Canister in friont of starter, what does it do? is it needed?

C

Carl Johansson

New Member
Dec 19, 2009
33
0
0
fresno Ca
OK guys,
in the middle of an engine change for our 24 hours of lemons supra. so the only stuff we need is a strong running engine. Emmisions are not an issue, cold start is not an issue, simplicity is valuable! There is a "canister" that sits in front of the starter, attached to the lower block. It appears as if it has vacuum line that goes into the bottom of some sensor on top of the intake. I am guessing cruise control stuff, and not neccisary, but I sure as heck don't want to take it off, and have it be something vital, that messes up the computer -

anyone know what this is? and if it can be safely eliminated?

Carl Johansson
 
C

Carl Johansson

New Member
Dec 19, 2009
33
0
0
fresno Ca
as wide as possible! I have determined itv is some sort of vacuum reserve, but i don't think it is connected to the brake booster, so thats not an issue. apparently it is part of the ACIS system, and I do not know what that is, or what it does!
 
Van

Van

87t Hardtop
Mar 26, 2006
974
0
0
Oak Grove, OR 97267
Carl Johansson;1849669 said:
as wide as possible! I have determined itv is some sort of vacuum reserve, but i don't think it is connected to the brake booster, so thats not an issue. apparently it is part of the ACIS system, and I do not know what that is, or what it does!
Click to expand...
Here is a quick quote from SM's 7MGE section:
Here is a combination of two posts in the stickied thread up there...

This looks like a nice place to expalin Toyota's air intake control system, or ACIS as it is now called.

First of all, it does not ever "kick in". The default position of the valve is springloaded open, which is high rpm use. Vacuum pulling on the diapragm closes it to boost low RPM torque. The manifold with longer runners aids low end torque, but starve the engine at higher engine speeds. The shorter ones lose velocity, but can fill a cylinder at high RPM.

So the system is set up for high rpm, and closes the valve for low speed torque. If you really feel it kick in, your probably does not work, and the vacuum solenoid is froze. Take a good look at that stock torque curve, and how flat it is.

The ACIS is designed to shift the torque band higher along the rpm range. It does this by responding to changes in the throttle opening angle (VTA signal of the TPS) and engine rpm (NE signal in the CPS). The air control valve is then opened or closed by the ECU via a VSV and vacuum actuator.

The valve is located in the center of the manifold and when closed divides it into two sections - a front chamber for cylinders 1 to 3 and a rear chamber for cylinders 4 to 6. A closed ACIS valve has the same effect as lengthening the intake manifold while an open valve has the same effect as shortening the intake manifold. In other words flow efficiency what's being controlled.

When the ECU turns on the VSV vacuum is applied to the actuator and closes the valve. When the VSV is turned off atmospheric pressure is applied to the actuator and opens the valve. There are four combinations of speed and throttle angle the ECU uses to decide when to open or close the ACIS:

1) Above 60% throttle angle and above 4,200 rpm: VSV off, ACIS open.

2) Above 60% throttle angle and below 4,200 rpm: VSV on, ACIS closed.

3) Below 60% throttle angle and above 4,200 rpm: VSV on, ACIS closed.

4) Below 60% throttle angle and below 4,200 rpm: VSV off, ACIS open.
Click to expand...
If the drivers are going to run the engine above 4200 rpm most of the enduro... Van
 
I

IJ.

Grumpy Old Man
Mar 30, 2005
38,728
0
0
62
I come from a land down under
jetjock;1849776 said:
That's because there's no vacuum pump on GEs :icon_razz
Click to expand...
Was on my 86.5 :p
(couldn't keep up on hills though)

vac.jpg
 
You must log in or register to reply here.
Top Bottom