here's the problem. found two vacuum leaks, replaced the hoses, now it won't idle at all, before it would sit at 1000 rpms. My mixture screw and idle speed screws are way off. Where do I start? read sterlings post on how to tune a carb, but thats for a car that will idle, this one just dies. If I pull out the choke, it will sit at aboutyt 800 on its own, push it in and it dies instantly.

 

Double check that you've put the right hoses in the right places.

Start adjusting those screws. In Sterling's FAQ, he gives the amount of turns to put it at 'around stock,' so start there.

 

how the hell do you get to the faq? hit the link at the top and its just about postings and stuff.

 

It's in Sterling's website, which I don't know off the top of my head, but it's in the faq O_O O_o

 

I start with the idle MIXTURE screw turned all the way in, and then backed out about 2 1/4 turns.

Then I turn the idle SPEED screw in a ways so that the primary valves look to be about 1/16-1/8 inch from the edge of the throttle body.
This sets the idle speed well past 2000 rpm, at which point the engine will run no matter how screwed up the idle circuit is because it's not even using it.

Start the engine and adjust the idle SPEED screw down until the engine begins to hunt or chug.
Then adjust the idle MIXTURE screw until it sounds better.

Kepp repeating this process down to wherethe idle is good and solid. It should be able to get down to 600 rpms with no problems, but it's sort of delicate when it's that low, so when you put it in gear or ome to a stop it might die. That's why you want the idle up to 750 rpms.

Remember-
Make sure the engine is warmed up fully (Usually not a problem when starting from NO idle!)

and be sure to give the idle circuit a second to "clear it's throat" when you make changes. Sometimes you can change the mixture screw and think it's steady and you turn around and it stalls. So make the changes slowly and incrimentally, and give a minute to wait for it to take full effect.

If you can't get it to idle after an hour of putzing like this, then something's wrong.
You either have a leak, a fuel pressure problem, a super dirty air filter, or a linkage binding problem.

It is NEVER, u]EVER[/u] a float adjustment problem!

 

thanks, problem solved, runs like a champ now.

 

Hi! I need to do the same to my 1984 RX-7. I've found the idle mixture screw but where is the AIR ADJUST SCREW for the Carb? I only see the one screw at the bottom of the carb on the driver's side.

GIINK