flight_of_pain

so i changed the plugs, wires, air filter, and fuel filter the other day and started premixing. once i restarted the car it idles so low its on the lowest mark on the tach. i can distinctly hear each exhaust pulse, and its just barely running fast enough to keep going. has anybody else had this happen? what should i check first?


isaac

Bolox

why is this bad?
if its idleing really low and staying there i thought it'd be good?!

-Cheers

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iTrader: (1)

mine idels at 1000 to 1100 rpm's i have not had any problems with it dieing out at all . seem to run just fine.

Northern 7

iTrader: (3)

I think if he's idling at the lowest mark on the tach (2K), it's a bit too low.
Assuming you have already tried to adjust your idle, I'd start by checking for vac leaks. You never mentioned what car you have (12a / 13b) - that would help.

85rotarypower

The lowest mark on the tach is 200 rpm. Thats damn near impossible. I think your starter spins the engine at that speed. I can't conceive the engine running at such a low rpm. Are you sure your tach works?

mwatson184

I've messed around before and got the idle right around 400 rpm, but 200...that is something else. Just adjust the curb idle speed adjustment screw to bump up the idle.

Marques

Tsi_Xtreme

if you have a 13b engine I would adjust the throttle body sensor. Not sure if 12a engines have the same senor or not.

http://www.racingrotary.com/tps.htm

85rotarypower

No they don't. That sensor is strictly for the computers use, which also controls the idle of a GSL-SE. I don't think the computer would allow a GSL-SE to idle that low. It would just find a problem in the system and either shut the engine down or try to compensate.

RitcheyRch

Mine is in the local shop trying to figure out why it is idling so low. I rhad the carb rebuilt a few months ago and was working fine and now all of a sudden is idling at 200 rpm's. I even hooked up another tach to verify is idling at 200.

flight_of_pain

sorry but it is a 12a, ill check for vac leaks next, but i believe the tach is ok because it still reads at the same rpm vs speed points(while driving). it is bad because if i get on it off idle it dies.

didnt see your post until after i posted RCH, but that sounds the same. let me know what it is if they figure it out.

85rotarypower

Do you know how to tune the carb at all? If you do then you could probably just bump up the idle to the 750 its supposed to be.

I should also mention that vacuum leaks will not cause it to idle low. It does the exact opposite in fact.

mwatson184

There is a single screw that will raise the idle, very simple. Adjust the idle speed with that screw and you will be ready to go.

RitcheyRch

I have raised the idel up numerous times but after a few days it drops back down.

Northern 7

iTrader: (3)

Well that's totally not true -
A really serious vac leak will lean the motor out to such an extent that it won't idle at all and if it does, it will be very low and usually rough - bad leaks will cause lean misfires that will barely ignite at all and drop your idle like a rock.
I should mention that I assumed this guy has already adjusted his idle - if he can't get it to climb with the idle screw, many times it is caused by bad leaks. I've been there.

rototiller1

adjust the slack out of your throttle cable, then make sure the jam nuts are tight

RitcheyRch

Jam nuts are tight and cable has been adjusted. I guess will need to double check for vac leaks.

rototiller1

vac leak will not cause a low idle

rototiller1

vac leak will not cause a low idle

rototiller1

vac leak will not cause a low idle

rototiller1

sorry, my computer said the site was not responding

rototiller1

check the secondary air valve for being partally or fully stuck closed, because it may be running on one rotor at idle

bouis

If you don't believe that a vac leak can cause a low idle, try removing the cap from the bigass nipple behind the shutter valve where automatic transmissions hook up.

Northern 7

iTrader: (3)

Thank you
- nobody listens anymore

sweetege

Ok i did'nt want to start a new thread so... i found the air adjust screw the thing that you can see when you look below the carb from the drivers side and messed with that. now this might sound stupid but which way is lean and which way is rich cause my car sometimes floods under heavy acceleration. And the second question is where the crap is the idle adjust screw??????? i looked for it but all the piece of crap vac lines are in the way SOMEBODY HELP please. thank you.

85rotarypower

Turn the screw in to lean it out and out to richen the mixture.

As for vacuum leaks creating a low idle, I guess it is possible. It does make sense, I have just never seen a vacuum leak create a low idle.