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I have read several threads for vaccum removal but never found one that actually is a how to.. Can someone point me to some directions on how to do this. What is the benefit of this and will the car run better or worse. I have a bad idle problem right now with my 89 Accord Carb. It starts up about 2000 rpms then raises to 3000. I adjusted the idler and it helped a little but when i have it on for about an hour it starts to choke out..
https://www.3geez.com/forum/search.php
right there
What will this do to the HP?
you should see better pick up.
dont do it if you have smog and emitions tests...Quote:
Originally Posted by mcrowdr
I dont have them where i live..
You will see less chance for a vacuum leak that could hurt carb responsiveness.
You will also see gain in fuel mixture richness, which will hurt fuel economy, although you could tool the carb to decrease richness.
Speaking of that...how bad is it supposed to hurt fuel economy? I did it (except I kept cruise control), no thermovalves or fast idle, and I'm barely getting 20 out of it, even with highway driving. The coil could use replacing, but not badly...and perhaps without the #25 advance, I could bump the timing up a skosh... I plan to upgrade the ignition to Accel coil and such, but it still seems to me like it should be doing a little better than that.
Can the mixture be leaned with just the needle valve screw, or does it have to be the A/F ratio? I ask because on mine, the A/F screw is evidentally not a screw, but just a flat piece of metal, which does not offer much ability to be adjusted without some Johnny 5 magnetic drill finger...
Yes you can try the screw but I was referring to the mains
BTW that flat piece is a block. You need to dissasemble the carb to remove the block to get to the actual screw inside the carb.
You'll need a tiny screw driver, probably like one used in eye glass repair.
You can lean the mains by adding more air to the air correction. There is only one removable air correction jet and that is for the primary. You could try to redrill that one to make it larger and plug the Air Jet Controller ports to prevent air coming in from other sources.
Or you could remove the jet and replace it with a spare jet from a spare carb that you redrilled so you always save one jet as an original.
Hmm I see... I'm actually having a problem that is sounding like it being too lean. My choke return spring is ghetto...throttle return spring to a bracket on the firewall I epoxy glued. The tension is very picky. I adjust it so the choke opener can get it open without much trouble when starting, but when it warms up, it tends to choke (no pun intended) and die sometimes...which I've figured out stabilizes if I push the choke plate shut a little... So if I make the spring stronger, it holds it too much and it won't start...and if I loosen it, it lets too much air in and dies when it's warm... I don't know how you get along without that choke lol.
I'm guessing part of it is my choke opener obviously has a leak. It's got two direct sources of vacuum from that manifold port near it, and it still doesn't quite open it as far as it should. But then again...if it were stronger, it would just be more likely to open it too much when warm again. It's as if I have no suction overall...pos... I replaced the intake manifold gasket too, so that's not it...
EDIT: Well, after futzing with my make-shift choke return spring, I got the car to run reliably...though this thing really needs another pass at the drawing board lol.
Which port on the choke opener are you using?
There is an internal limiter that once the opener moves too far it opens a passage and begins to bleed vacuum.
There is also an internal vacuum passage that gets vacuum from under the carb. I'm not sure if you can apply vacuum to the choke opener when the car is not running... since it might just bleed through the carb and go into the manifold.
I'm using just the two vacuum ports right next to each other. They are both receiving direct vacuum. I just split it with a T and hooked both of them to it.
I wasn't really aiming to have vacuum with the car off... That stupid leak solenoid thing is already gone with the black box. I shouldn't need to do that. It's doing alright now and all, just I can't set the idle as low as I want because it's fickle. Because of the aforementioned choke issue (so I gather anyway), the car starts up and idles in park or neutral around 1,000 rpm...but when it warms up, it goes up to 1,500. If I set it lower, it tends to want to stall when coming to a stop...sometimes it picks itself up, but I can't have it coughing out all the time, of course....unless there's something wrong elsewhere... I do suspect the alternator is going, but I'm actually going to start a thread in the basic technical section because it is not carb related....:-P
I do not know absolutely that the choke opener isn't going as far as it should. I am simply judging by the engine stability relative to the position of the choke plate.
