hyperion

iTrader: (2)

After thinking about this for some time, I am a little perplexed at why Mazda chose to put both the Accelerated Warmup System (AWS) and the Fast Idle Cam on the FD.

The AWS essentially augments the existing throttle bypass by allowing more air to enter the primary intakes. This pushes the revs higher, allowing the car to warm up faster. Many modified cars either plug or remove this feature.

The Fast Idle Cam props the primary throttle body open just a little bit until the coolant flowing through the throttle body heats up the wax pellet enough to push on the cam and close the throttle body. But the effect of this system is to raise the RPM higher--just like AWS! I understand that the reason the throttle body is heated is to remove ice from the system during cold start, but why tie the warmup of the TB to the angle of the primary throttle?

Why did Mazda employ two (very complex) systems to do what could have been more easily accomplished by the idle stepper motor? I mean, they could have just programmed the ECU to watch the water temp and change the idle settings. It just doesn't make sense.

Any thoughts?

-ch

tekno62

Cam?

JONSKI

I think the AWS assists the ISC. If you remove the AWS (as I did), the car will still rev to 3krpm on a cold start. Also, ever since I removed the AWS, the car has had trouble idling under load (A/C, headlights, etc.).

duboisr

Just remove the AWS and the hot wax rod and the cam . Remove the water lines as well .Before doing the work look at the water heat jacket all around the throttle body , HAHA there is not one . the compressed air is hot as no iceing will happen if you boost alittle in normal driving . Has any one really had iceing problems ? My mechanic does these things plus more to the throttle body and all have started well and idled in the Tennessee weather at least . Just think you can loose three rubber water hoses six clamps plus all the other stuff .

FDjunkie

Here's my list of items affecting idle rpm. Notice that the AWS (#6) operation is binary; either its open or closed. Where as the Fast Idle Cam (#3) can have an infinite range of positions. Therefore, (and ignorying the PITA AWS) as your engine warms up the idle RPM SHOULD gradually decrease until it reaches its normal hot idle speed.
[list=1][*]Throttle plate stops - Physical limit. Setting generally made only during production to determines the absolute minimum closure point of each throttle plate and thereby prevent long-term wear that might cause increased air leakage.[*]Air bypass adjustment screw - Physical adjustment. About a 3/8 inch diameter slotted brass screw whose head is visible on the throttle body below elbow mounting area and slightly toward the firewall. Manual setting that controls how much air bypasses primary throttle plate and used to set the fully-warmed-up idle RPM.[*]Thermal wax/fast idle cam - Thermal range. Intended to increase idle speed based on the relative temperature of the throttle body. Has two adjustments, one for matching cam position to an actual temperature, and the second for setting the amount of RPM increase at that temperature. Heated by flow of engine coolant and should completely loose any effect following warm-up.[*]Deceleration dashpot - Slows rate of throttle closing. Designed to slow the rate at which the primary throttle plate closes the last few degrees, but should not result in more than a 1-2 second delay in full closure. Adjustable but rarely needed following correct installation.[*]Idle air control valve - Closed loop controlled by ECU. Responsible for adjusting idle RPM to offset electrical loads (see below) and A/C compressor. It also feeds in air during engine deceleration to prevent afterburn.[*]Automatic Warm-up Solenoid - Binary Thermal. ECU controlled valve that provides a simple open/closed operation. When open passes a fixed amount of additional air around throttle plates during initial cold start conditions that are generally thought to last only 5-10 seconds. Effect is bypassed on cars with manual transmissions by placing transmission in any gear before starting engine.[*]Electrical Load Control System - Electrical load. Monitors several electrical circuits and if one or more shows active, the RPM is increased by the IACV (see above). Thought to have no throttling action; just normal and high, but this has not been fully verified. Does it increment in steps with multiple electrical loads?[*]Vacuum leak(s) - Uncontrolled amount of air. Any uncontrolled source of air leakage can affect both idle speed and idle A/F mixture. In general they cause the idle speed to float up & down over several hundred RPM. Small leaks tend to slightly increase idle speed for 5-10 seconds followed by a stumble, while larger leaks make the idle speed lower than normal and very unstable. Effects can vary greatly depending on the amount of air leakage, engine condition, and state of tune.[/list=1]

efiniracing

Can anyone tell me where the aws is? I'm trying to put a block off plate there for going non sequential.

jr

To answer the original question, the AWS was intended to get the pre-cat up to temp quicker to help cold start emmissions. The fast idle cam is just there to help the car idle during warm up like in any other car.

RX7SpiritR

iTrader: (1)

fast idle eccentric shaft.....lol!

JONSKI

The driver's firewall side of the UIM.

RX7SpiritR

iTrader: (1)

ahhhhhh, now I C!

efiniracing

So should I get rid of all that stuff? I'm going non-sequential, i don't need to pass emissions and I'm running pfc.

If I pull everything, what do I do w/ the black hose that is connected to the aws pipe?

Team Belligerance

Jonski, great example.

jr

Pull it out and cap the hole on the elbow. I used a rubber stopper from the bottom of a folding chair and a hose clamp. If you get the Greddy elbow later on it won't have the hole anyway.

adam c

iTrader: (2)

WINNER!!!!

Ghetto mod of the week

Tattoovido

WAAAHAAAAA!!!!To each their own.thats a good 1