i was thinking if someone has an N/A, and someone with a dyno if they can go to them and put the car on the machine, and while its on open the lever for the acis manually by hand while its at a lower rpm like 2500, and see if it makes some power or loses, just a tought, also what opens the valve i think its a vacuum type switch any way we could get it to be controlled at different rpms
i have an idea on how to play with the acis
- Thread starter Toyotaxtreamteam
- Start date
http://www.cygnusx1.net/supra/library/TSRM/em/EM_50.html
I don't know if that really helps with your idea but it shows how the system works.
I don't know if that really helps with your idea but it shows how the system works.
It works by vacuum, and is controlled by the ECU. Its not variable. Its full on or full off.
It changes the air flow, which is done by lengthening or shotening the intake runner.
Many companies use this method (altho different setups) to adjust and modify engine torque. Smoe do it to get better fuel economy at cruising speed (Ford Windstar).
I played with mine in real life, on the street, for quite a while. I hooked up a seperate vacuum source to see if I could gain more torque at lower RPMs. It did not, so I hooked it back up to factory setup.
It changes the air flow, which is done by lengthening or shotening the intake runner.
Many companies use this method (altho different setups) to adjust and modify engine torque. Smoe do it to get better fuel economy at cruising speed (Ford Windstar).
I played with mine in real life, on the street, for quite a while. I hooked up a seperate vacuum source to see if I could gain more torque at lower RPMs. It did not, so I hooked it back up to factory setup.
IIRC on the manual race car injection, the longer the intake tubes the more torque you get and the shorter they are the more rpm.
I may have it backwords though as its been years since Ive serviced a mechanical system.
I may have it backwords though as its been years since Ive serviced a mechanical system.
IJ. said:What would they know
They've been racing longer than any one on this forum, and have spent $$millions.
yea but they also dyno it for gas mileage and shit which i ain't too worry about, i might jam it open from the outside and take a ride to see what rpm it starts to pick up better
The natural torque curve of the 7MGE determines when it goes to a full plenum, or half. Changing the cam timing could change the optimum point for opening the valve. But I like having low end and high end both.
are you all talking about that little plunger type thing that has a metal stick that goes inside a metal spaceship shaped thing? um...lol....yeah.
I was playing with the throttle with the engine off (key in on position) and at full throttle i hear a click...i went under the hood and i hear what is actually a suction type "thook" sound when i pull the cable to full throttle...
is that the valve that opens up the plenum? i dont know anything about it...what part of the plenum is closed exactly, unless at full throttle?
IF this is the thing you're talking about...after several repeats of trying it out it eventually got quiet and didnt want to do it anymore...is that because its out of vaccuum or going bad? if i'm thinking of something else i'll delete this. lol.
I was playing with the throttle with the engine off (key in on position) and at full throttle i hear a click...i went under the hood and i hear what is actually a suction type "thook" sound when i pull the cable to full throttle...
is that the valve that opens up the plenum? i dont know anything about it...what part of the plenum is closed exactly, unless at full throttle?
IF this is the thing you're talking about...after several repeats of trying it out it eventually got quiet and didnt want to do it anymore...is that because its out of vaccuum or going bad? if i'm thinking of something else i'll delete this. lol.
I don't think the TPS input effects the valve operation. It is at a specific RPM. It is just over 4000 RPM.Figit090 said:
It is a butterfly valve, much like a throttle body that cuts the plenum in two. The newer systems such as on the 1MZFE Camry are more complicated and work better. It has mutliple valves and is staged.
TPS= Throttle Position Sensor. It is a potentiometer that modifies a 5 volt refrence telling the ECU the drivers intentions. It is technically an injection correction.
I don't know how I missed this one. That is how it is controlled right now. The vacuum switch is controlled from inside the kick panel.
I don't have an N/A and have never played with one but I'll be happy to reproduce what the factory training manuals state.
7M-GE Intake Air Control Valve System:
Located in the air intake chamber, the air control valve is used to increase the air intake efficiency of the air supplied to the cylinders. It does this in response to the throttle opening angle (VTA) from the TPS and the engine speed signal (NE) from the distributor. The valve is opened and closed by ECU via a VSV and an actuator. This makes it possible to improve engine performance at both low and high speeds.
The air control valve is located in the center of the air intake chamber and when closed divides it into two sections...a front chamber for cylinder numbers 1 to 3 and a rear chamber for cylinder numbers 4 to 6. Closing the valve has the same effect as lengthening the intake manifold while opening the valve has the same effect as shortening the intake manifold.
