1stGenerationGap

could someone tell me what the idol is suposed to be in a 12a motor. mine just feels too low for the car

Jozay721

i think its 750 manual, idk automatic, but if im wrong about manual just wait for another opinion.

no_name

It is 750, but I don't think anyone on this forum has a car that idles right at 750rpm lol.

Mazda12AGS

If it is low drop to your knees and thank God, mine idles anywhere from 1000 to 2000 depending on the weather and the mood the cars in that day.

Mr.Snakey

this thread brings up a good idea to check what rpms im idoling at when i get it runnin, thanks haha

Jozay721

bridgeport,streetport,and peripheral ported engines get a different idle naturally right??

Mazda12AGS

I dunno about streetport, but bridge and PP are horrible idleing from what I have heard.

Jozay721

o thats good to know,does it idle surge up and down or its just high?

1stGenerationGap

im at like 500 or a little under and when i start it cold it stalls like 3 or 4 times and has a problem to get the rev up, when it FINALLY gets warm it is fine but still idols at 500 or below

Jozay721

do u pull the choke when u start it?

Mazda12AGS

Does it idle like **** at 500 or does it idle good. These cars just always run like crap untill they are warm.

MosesX605

I've got mine set at ~800 right now. It's rock solid once it's warmed up. It'll idle at 700 but it misfires now and again at that RPM.

1stGenerationGap

yes i pull the choke when i start it. and it kinda sounds like it may bog out. i will get a video in the mornin of it for ya

Jozay721

cool, that will help a lot, for all of us

Mazda12AGS

Hell the only time mine ever idles that low is when i am about to run out of gas.

1stGenerationGap

lol nope i have gas for sure lol.
but ya the video is on its way either in the mornin or the next day

BigJeff

I know Sterling idles his at about 650, I'm gonna tweak my carb soon and try to get down there, I'm at about 950 right now.

novaboy009

Check for vacuum leaks. Mine idles at 950 normally, but it'll die down to about 500 or 600 when the choke first pops back in or when I turn the headlights on (alt drag pulls it down). I believe it has a leak in one of the 1000000 lines in the engine bay.

Kev

Tranquil

iTrader: (1)

Was I the only one that thought this was going to be a competition on who has the best looking FB engine bay? 12A Idol instead of American Idol?

hmmm, I think I'm going to go check my idle late on today, we just got it running last night.

Marek

iTrader: (2)

Tranquil you bugger I was just about to make that comment your 15 minutes ahead!

Tranquil

iTrader: (1)

hahahahaha! go me!

Well today I tuned my carb, since I had only gotten my car running beautifully for the first time ever.

The lowest I was able to get it to idle was 1000RPM, no less. At least its a steady RPM and doesn't bounce around. I was merely playing with Idle Mixture and Idle Adjust screws. One of these days I'm going to get a vacuum gauge and wideband.

MattG

iTrader: (2)

What I would do for a smooth Idle.

I have a street port 12a, and for some reason I can never get that thing to idle smooth.

DeRFmAn

I don't think ported engines are ever going to idle right. Mines unported and its between 750-900rpms. Its steady when idling.

PaulFitzwarryne

500rpm is far too low when warm. Between 650 and 750rpm is best for a stock engine.

As you modify and port, then the idle revs need to be increased. A Bridgeport needs around 1200-1500rpm to be happy, but then you are not really interested in idle anyway. I have seen a hot PP which needed a minimum of 2,000rpm.

One of the few problems with a light flywheel is lack of smoothness at low revs which is traded of for high rpm performance. The reason Mazda went for such a heavy stock flywheel was to keep the engine turning over smoothly at low rpm so 650-750rpm was possibly sitting in traffic.

cdrad51

I used to be able to idle my sp 12A at 750 rpm when everything was the way it should be, i.e. mixture, timing, no vac leaks.