and if I partially block it off restricting the air
Idle is affected . Do you know what's that bit with all the hoses coming off it called?

The bit with all the hoses is the end of the common vacuum rail. The fat hose comes from
the ISCV, but it seems that yours has been plugged. Therefore, right now all your idle air
is going in thru that open port. As you have discovered, if you partially close that port off
with your thumb, the idle speed will drop.

By way of explanation; all the idle air for the 20V usually enters the vacuum rail by way of
the ISCV, and from the rail into each of the individual intake throttles downstream of the
butterflys. If you shut off the idle air, the engine dies. One way round (if you don't have a
working ISCV) is to crack the throttles open using the throttle arm stop screw located
between the centre two throttles. Or, easier, just attach some kind of cap to the end of
that open port, and drill a smaller hole in it. By adjusting the size of the hole, you will be
able to fix your idle at whatever rpm you prefer.

Downside is that there will be no ECU compensation for temperature, so your hot idle
will be a higher than when cold. Means cold starts might need a bit of a tickle on the
throttle until the engine warms up.

Cheers... jondee86

[hiroshima_scream]

Thanks for the explanation looks likemi gotta get an iscv. Would you know what should I plug into the map sensor?

[jondee86]

ISCV is that tan coloured solenoid valve immediately below the round part
of the vacuum rail. The other end of that fat hose should be hooked up to the
outlet pipe of the ISCV. Note that the ISCV is a PWM controlled rotary
solenoid, and needs one standard, and one inverted PWM signal to operate
correctly. My Adaptronic runs the valve fine; you will need to check if your
ECU has the ability.

Usual practice for aftermarket ECU's is to take a vacuum tapping off the
common vacuum rail, exactly as shown (yellow hose) in your pic.

Cheers... jondee86

[hiroshima_scream]

Oh cool thanks mate I'll see what I can dig up about the razorback ecu Merry Xmas

[BLK_20v]

It'd be good to get these hoses / rails explaned as it is one of the most common source of questions about the 20v manifolds.

I've lost count the number of 20v conversions that either idle way too high or stall.

[Sam_Q]

It'd be good to get these hoses / rails explaned as it is one of the most common source of questions about the 20v manifolds.

I've lost count the number of 20v conversions that either idle way too high or stall.

how about this then?

http://www.my-acoustic.com/Car/vacuu...39;_vacuum.htm

http://www.my-acoustic.com/Car/vacuu...cuum_lines.htm