well i returned my holley carb like some of you suggested, and i took your advise and got an edelbrock 1406. i put it on, started the moter and the idle jumped up extremely high. ive messed with the idle screw that didnt help. i think its my fast idle or choke
(electric choke). when i get it running the only way that i can keep it running is to push on the choke plate closed. i adjusted the choke and when it is adjusted so that it will run it wont start back up. when i open it up it idles way fast again. i dont know if its normal, or makes a difference yet but when i turn the truck off a cloud of gas fumes come out the carb. please help.

 

have you done anything else like replaced the intake when it started doing this??? sounds like you may have a vacuum leak some where...........

 

i didnt change anything else. would that idle that way if my vacuum lines are crossed. there are 2 the same size and may have put them on wrong but i dont know if that will effect anything.

 

rework all the vacuum lines and looks for leaks mine started and idled fine when i got mine. but i think you will like this carb better than your last one. just keep the carb body clean, it tends to get corrosion on it after a while since the kind of metal used.

 

my neighbor tried to help and he turned one mixture screw a few times and didnt touch the other one. how do i fix what he did.
another question is there a high idle screw on this carb?

 

the factory settings i believe are both screws turned all the way in then turn them 1 turn out i think not sure.

 

well somewhat good news, it idles. i switched the vacuum lines and it idles the way i need it. once i figure out the mixture screws i think ill be in good water. it started up pretty good, i just need for it to get a little colder so i can see if my choke is where i want it at. but for now it runs. thanks for your advise.
quick question. without a meter how do i fine tune the mixture screws?

 

Turn the screws in till they seat. Not forcefully, you don't want to damage the seats. Back both screws out equal amounts (one to two complete turns should be enough to get you started). While engine is running at full operating temperature, start adjusting the screws 1/4 to 1/2 turn at a time until you get the smooth idle you are satisfied with. Adjust both screws equally, first one then the other. When you get your satisfied smooth idle, then adjust the idle screw to get the desired idling RPM. Then you can go back and adjust the mixture screws in the same manner above to fine tune the smoothness of the idle. Vacuum leaks and set timing will also affect the idle.

 

thanks ill try that and let you know how things went

 

Littlefoot,

It is well worth the few dollars to get a vacuum gauge in order to get your idle mixture screws set right. They can be had for less than $20.

To use it, connect it to direct manifold vacuum and with the engine warm slowing adjust the mixture screws one at a time until you have the highest vacuum reading. If the idle speed has moved up any significant amount turn the idle speed screw back to bring the speed down to where you want it. Then do the next mixture screw and reset the speed once again if need be. Then fine tune it by again checking that each mixture screw is set for the highest vacuum reading.

Once you have determined that you have the highest vacuum reading and the idle speed has been reset to correct speed turn each screw in (clockwise) just a slight amount to lean it just a bit. Turn them equally about 1/8 of a turn but not so much as to see a drop in vacuum. On the Edelbrock carb clockwise leans and counter clockwise richens. The best idle mixture is just slightly lean at idle.

Without the vacuum gauge you will have a hard time doing it by ear. The vacuum gauge will move more than your ear will hear. You can do it but it won’t be the best setting it will only be in the general area. The even better way is to use the vacuum gauge in conjunction with a large scale tach. But the vacuum gauge is the better of the two if you are only to use one.

Good luck,

Mark

 

Did you plug the threaded hole on that back of the carb? If not, you have a huge vacuum leak.

Jimmy

 

yes i plugged the hole in the back, i figured out that the two small vacuum lines needed to be switched around. everything is all good now. edelbrock told me that the mixture screws come out of the factory at 2 and 1/2 turns so thats where i left them untill i can get a vacuum meter. so far i am happy with this one. alot more power. thanks all!

 

Glad to hear it.