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CarburetorsCarb discussion and questions. Upgrading your Third Gen's carburetor, swapping TBI to carburetor, or TPI to carburetor? Need LG4 or H.O. info? Post it here.
having issues with my 1984 z28 that i bought it as a project. im trring to get her up and going but im having issues with the carb. it runs but idles very high. my research tells me that i need an adjusting fuel pressure regulator, but i also need to know the correct way to run the vacuum line for the brake booster to manifold as well as the vacuum line from the distributor to carb. lastly i have an old quadrajet on the motor but i bought a rebuilt carb in wondering if i can use the new one. all help is appreciated. i know im close dont want to give up
new carb, is it computer controlled ?
quadrajet.
having issues with my 1984 z28 that i bought it as a project. im trring to get her up and going but im having issues with the carb. it runs but idles very high. my research tells me that i need an adjusting fuel pressure regulator, but i also need to know the correct way to run the vacuum line for the brake booster to manifold as well as the vacuum line from the distributor to carb. lastly i have an old quadrajet on the motor but i bought a rebuilt carb in wondering if i can use the new one. all help is appreciated. i know im close dont want to give up new carb, is it computer controlled ?
Yes. Won't work with a vacuum/mechanical advance distributor.
Originally Posted by Z28kudos
quadrajet.
A little hard to tell from the photos, but I'm guessing you have a "hot air choke" on the carb that's installed on the engine. They can be converted to electric choke like is on the computer carb. But, without heat, the choke will never fully open, which will keep the high idle cam engaged, leading to a high idle when warmed up.
This gives you an idea of the vacuum routing for the vacuum advance. You wouldn't need the TVS, so just use port H.
So i pretty much need a new carburetor? And to run a vacuum hose from the distributor to the carb ?
Not sure why you'd need a new carb. Is there something about the one that's installed that is broken that doesn't show in your pictures.
I guess I didn't address the brake booster. There should be a port/fitting at the base on the back of the carb. That's where the brake booster attaches.
The vacuum port on the carb for the distributor is the one I indicated. Your picture shows it is capped now - pop the cap off and attach a vacuum hose to it to the distributor.
To "fix" the choke, you just need to get an electric choke thermostat and install it. Hopefully the 12v wire to operate it is still there.
I'd say run that rebuilt carb if you have all of the wiring for the ECM still there. But you'd also need a computer distributor, engine coolant temp sensor, and O2 sensor - I'm guessing that wiring is all gone (if the wiring harness is still there, and you can get all of the other stuff connected, then I would definitely recommend the computer carb).
Id like to use the rebuilt carb but im sure the ecm is disconnected and most the wiring is gone. Id like to find the least expensive way to get it on the road. Is it hard to change the choke thermostat on these old carburetors?
And honestly this is my first car with a carburetor. I just know that my car idles high and i have to pump the gas at cold start and it never drops down. Lastly i need help with my TV cable. I think im stuck in first. I know ive said lastly like 10 times. I appreciate you guys
Id like to use the rebuilt carb but im sure the ecm is disconnected and most the wiring is gone. Id like to find the least expensive way to get it on the road. Is it hard to change the choke thermostat on these old carburetors?
Not hard at all. It's that round black plastic thing held on by three screws on the passenger side of the carb.
But you'll need to find the 12 volt wire that attaches to it.
In the meantime, you could just loosen three screws, turn the black plastic until the choke butterfly opens, and run it that way. It will be harder to start cold, but it won't idle too high.
Lastly i need help with my TV cable. I think im stuck in first.
I've never heard of that. But setting the TV cable is pretty easy. Depress the "D" shaped tab on the cable housing by the bracket, pull the cable housing back while depressing the tab, release the tab, floor the accelerator. It'll self adjust when floored.
thats not a computer controlled distributor so even if you do get the computer carb connected up with the mixture control solenoid etc I cant imagine they will play nice with eachother or run right.
Can i pop the electric choke off the rebuilt computer quadrajet and swap it onto the hot air choke style quadrajet? And does the brake booster to carb hose need that plastic piece thats routed in between or can i just run a hose directly between the 2?
And do i need a PCV valve? Also i have a mechanical pump bolted to the block therefore i shouldnt need an adjusting fuel pressure regulator right ? Once again thanks for all the help
04-16-2017, 08:14 PM
