Carb idle adjustment

The Haynes CJ manual is excellent! The carb and wiring stuff it right on.

That said, if you have the 83 with no O2 sensor, the computer has gone into limp home mode and has clamped down on the timing and carb mix.

You should disable the computer and set it up manually. It will give you at least 10 mph more in each gear easily and your gas mileage will go up. I can walk you through a basic carb mix if needed to dump the computer.

Here is a decent link on the computer dump:

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The throttle has the idle screws on it.

The outside one that hits the round center rod is the curb idle.

The next one in that hits on that plastic step set that turns when the choke closes is the fast idle. When fully warmed up, you set that stepper up to the second from top step and turn the screw until you have

1750 rpm.

There is maybe one more screw up top of this and it hits on a solenoid thing. Forget about it if the computer isn't functioning, in limp mode or with no computer it doesn't work. It is there to step up the idle for an auto in gear or AC when it kicks on.

If the idle tubes on the carb are plugged which is common on older ones, then the curb idle screw might not be able to bring up the speed. If so post, that is a different issue as is the carb mix screws.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

snipped-for-privacy@columbus.rr.com wrote:

Reply to
Mike Romain
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I've got a 258 and what I think is the carter carb. In Chiltons (waste of money) it tells how to make adjustments to the "fast idle linkage" (that's about as close as it comes to explaining any adjustments to the idle). It doesn't say why you should make adjustments to this...just that you can make adjustments and how. I'm looking at an exploded view of the carb and there is a "fast idle retaining screw", a "fast idle speed adjusting screw", a "idle mixture screw" and a "curb idle speed adjusting screw". Now which one of these damn things should I adjust to make it stop stalling?!? The motor runs flawlessly (for not having an O2 sensor...that's another story...wires missing etc. etc.), the automatic choke kicks in/off when needed, never hesitates, just runs great except for the low idle. Thanks! Allen

83 CJ7
Reply to
<ABanks5

2bbl, round throat at the top, stock air cleaner, little white plastic pentagon-shaped vent connector on top of the float bowl at the front, that's the Carter.

On the driver's side near the base there's a multi-armed plate attached to the throttle shaft. On the firewall side of this plate are two spring-loaded screws. The one closest to the carb body rides on a plastic cam attached by a link arm to the choke plate, and through it to the automatic choke. That is to adjust the fast idle -- the choke pulls closed, the cam rotates and the screw prevents the engine from idling lower.

The screw closest to the fender doesn't ride on any cam, that's your curb idle screw. That's the one you're asking about.

Reply to
Lee Ayrton

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