Your Pontiac Parisienne is a classic American car that was designed with a durable carburetor. Through the years of constant use, the carburetor of your car will eventually wear down, especially considering the Parisienne model belongs to the older generation of Pontiac cars. Here's a list of some common signs which could tell a malfunctioning carburetor. If any of these are prevalent in your car, then better be ready to look under the hood.
If you have been cranking the ignition switch, but the engine still fails to start even after a few attempts, then it may lead to a faulty carburetor. A problem you might encounter here is that there can be a number of possible causes. The best way to solve this problem is by checking the condition of the carburetor first. The carburetor's choke adjustment and linkage have to be inspected because there should be no object that restricts or bend the parts.
Another sign of a carburetor in bad condition is poor gas mileage. There are some other parts that can cause your carburetor to work inefficiently, and one of these is the exhaust pipe. This part has to be checked if it has been plugged. It should also be checked if it has been crimped or kinked. In any of these conditions happened to the exhaust pipe, then it has to be cleaned because dirt or other foreign matter have accumulated already.
A poor carburetor can cause gas to pour out when the engine is turned off. This may be caused by a defective vent valve in the carburetor, or the valve is stuck or blocked. If any of these signs are present, then an immediate replacement is needed. A leaking carburetor can also be caused by a gas line that is located too close to a heat source like the radiator hose or exhaust manifold. The gas line has to be positioned and secured away from these parts.
Observe the condition of the engine when performing cold and warm starting. These could show signs of a carburetor that's wearing down. The engine should always start smoothly whether it's a cold or warm start. However, if it fails to start completely, dies after a few second, or produces smoke, then you will need to inspect the carburetor immediately.