importsown

Hmm, never ever heard of that in my life, and even though "its known to happen" i would extremely doubt that. Even if your front brakes are on fire the rears still see much less use and therefore much lower temps. I guess it IS possible, but i would say it is highly unlikely.

Valkyrie

It's mentioned in the FAQ's of all the track event and driving schools I've looked in to.

idsigloo

Are you talking about the cold-start assist that puts coolant into the intake during freezing temperatures? That is commonly removed.

Enthu

iTrader: (1)

I personally tap the throttle right away to get rid of the 3k start-up idle. The I let here idle for a minute or 2 before driving unless I am in a hurry. Also at shutdown I rev the engine up to like 4k rpm then kill the ignition to prevent an flooding.

ultrataco

iTrader: (2)

???
Coolant injected in the intake? I have no idea what this thing is. I don't think mine is removed.


I have no idea what a cold start cam is... Is this why my car idles high ~1500-2000 when it's cold and slowly drops to normal idle (~750) by the time it's warmed up?

...and i don't know what thermowax is either.

sigh... I have a lot to learn about these cars.

NZConvertible

The sub-zero start assist system is totally different to the thermowax. The thermowax is what raises the idle to 900-1000rpm until the engine warms up.

Yes, but it shouldn't rev that high. Someone's probably messed with the adjustment screws.

The thermowax is what actuates the fast idle cam (cold start cam is the wrong description). When the enigne is cold the fast idle cam holds the primary throttle open a little bit so that the idle speed is raised to prevent stalling. The thermowax has coolant flowing through it, and as the coolant warms up the thermowax moves the fast idle cam off the throttle linkage, allowing the primary throttle to close and the idle speed to drop to ~750rpm.

Grab the FSM and start reading. You'll learn a lot. Start with page F1-36, which shows to how to set the thermowax properly.

ericgrau

iTrader: (1)

Startup: Just drive. Keep the load low until it warms up.

E-brake & racing: Rotors almost never warp. BUT the brake pads deposit material on the rotor when hot (they are designed that way). If you set the e-brake after a track day you'll get a (invisible?) brake pad shaped spot on your rotor, which will cause the brakes to vibrate later on. The rotors feel "warped". To break in new brake pads: Brake lightly from speed to 5-10mph (don't stop!). Repeat a few times except do it a little harder each time. i.e., brake hard the last time. This will evenly deposit brake pad material. Also, don't hold the brake pedal down when stopped after heavy braking.

mikaz

um, what? Is there something wrong with what I said?

Aaron Cake

iTrader: (1)

The SUB ZERO ASSIST is the tank of glycol mounted to the firewall near the charcoal canister. It's designed to inject a small amount into the intake to help with cold starts (presumably to de-ice and help the engine build compression). It's useless, never worked, and Mazda issued a TSB to dealers to remove them.

The COLD START THERMOWAX and CAM is a small mechanism on the throttle body designed to keep the throttle plates open slightly until the car warms up. This is responsible for the decreasing 1500 RPM idle as the car warms. Without it, driving on a cold engine can be VERY annoying as the idle is unsteady while the car is cold. Modern cars do this electronically with the idle valve.

For some unknown reason, people like to remove the thermowax/cold start cam. The result is a car that is a ROYAL PAIN IN THE BUTT to drive until it warms up.

SpooledupRacing

IMO (and I'm a newb at rotarys) I let the cold start warm the car up for th e15-20 seconds then let the car idle a minute while I put my belt on and adjust the radio but after that its all fun.. now I DO agree u SHOULD let the car cool down for a minute before u turn it off ESPECIALLY in a turbo vehicle..

see with turbos if u dont let it cool down the oil will coak in the housing and cause problems with your seals and bearings.. now with a N/A car I just say it is good to allow the engine to cool a touch and rev down before u shut it down

Dave

ahabion

ah yes i was... nvm then.

ra ra rotory

This is not preventing flooding, unless your running carbed 350 chevy under the hood of your Rx7.

ericgrau

iTrader: (1)

Rotary Performance (rx7.com) claims that Mazda says to rev to 3k for 10 seconds, drop to idle, then shut the car off. This is supposed to prevent flooding in a car that isn't warmed up. Does it work? I dunno, my '7 never floods regardless.

sykminded

yeah, for turbo, but if you have an N/A you're just wasting gas letting it idle and "cool down" unless you've just been pushing the **** out of it. If you were just driving to work and you're parked, just turn it off, lock the door, and get on with life.

NZConvertible

This does not apply to water-cooled turbos unless you just been driving very hard. Extending idling after normal driving does nothing except waste gas.

snwboard8907

What is the FSM? and also where can I get one. I got the Hayne's, but it seems like there's better knowledge of the 7 in the FSM that Hayne's doesn't have. I've only had my car for about 2 months, and I want to start gettin more power out of it. It's an '86 with lsd and the 15" wheels like the gxl, but no sun roof, rear wiper, no power anything. The guy I bought it from said it was gxl, but after doin some research, I'm not to sure of it. Also, on start-up, car will rev to 3000, then drop down to around 800, and stay, but once i tap the gas pedal, it will go up to 1500 then drop steadily till car is warm. That's all normal, right? Thx

Black Knight RX7 FC3S

iTrader: (7)

I usually let the car idle for a certain amount of time depending on the temperature.
if its more then 85F I just start the car and let it idle for a minute and then off I go.
50-85F I let it idle for about 2 minutes
anything below 50F I let it idle till it warms up to operating temp.
I follow this strict rule in everycar I drive.

In piston engines I also have to factor in the weight of the oil. The thicker the oil the more I wait, since piston engines have alot of movingparts that require lubrication, and thicker oil doesnt flow that well till its warm.

Rotarctica

I let my car warm up until it reaches the first 'normal operating range' mark, at the very least. I like to have all the parts and seals lubricated with warm oil...I do run 20w50. It's getting colder, so I'm going to wait a little longer. Call me obsessed, call it unnecessary to wait that long for the damned car to warm up...you'll waste time typing it.

I usually wait close to a minute after driving to shut it off. I use a sun shield to protect my dash...so I take off my seatbelt, roll up both windows, close the sunroof, put up the sun shield, grab my wallet, grab my cell, make sure the antenna is down and THEN shut it off.

Slow Rotor

I cant belive that some ppl actually said there is no need to let a stock rx7 warm up (over 80% of damage done to cars is done in the first 2 minutes of driving) That is the main killer of seals in these things. Dont let it sit there and warm up that is just stupid it will warm up the engine and nothing else just take it easy until its at operating temp that way your gearbox warms up as well. As for turning it off you should let it run for a while expecially if its a turbo, your seals will last alot longer.

Aaron Cake

iTrader: (1)

Factory Service Manual. It's available for download in the FAQ.

You'll waste more time in all that unnecessary warming and cooling. Not to mention fuel, the environment, money, the engine, etc...

I run 20W50 as well, but as soon as it starts to get cool I switch to a lighter weight as is common practice...20W50 when it's cold is nearly solid at start up and VERY bad for the engine no matter how much you "warm it up".

sykminded

my thoughts exactly.

Rotarctica

The lowest temp it'll ever get here is 32 or so degrees farienheight (SP?) 20w50 should be okay to that point...but if it gets to freezing, I won't be driving my RWD car. haha

NZConvertible

Exactly what seals are you talking about? And how is idling going to make them last longer?

Boostmaniac

I don't know, the idle cool down seal maybe

rx7man13b

For the original poster, listen to Aaron. Hes one of the most knowledgable ppl on this site. Even though he hates my carb. lol I let my car idle for about 7 min. then drive