Hey,

I have a totally smooth idle--but at 2500 rpms. What is going to cause an idle that high? When I start the car it idles around 1500 (that high idle is probably because of the vacuum lines). But as it comes up to normal operating temperature, the engine idles higher and higher until finally it stops at about 2300-2500. I checked some of the more obvious vacuum hoses (the MAP sensor and the hoses on the idler controller), but I can't imagine a vacuum leak causing that high an idle.

By the way, I have no mods at all. Someone give me an idea of where to begin.

Thanks,
Clint Fralick
Struggly@hotmail.com

 

After not finding anything obviously wrong, have you tried adjusting the idle down? Cold weather causes the idle to go up after warmup due to the more condensed air.

 

It could be the intake or the sensor

 

Which sensor? Thermosensor?

And what about the intake? I checked for leaks in the obvious places with carb cleaner.

Clint Fralick
Struggly@hotmail.com

 

Try inspecting the Accellerated Warm Up System Solenoid Valve. (AWS). Possibly, the solenoid is bad and it is just not closing causing the idle to increase instead of decrease due to the increase in bypass air to the intake. Pages starting at F-81. There is an online manual if you do not have one. Email me if you need the manual (mccreary@cove.net)

Tim

 

Thanks Tim. I'll check tomorrow. Any other ideas?

Clint Fralick
Struggly@hotmail.com

 

Make sure your dashpot is not stuck. You should be able to push the dashpot buttoon down and be able to see it return slowly.

 

I'm kind of new at this, but I might have an idea what your problem is. I'm assuming you have a manual transmission. If you start your car in neutral, then the car will start out at a idling at a very low RPM for about a second or so and then it will go up to somewhere around 2,500 RPM. However, if you start the car in first gear and let it idle in first gear for a few seconds and then shift it into neutral to let it warm up then the RPM's should stay pretty low.

If for some reason you do start the car in neutral and you notice the RPM's are getting really high very quickly, then put the car in first gear and blip the throttle. By blipping I mean for you to simply hit the gas really quick (enough to cause the RPM to go up for a second) and the car Tach should slowly read lower and lower RPM's until it reaches a normal idling speed. I think that if you do this right it should be idling somewhere around 2,000 RPM or a little bit lower.

Assuming this is what your problem is then the High RPM's you are getting are part of what Mazda calls it's quick warm up settings. I think that Mazda did this so that the car could warm up as quickly as possible. A lot of people don't know to let a turbo charged car idle for a while before you go anywhere and once you arrive at your destination. I think this was Mazda's attempt to save the engine from those people who knew nothing about turbo's. Let me know if this helps.

- Cody

 

VTAOE: what you're describing is known as AWS, or Accelerated Warmup System. Good call on that though, someone just got to it before ya

 

THanks for the replies. I know what the accelerated warmup system is. I do not have high idle until the engine reaches normal operating temperature.

SpooledUP7, where is the dashpot located. I do not know my way around this engine bay very well yet. I've barely owned the car for a month. Is there a diagram in the service manual?

Thanks,
Clint Fralick
Struggly@hotmail.com

 

The dashpot is sort of like a throttle stop with a cushion. It is a small canister thingy right next to the throttle linkage. Yes, the manual has a section on the dashpot.

 

Also check your throttle linkinge it maybe stuck when its cold hanging it up causing your problem.

 

*linkage* sorry