Carb Question I think?

1975SPORT · Oct 2, 2006

New to the forum, not new to the site. You guys do a great job helping eachother out. Recently I bought an Edelbrock 600 carb, its installed and working. However, since the install my bronc runs high in the RPM range and takes forever to kick down. Then once you put in in drive the RPM's jump to about 2500 and stay there until the rig warms up for about 20 minutes. Also when your driving you can shift into neutral or park give it some gas and it'll kick down to idle, but once you put it in drive and give it some gas it jumps back up to 2500 rpm.
This usually happens a few times and then it runs just fine. Some of my buddies said it was the electric choke, and that it needs to be adjusted, and then a mechanic in town said that it could be the timing as well.

Anyone have any idea to make the bronc run better.
Any help is greatly appreciated.

Skiddy · Oct 3, 2006

Sounds like the choke adjustment to me, also could be sticking a little also.

eb66to77 · Oct 3, 2006

I have the same carb on mine and also have a C4. If it is only doing the high idle thing when it is cold and then only intermitently it is probably the high idle adjustment. It is a screw that adjusts when, how long, and how much the high idle is activated. It is on the drivers side of the carb. Adjust this screw out if you only want the high idle to stay on right at first. That is the way I have it. I wanted it this way since I give the truck plenty of time to warm up and don't want the issues with the high idle after I start driving like you have now.
To adjsut your choke unscrew the three torx screws on the passenger side. While the engine is cold push the throttle lever all the way towards the firewall and hold it with your right hand. With your left turn the black dial of the choke until the valve on the carb opens barely, about 1/8". Then tighten the choke back down.

Edelbrock has all the adjustment instructions and tuning stuff on their site in pdf format.

1975SPORT · Oct 3, 2006

Its not the idle, I have adusted that, but thanks for the info on the choke, appreciate it.

RangerRob · Oct 4, 2006

One other thing on those chokes is to make sure that you have a good source of switched 12 volt power to them so they warm up like they are supposed to. I found that the power coming off of the alternator (original choke wire) wasn't a full 12 volts and it would cause the choke to operate like you are describing. Moved over to another 12 volt source and all is good.

You do need to have the choke adjusted properly though and the previous posts describe how to do that. As mentioned by eb66to77, get the instructions off of the Edelbrock site and spend some time reading.

Good Luck!!!

eb66to77 · Oct 4, 2006

1975SPORT said:
Its not the idle, I have adusted that, but thanks for the info on the choke, appreciate it.

The high idle screw and the idle screw aren't the same thing.

1975SPORT · Oct 4, 2006

Cool, thanks guys i really appreciate the advice...sounds like those are probly the problems. I will try them right now and let you know how it goes. And thanks eb6677 I didnt know the difference between the two, I usually just figure stuff out, things dont intimidate me, but its great to have advice so the process goes faster...greatly appreciated.

1975SPORT · Oct 4, 2006

One other thing also RangerRob said that i need a good 12 volt source. I know its connected to the alternator like he was saying. Where would a good twelve volt source come from. May be a stupid question, but carbs are not my thing

...thanks again

eb66to77 · Oct 5, 2006

Trial and error isn't always a bad way of doing things especially when it doesn't cost anything. It also provides a systematic method of problem solving for me. I clean 12 volt source for the choke would be a wire that is hot while running. Use a test light to find it. I would disconnect the power supply for the choke and insulate the end, then make a new wire to hook to it the new power source and choke. It is a regular spade end.

1975SPORT · Oct 5, 2006

Thanks for all the suggestions guys, I really appreciate it. Its fixed and running better than it ever has. It was the idle speed screw mostly and then I also had to adjust the choke. But the rig is very happy as am I. Thanks again guys.

eb66to77 · Oct 5, 2006

Sweet man, Now go tear it up

Carb Question I think?

1975SPORT

Sr. Member

Skiddy

Bronco Guru

eb66to77

Bronc'Ownly

1975SPORT

Sr. Member

RangerRob

Full Member

eb66to77

Bronc'Ownly

1975SPORT

Sr. Member

1975SPORT

Sr. Member

eb66to77

Bronc'Ownly

1975SPORT

Sr. Member

eb66to77

Bronc'Ownly

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