My rear barrels are not opening up and it is not the thermostat. When the front barrels cover is fully open. The rear barrels will not open. They are not stuck and everything appears to be in working condition. But there is no linkage chain on the left side of the carborator as you are looking at it. The linkage is there on the right side and the front barrels open just fine. So does it need a linkage on the left side to open the rear barrels?
2006-08-12 17:35:48 · 9 answers · asked by d_rea04 1 in Cars & Transportation ➔ Car Makes ➔ Chevrolet
It is vacuum operated. The back barrels will not open when you are under the hood revving the engine. The engine has to be under load for the engine to produce the vacuum for the barrels to open.
If you want to make sure they are opening while driving. find the vacuum housing that is on the side of the carb that has the rod running down to the linkage to the rear barrels. tie something like a twist tie that comes on bread and tie it around the rod where it clings pretty good and slide it right up to the vacuum diapram housing. Go drive the car and open it up. when you get back... look to see where the twist tie is. If it is down on the rod, your carb is working right. if it is where you tied it, then your vacuum diapram may be torn.
2006-08-12 18:04:22 · answer #1 · answered by crazytrain_23_78 4 · 1⤊ 1⤋
You have a quadrajet 4 bbl, the rear barrels operate on vacuum.
The vacuum is not manifold vacuum however, the vacuum is created by air flow through the carburetor venturies.
As the air increases through the front barrels it causes a vacuum to operate a diaphragm that opens the rear barrels.
No it does not need a linkage to the throttle or to the front barrels.
The rear barrels open only when the air demand creates enough vacuum to overcome the return spring on the rear butterflies.
Holly and Edelbrock make some nice 4 bbl's with mechanical linkages if you want foot control of the carb.
My $0.02
Yours: Grumpy
Yours: Grumpy.....did it echo in here?
2006-08-12 18:06:50 · answer #2 · answered by Grumpy 6 · 1⤊ 0⤋
stay away from the adapter plate, you'll gaiin noe take advantage of the addition of a 4 barrel in case you nonetheless have a 2 barrel-sized hollow contained in the properly of the intake. bypass with an Edelbrock performer rpm sequence manifold. You'r gas mileage heavily isn't adversely affected except you position in something huge. keep on with a 650 or a lot less cfm 2-level. there'll be some linkage adapting you'll want to do for both the vehicle choke and the throttle.
2016-11-24 22:31:49 · answer #3 · answered by yancy 4 · 0⤊ 0⤋
You are talking about a quadrajet I assume. The vacuum of the engine pulls the two back barrels open when called upon, a spring closes them when the vacuum decreases. There is a little rod on the side of the barrel shaft that holds them closed until the engine is up to running temperature. I would recommend that you take it to a professional
2006-08-12 17:48:11 · answer #4 · answered by Anonymous · 0⤊ 0⤋
if its stock they are vacuum engaged secondary , called progressive secondaries, there is a diaphragm called a secondary diaphragm and it runs off vacuum if its a quadrajett GM will have a # starts with 170....... on the driver side on the back venture"if so the diaphragm is on the other side and be sure its hooked up if been altered need to see it not from a computer key board
2006-08-12 23:20:03 · answer #5 · answered by Ruthie W 2 · 0⤊ 0⤋
if choke is not fully open ,a lever will prevent rear barrels from opening also.
2006-08-13 06:11:04 · answer #6 · answered by deltech 4 · 0⤊ 0⤋
no chain involved --lack of flow or something is stuck
2006-08-12 22:32:46 · answer #7 · answered by michael_stewart32 4 · 1⤊ 0⤋
i think its something to do with engine air flow.
2006-08-12 17:38:14 · answer #8 · answered by ricky 4 · 2⤊ 0⤋
YES!!!!!!!
2006-08-12 17:39:01 · answer #9 · answered by neverchild 2 · 0⤊ 1⤋