Jump to content

new carb

Guest 1onesy

Recommended Posts

I have an 85 riviera with the 4 barrel that has all kinds of idling problems and whatnot.I don't want to deal with all the components and trying to figure out which ones are bad.So, can I replace my carb with an aftermarket one like edelbrock so i can disconnnect the computer plug and all that hosing and emission junk that does not function correctly anymore?

Link to comment
Share on other sites

  • 2 weeks later...

If you live in an area which requires emissions testing and a visual inspection, you will not be able to remove the emission gear. Although a bit daunting at first, the GM CCC (Computer Command Control) system of that era is not really complicated. Your computer controlled Rochester 4bbl is a fine carb once it's rebuilt (if necessary) and properly adjusted.

Owning a car of this era requires a desire to 'get into it' or a trusted mechanic who is willing to troubleshoot for you. Jayson is knowledgeable about CCC and the factory service manual is your best friend (or your mechanic's!).

I am the original owner of an '84 Toronado with the same engine & CCC system (189,000 miles). It certainly needs attention from time to time, but it's all stock & runs very well.


Link to comment
Share on other sites

Guest TwoDoorBuickMan

There is an item that can make these cars idle rough, use extra gasoline and at times cause black smoke from the exhaust when it fails. I have found it to have failed on about 50% of the cars I have owned with the 307 Oldsmobile engine. It is a Canister Purge Valve. If you are looking at the carburetor from the front of the car, the valve will be below the carburetor to the left. It is a black plastic control valve about 1 1/2 in. across with 4 vacuum hoses coming from it. 3 of the hoses go to the carburetor and one goes to the emission cannister through a temperature control valve. It can fail in several ways and can draw raw gasoline vapors directly from the vent chamber and send them into the intake manifold through one of the vacuum hoses. The valve can be checked with a vacuum pump.

There are some other ways to tell if it has failed. If the car is running, the hose going to the vent chamber may be cold or even iced up. You can remove this hose from the carburetor and plug it up to see if the car runs better. Another way to tell if it has failed is to remove the hose at the canister that goes to the valve. The car should idle and run better if the valve is the problem.

Autozone has these valves for $12.99. I always carry one in my tool box.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...