VSV:
The ECU turns the VSV on and off. When the VSV is turned on vacuum is applied to the actuator which fully closes the valve. When the VSV is turned off atmospheric pressure is applied to the actuator which fully opens the valve.
Operation:
The ECU turns the VSV on and off depending on the throttle opening angle and engine speeds as explained below. (There's a diagram so I'll have to explain it).
There are four possible combinations:
1) When the throttle angle is below 60 degrees and engine RPM is below 4200 the VSV is off and the air intake valve is open.
2) When the throttle angle is at or above 60 degrees and engine rpm is below 4200 the VSV is on and the air intake valve is closed.
3) When the throttle angle is below 60 degrees and engine rpm is above 4200 the VSV is on and the air intake valve is closed.
4) When the throttle angle is at or above 60 degrees and engine rpm is above 4200 rpm the VSV is off and the air intake valve is open.
In other words....
Throttle opening angle equal to or greater than 60 degrees:
When the throttle angle is 60 degrees or greater (that is when the ECU must obtain high output from the engine) and the engine speed is less than 4200 rpm the ECU closes the valve so that intake efficiency will increase due to greater inertia of the airflow. At engine speeds greater than 4200 rpm the ECU opens the air intake valve to prevent a decrease in intake efficiency caused by the increased resistance in the manifold.
Throttle angle opening less than 60 degrees:
When the throttle angle is less than 60 degrees (ie; engine output is low) and the engine is below 4200 rpm the ECU opens the valve so that an equal amount of air reaches all cylinders. When engine rpm is greater than 4200 the ECU closes air intake valve to increase intake efficiency and minimize fuel consumption when the engine is operating under a reduced load.
Whew. I hope that all makes sense and I didn't type it wrong.
7M-GE Intake Air Control Valve System:
Located in the air intake chamber, the air control valve is used to increase the air intake efficiency of the air supplied to the cylinders. It does this in response to the throttle opening angle (VTA) from the TPS and the engine speed signal (NE) from the distributor. The valve is opened and closed by ECU via a VSV and an actuator. This makes it possible to improve engine performance at both low and high speeds.
The air control valve is located in the center of the air intake chamber and when closed divides it into two sections...a front chamber for cylinder numbers 1 to 3 and a rear chamber for cylinder numbers 4 to 6. Closing the valve has the same effect as lengthening the intake manifold while opening the valve has the same effect as shortening the intake manifold.
VSV:
The ECU turns the VSV on and off. When the VSV is turned on vacuum is applied to the actuator which fully closes the valve. When the VSV is turned off atmospheric pressure is applied to the actuator which fully opens the valve.
Operation:
The ECU turns the VSV on and off depending on the throttle opening angle and engine speeds as explained below. (There's a diagram so I'll have to explain it).
There are four possible combinations:
1) When the throttle angle is below 60 degrees and engine RPM is below 4200 the VSV is off and the air intake valve is open.
2) When the throttle angle is at or above 60 degrees and engine rpm is below 4200 the VSV is on and the air intake valve is closed.
3) When the throttle angle is below 60 degrees and engine rpm is above 4200 the VSV is on and the air intake valve is closed.
4) When the throttle angle is at or above 60 degrees and engine rpm is above 4200 rpm the VSV is off and the air intake valve is open.
In other words....
Throttle opening angle equal to or greater than 60 degrees:
When the throttle angle is 60 degrees or greater (that is when the ECU must obtain high output from the engine) and the engine speed is less than 4200 rpm the ECU closes the valve so that intake efficiency will increase due to greater inertia of the airflow. At engine speeds greater than 4200 rpm the ECU opens the air intake valve to prevent a decrease in intake efficiency caused by the increased resistance in the manifold.
Throttle angle opening less than 60 degrees:
When the throttle angle is less than 60 degrees (ie; engine output is low) and the engine is below 4200 rpm the ECU opens the valve so that an equal amount of air reaches all cylinders. When engine rpm is greater than 4200 the ECU closes air intake valve to increase intake efficiency and minimize fuel consumption when the engine is operating under a reduced load.
Whew. I hope that all makes sense and I didn't type it wrong.
So it will open if the IDL contacts open, but less than 60% even below the 4200.
That probably saves fuel.
Thanks for the post.
That probably saves fuel.
Thanks for the post.
Figit090 said:
What you heard probably was the TEMS actuators switching to full firm mode...congratulations! You have a working TPS!!