How to properly start-up your mazda
 

Hello I am looking for the best strategy/procedure to properly warm up a carb'd 12a . Car is completely stock. Where should the choke rest when I first fire it up(RPM) and should I adjust that before I put it in Drive. Nt a huge fan of slamming it in Drive at high rpm (iits an automatic). If this is a frivolous question educate me! Thanks. Car starts up fine just not sure what the best is and whats too much. When its really cold outside I usually have it at 2,000 rpm and then i will here the fan clutch adjust then I lower it and drive away.

Hello,

So the car will start on full choke anytime. If you leave it idling as it warms the rpms will increase. I manually push my choke in a little at a time listening to the engine to tell me how far.

Depending on what year your car is, it may have an auto choke, in which case you can use full choke, turn the car over and it will pull the choke in itself. Once it does you are ready to drive. However, i think it does this too slowly and i still manually inch mine in by ear.

In warm temps, the car should turn over with no choke at all.

Bottom line, pull the choke, turn it over and adjust by ear. If it starts stumbling you pushed it in too far and then just pull the choke out a little.

My rule is never to drive away until the choke is fully pushed back in, then you will be at regular idle ~800 rpm and will have no issues. Always pays to fully warm up a rotary before you drive anyway, as it helps prevent flooding and other issues.

Hope that helps and is not offensively basic lol!
Tom

All first gen rx-7s are auto choke in stock configuration.

1. Pull choke out all the way.
2. Start car
3. Wait for choke to release itself.
4. Drive.

Never turn an rx-7 off without it warming up completely. This means the choke with pull itself back in. The reason for this is because rx-7s can flood easily if not warmed up and then shut off.

And then you open up a whole new can of WORMS :lol:

I'm a bad speller. I can't even type and I'm a programmer.

I use it for occasional casual daily driving getting to work in the morning. I usually never give myself time to wait for the choke to pull it self in when i fire it up. It usually "clicks in" a few minutes into my drive.
The way I see it the darn car will rev to over 4k if i pull the choke out to a far distance than what im been accustomed. I feel like im gonna ruin the car. Is it possible that I have a stuck open thermostat and the car isnt warming up efficiently ? Which I dont mind. This car has leaky intake manifold orings. Did the radiator myself and the thing is cooler than an ice cube going 75+ on highway : l typical pressure on the hoses. Have the intAke gasket orings and freeze plugs for the manifold but lacking the confidence to remove the intake and replace everything back together. Usually working on it on the street. Rats nest is there in all its glory

I start all of mine without the choke after a couple pumps of the accelerator and once it runs for a couple seconds and builds up oil pressure, I will pull the choke out a little bit and let it run about 2000 rpm to warm the engine. Pulling the choke and sending a cold engine soaring to 3500 rpm right off the rip just doesn't sit well with me. The choke will return on its own if you allow it to. Its an electromagnetic choke and does work quite well.

Great thats what I perform. Couple pumps see the gauge pressure respond and then go with it. Manage the choke. I do notice that the car is cold it will bog and even stall if i am too quick with the throttle as if the car like Its fuel injected. If i swing to fast it will stall from a stop even when warm. More when uphill. Haven't tampered with the car or much else other than spark plugs oil change. Anything I should def consider maintenance wise? I have the carb kit bit don't think I need it really. Just wanna preserve her as much as possible. Causual daily driver

Double check your timing and the float level - should be 1/2 way up the bowel sight glass front and rear. Quick and easy to do.

FYI, before you think about rebuilding your carb - my father in law and I spent ages trying to track down the source of a slight hesitation/bog at light throttle. Turned out that the issue was simply that the car had not been run enough and just needed some use!

Several cans of seafoam and a few tanks of gas later and it ran perfectly and still does! :icon_tup:

I am assuming there must have been some varnish or gum or something in there that just needed flushing out.

