Quick carburetor question.

[digimurda]

hi,
i have a 85' 442
i've noticed for the past 2weeks that upon start up the car no longer idles high on the first cold start like it use to.
it also take alot more taping on the gas for it to turn on and when it does its on a low idle on 1000rpm.
is there anyway to get it back to normal? is it a carburetor issue?

 

[Pontiac455]

Either the themostatic spring is getting bad and not closing the choke or the fast idle cam is siezing up. Take off the breather when the engine is cold give the throttle a roll and watch the choke.

 

[digimurda]

ok, and what should i look for once i do that?

 

[Pontiac455]

If the choke doesn't spring back to close position check the theromastic spring, if it does than the fast idle cam must be stuck spray it up with some penatraiting fluid. The fast idle cam is on the right side of the carb in behind the theromsatic apring boss.

 

[digimurda]

ok, thanks. ima get to it after work, sorry for asking soo much but i dont know much about carbs.
ill try and hunt down a diagram or picts on here just to know exacly whats what, lol

 

[digimurda]

Hey, so I did as you said and the choke didn't close.
Should I replace the thermo spring?
Any particular process into removing and installing one?
I unscrewed the 3 screws and heard something so I took off completely.
Is there any particular way or thing I should do before putting it on?

 

[Bonnewagon]

Put the spring cover back on and turn counterclockwise while holding the throttle open with a screwdriver. If it has a square hole in the spring, that goes onto the choke rod inside the cover, otherwise the arm will eventually catch the rod. As you turn it, it will contact the choke rod and close it. When it closes tight, stop, and tighten the 3 screws. Now start car and see what the fast idle rpm is, should be between 1500 and 2000 rpm. If not, adjust with the screw at the bottom of the choke mechanism. You must work fast, as the electric choke heats up quickly and you need a cold choke to adjust properly.

 

[digimurda]

Put the spring cover back on and turn counterclockwise while holding the throttle open with a screwdriver. If it has a square hole in the spring, that goes onto the choke rod inside the cover, otherwise the arm will eventually catch the rod. As you turn it, it will contact the choke rod and close it. When it closes tight, stop, and tighten the 3 screws. Now start car and see what the fast idle rpm is, should be between 1500 and 2000 rpm. If not, adjust with the screw at the bottom of the choke mechanism. You must work fast, as the electric choke heats up quickly and you need a cold choke to adjust properly.

Hi, why should I hold it open with a screw driver if I'm going to close it tight?

 

[autowizard]

What carb are you working on? Holley? Eddy? Quadrajet?

 

[Bonnewagon]

The throttle will put pressure on the linkage. When you first go to start the car in the morning, you tap the gas pedal to set the choke. What happens is, is that when the throttle is lifted, the choke can then close. As it cooled, the spring wound against the choke rod, but the throttle held it open. When you tap the pedal, the choke snaps shut. After it starts, the vacuum operated choke pull-off opens it a bit, then as the choke heats up, it opens all the way.