how to adjust you're choke and idle screws on a divorced choke q-jet carburetor
#forbesgarage #quaderajet #Rochestercarbrator #howto #1978 #78 #carburetor #rochesterquadrajet #divorcedchoke #chevy #350smallblock #howtoworkoncars #classicsquarebody #classiccars #tectips
Пікірлер: 53
You just solved my issue. Thanks.
@RattleTrapGarage
2 ай бұрын
Glad I was able to help 👍
Thanks for info. You explained exactly what problem I'm fighting. Now to bend rod and check vacuum module.
@RattleTrapGarage
4 ай бұрын
Good luck hopefully everything works out for you
@RattleTrapGarage
4 ай бұрын
You can also adjust it to open a little less I found that works better for smaller jets
Good video and a cool looking square body 👍
@RattleTrapGarage
Жыл бұрын
Thanks
THANK YOU SIR!
@RattleTrapGarage
6 ай бұрын
Np
Get the dealer tune up manuals. Like SD-100. Very specific procedures for setting everything. All the different carb numbers were adjusted differently too, even points were set at different specs. My 1972 factory 300 h.p. 350 is 4 turns on the fuel air screws, initially. According to that gm book, they ranged from 175 h.p to 375, for the 350. The later gm tune up books used exhaust sniffers to adjust, for NOX.
@RattleTrapGarage
28 күн бұрын
@davidpotter7484 this is really good information, I really appreciate it man best of luck to you, I over the past year experimenting with different jets and what not have noticed the choke likes different adjustments depending on jets and metering rods aswell as mixture screws, lots of things I wished I mentioned in this video
@davidpotter7484
27 күн бұрын
@RattleTrapGarage nothing is arbitrary on a factory set up, very specific settings. Extremely easy to just follow directions. Then, they start, run and drive just like new with the best mpg, if driven properly. I had major issues with vacuum lines for years, until i found places that still made them. Parts store vacuum lines will cause leaks as soon as they get hot.
Thanks
@RattleTrapGarage
7 ай бұрын
🫡
Bubba thank you for the content. I'm working on a divorce choke for first time and couldn't figure why it's locking up with a closed choke. After it warms up I turned off the truck and hit the gas and my choke closed tight and the truck wouldn't start again. Your saying bend the rod so it will release the choke with vacuum.
@RattleTrapGarage
4 ай бұрын
Yes
Hi great video! The vacuum port sticking out next to the mechanical choke what is it for? I'm not sure if I should cap mine off?
@RattleTrapGarage
Жыл бұрын
It's for the heat riser on the a factory air cleaner it's not that important
@Hendrix.
Жыл бұрын
@@RattleTrapGarage That's the Vacuum advance port on my 69 427. I'd cap it if not in use.
My 75 Chevy k10 has a carb just like this although its branded Edelbrock. Anyways it idles pretty high cold and the choke won't kick off until after the temp gauge is about halfway up. I can goose the gas to cut the choke off but as soon as i drive off again the choke is back on and the engine idles high. It takes forever for it to be warm enough not to do that. What would I adjust in this case? Sometimes I hit the gas and the choke won't open up. Like it sticking or something.
@RattleTrapGarage
3 ай бұрын
Yea there's that high idle screw between the choke pull off and carb itself you can lower the cold idle speed there, if you want to adjust the amount of time the choke is on you can Slightly bent that other rod going to the choke thermostat
I lose power going up hills. It used to drop down to 20mph. I adjusted the kickdown and now it will sit about 40. Does this issue have to do w the carb? There’s only hills around me in higher elevation so I’m thinking it could be that. It’s a k1500 that runs a little rich.
@RattleTrapGarage
9 ай бұрын
It could be a lot of things have you checked timing?
We just put a correct intake on and the child mounting surface is not there. We made a stainless plate to go from the two available bolts and mounted the choke via an aluminum sleeve in the middle of the plate. Seems to me that the heat is not going to transfer well to the underside of the choke body. Guess we are back to the drawing board unless you have a known solution??
