FC3S_Bat

I recently bought a 1990 FC, yes it is my first rotary, and noticed it stayes in "warm up" mode longer than it should, even after engine was warm, which lead me to finding out that theres no thermostat in it, I been going back and forth and taken different advice from people as to whether or not I should install one, keep in mind this isnt a project or drift/racing car (yet) im mostly cruising and occasionally racing or speeding a bit, sometimes I go to work with it, and I will like to know if there is a specific type of tstat I could buy that will fit the engine's current needs and keep my temp at a safe level, also what is the temp rotaries work best at? That may also lead me to the right choice...

eage8

iTrader: (9)

just put a stock thermostat in it and be done with it.
The better version of the 2 stants is fine:
https://www.amazon.com/Stant-48438-X...CL4/ref=sr_1_3
or just get a mazda OEM one.

if you really want to you can get one that opens slightly sooner like this:
RHDJapan : Sard Low Temperature Thermostat - FD3S

misterstyx69

iTrader: (142)

stock thermo..by far the best..all others can eat crap

Inside car temp?....I got a internal temp reading of 145 Fahrenheit once with my Infra red gun..Seriously!..Black interior in the summer!

FC3S_Bat

I ordered an oem one straight from mazda, should be in thus afternoon, that one is supposed to allow the engine to run at 180° which seems pretty regular, ill let you guys know how it turns out, thank you for the links!

misterstyx69

iTrader: (142)

If you want some reading...look up Jiggle pin using search.
Also guys used to drill a hole in the base of the aftermarket thermo's to aid the circulation.You'll read about that too if you hit some threads about thermostats.
Trust me,a lot of good stuff..informative..brain clogging but informative..lol!

FC3S_Bat

So I just installed the stock t.stat and it still idles at 2k, the temp gauge went up faster and kept itself below mid level, I unplugged a wire that runs thru the throttle body and it dropped to 1k, however it choked a bit when I tryed to rev up the engine, what am I missing here?

eage8

iTrader: (9)

I may be mis-remembering, but the only wire that goes to the throttle body is the TPS (throttle position sensor). what did you unplug?

I would look at the Factory service manual (google rx7 FSM) and try to diagnose what causes a high idle. Most of my knowledge is in turbos, but there are only a few valves that can raise idle. BAC, AWS, and one more I forget the name of.

also, have you tried just blipping the throttle? does that fix it? RX-7s are designed to raise the throttle on initial start up with the AWS.

FC3S_Bat

It is in fact, the TPS wire, but I've read that disconnecting it can raise the amount of gasoline that flows into the engine, risking engine damage/blow ups.....?

I mean other than the facr that the car stays at 2k everything else is fine, I feel like the car breathes and runs better with the tps plugged in, its just that high idle....

eage8

iTrader: (9)

How long does the idle stay at 2k? Does it go down if you blip the throttle?

You need a tps. It won't run properly if the ecu doesn't know what the throttle position is.

FC3S_Bat

It stays up for a good 30_45 min even after driving it for that long, I adjusted the throttle and dropped it back to 1k, with the TPS plugged in, but I feel and smell that its burning too much gas... could it be that I have a bad o2 sensor and the previous owner tryed to bypass it by removing the thermostat and raising the idle speed in order for the engine to burn off the extra gas going into it?

KansasCityREPU

iTrader: (9)

Aren't there procedures in the factory service manual for checking everything in your questions? Might be a good place to start.

ST1

A 180° thermostat doesn't allow the engine to run at that temperature. It doesn't begin to open until 180°, thus preventing coolant from getting into the radiator until it is hot. Normal operation should be around 200-220°.

FC3S_Bat

you are correct! ill be buying myself one soon since the car didn't come with one, plus I like reading everyones perspective, specially if they are experienced with rotaries.

FC3S_Bat

the car doesn't have a cat, and its got racing beat exhaust on it which looks like its running straight down from the headers.... maybe that's the gas smell?? lol
also after messing with the throttle earlier today and bringing it down to 800-1000 rpms on idle im pretty satisfied, it takes a min for it to begin idling normally when first started (wants to shut down) but after a few revs it seems to catch itself
you've all been very helpful.

KansasCityREPU

iTrader: (9)

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