For the last 28 years, my process has been:

If dead cold and not started for several days or more:
1) Ignition on. Check battery voltage.
2) Wait for pump sound to change pitch, indicating fuel lines and bowls are full.
3) If outside air temp below 95, pull choke fully. (If hotter, 2/3 choke or so; upwards of 100, I don't normally need any/much choke)
4) Switch to start position; if no fire within 5 seconds, ease choke or crack throttle slightly.
5) As engine lights, release key.
6) Allow RPM to rise for a second or two; if settles above 2500, ease choke to around 2000-2500 RPM.
7) Drive (soft-releasing clutch while cold) or wait for choke to release as temp gauge rises off of bottom pin before shutting off.

If the car's been run in the last couple days, I can generally skip 2 & 4.

Mine is hard to start in the cold the revs never go up with the choke on. It like I need to adjust the fast idle for cold starts, I need to look into it...

I have to adjust my idle mixture here between spring/summer/fall as the air temp changes by 30+ degrees in that period.

Only 1/4 to 1/2 a turn but really improves the idle.

However pulling the choke is like pressing the throttle, your revs should climb regardless of temp. You sure your choke cable is connected and functioning?

Tom

Wow there's some intense people here.. Pull the choke out and start the car. I personally adjust mine to about 2000 rpm and drive away. No need to sit there wasting petrol.

I give a couple pumps on the accelerator, pull the choke all the way out and slowly push it in while cranking. If I get it pushed all the way back in before it fires (5-10 seconds) I give the starter a break and repeat the process. If the car has sat for a while, it normally takes two or three cycles. Once it fires, I'll adjust the choke knob to set the idle at 1,500-2,000 RPMs. Since I don't daily drive mine (pleasure use), I'm not usually in a hurry to get anywhere with the car and I like to let it warm up enough to let the choke automatically shut off before taking off.

Pump the pedal a few times, pull the choke out completely, turn the key, push the choke in until idle drops to 2,000 rpm, drive off gently. No full throttle or revs above 4,000 until the choke auto retracts. Occasionally, if the car is surging forward or revs high at a stop sign I will push the choke in manually a little more. Waste of gas and time sitting parked waiting for temps to go up, just drive it gently.

My choke never does seem to auto retract... it retracts when the power is turned off, of course. Any thoughts?

Might do a search, it’s been covered a few times.

someone help me figure this out, my 79 SA 12a is bone stock.. when i first bought it couple years ago, the automatic choke worked fine.. i would pull, start it up, let it warm up & the choke will gradually pull itself in.. then i would drive... now the choke wont stay engaged, i have to hold it up for the complete warming session thats like about 8 to 10 minutes then drive... im tired of baby sitting my choke..
how can i resolve this problem?... any tips or ideals will help..

Check the water temp sensor in the back of the water pump housing. Searching would have found the answer.

What should i look for?.. a disconnected sensor?.. broken wire?.. never knew that would have something to do with my choke.. but i will give it a shot tomorrow.. Many Thanks Kansas City.:)

The sensor is large with a two prong connector. The two wires that connect to the sensor break very easy,

https://cimg5.ibsrv.net/gimg/www.rx7...131e9a2dc7.jpg

Usually warm mine up at 2 - 2.5k . I have no mechanical basis for this but the car seems happy! >.<

Am I the only person that pretty much immediately starts driving?

Jump in, choke on, start, ease choke back to about 1600 rpm and pretty much set off, usually give it half a minute just to let some oil circulate.
Progressively let out the choke as it warms up, but generally within a few streets it off completely.

I think most folks here, now own and operate these cars as occasional use, "fun" vehicles. This changes the mindset some, to where even starting it up is kind of a ritual. If you daily drive a vehicle or look at it as just a machine to get you from point A to point B, I think you're more apt to click and drive.

Its my 'fun' vehicle, I just happen to use it a lot as well, but I just don't think that sitting & idling till it gets fully warm is doing it much good, I'd be happy to do that if I thought it was any benefit.
But as long as the oils had half a minute to circulate then IMO its better to set off immediately, and drive gently until up to temp, the car warms up quicker as well.