Thanks very much for this video it's exactly what I've been searching for, quite awhile. I am missing the cover and the arm that closes the choke to start correctly on a 78 GMC 350. Any idea where I can buy the cover and the arm? The spring is still bolted to the intake manifold, but because I am missing the cover and that arm, the choke stays open and the engine is hard to start when cold. I've searched the internet quite a lot but no one sells it. Do you know where I can buy these parts?
@RattleTrapGarage
Жыл бұрын
I found mine on the internet search up; (Rochester quaderajet divorce choke) on Google and go to shopping and it will be there
@RattleTrapGarage
Жыл бұрын
You might be able to find one in a local junkyard too
@andymalanga
Жыл бұрын
TY!
@RattleTrapGarage
Жыл бұрын
Another thing make sure you have the right jets for your engine It will effect its cold start
can you clarify your idle mixture settings - you said they are turned OUT 3 full turns? does that mean you completely close them by turning them clockwise all the way, THEN three separate 360 degree turns counterclockwise from that fully closed position? thanks
@RattleTrapGarage
Жыл бұрын
I turn them all the way in then back them out 3 turns
@RattleTrapGarage
Жыл бұрын
And yes 3 full turns
@RattleTrapGarage
Жыл бұрын
Also 2 and 1/2 turns work too
Can you get a quadrajet carburetor turn right for a street cam engine
@RattleTrapGarage
5 ай бұрын
Since this video I have built a little built engine flat top pistons 487 heads with a larger cam and the quaderajet still runs Phenomenal the only thing I had to change was jetting and the power piston spring starts awesome gets around great cruises like you wouldn't believe, but yea you should be able to iv seen them on some pretty built engines they seem to work
So I’m having a problem where my car will start and warm up at a very high idle and it won’t go down give it a blip of gas and it will sit at the revved rpm for a while until it returns back to the high idle
@RattleTrapGarage
6 ай бұрын
I'd check the throttle cable and throttle linkage and shoot some oil at it also behind the choke pull off vacuum canister there is a screw to adjust high idle
So upon cold start butterfly has to be closed?
@RattleTrapGarage
3 ай бұрын
Engine cold 1 pump choke closed starts up automatically opens a smidge
What does "bog" mean?
@RattleTrapGarage
Жыл бұрын
It'll cut out repeatedly and have no power under acceleration
Hey buddy. My 83 cutlass starts up great when cold after pumping the gas 5-7 times. Drives smooth with zero issues but after shutting it of to go inside a store, it doesn’t want to start. I have to take the air cleaner off and hold the choke open with a rag while I turn the key and starts up. Why does the choke close so fast? Is my electric choke bad or something needs adjusting?
@RattleTrapGarage
Жыл бұрын
So it sounds like the choke might not be opening enough and when it sets it closes and won't start cause its flooding its self when the choke closes, i think it could be a bad electric choke element or the choke pull off could be bad, the vacuum canister on the right side of the carburetor. Try pulling the air cleaner and watch it when you start it and see if it pulls open when it starts
@RattleTrapGarage
Жыл бұрын
Also I have an 800 cfm with an electronic choke I might do a video on soon
@montrose5paulina
Жыл бұрын
Thank you and I will take a video of it. After watching your video, I only pumped it once like you say and it starts great. I don’t know where I got the idea to pump it so many times but thank you for the great video.
@RattleTrapGarage
Жыл бұрын
@@montrose5paulina you're very welcome
One of your lifters is gone
@RattleTrapGarage
Жыл бұрын
Loose rocker I fixed it
@rolexshine923
5 ай бұрын
@@RattleTrapGarage Why does this happen? I just picked up a 1980 corvette all original, it sounds exacly like a have a loose rocker too, but when it is warm and does idle and runs smooth, im just waiting on new cover seal to arrive to tackle this issue
@RattleTrapGarage
5 ай бұрын
@rolexshine923 mine actually ended up being a wiped cam lobe but it could be a lifter losing its prime were it will clatter on cold starts and pump up as oil pressure builds and the sound goes away
Replace that lifter
@RattleTrapGarage
Жыл бұрын
I plan too
@RattleTrapGarage
Жыл бұрын
Well the cam shaft ended up having 2 flat lobes so I pulled the engine apart and put a mild cam in it so now it sounds kinda cool