Hi I am new to the forum. I recently purchased a '73 Buick Estate. Car runs great but smells bad of raw gas. I cannot see any gas leaking underneath. The previous owner told me it needs a carburetor rebuild. Could this be the cause of the gas smell? Or is there somewhere else I should be looking? The smell is really intense when driving at high speed with all the windows rolled down. Any help is greatly appreciated! Thanks!
Welcome to the forum! I speak for all when I say we’d love some pictures! Could be a leak at the tank vent, piping gas fumes into the cabin. But I’m guessing it’s probably in front of you, where the leak is.
OK thanks! Also the garage smells like gas after a drive....even into the next day if that helps with the diagnosis.
Check the car cold. Look for any fuel around the fuel lines, hoses, connections and all around the carburetor and around the fuel pump. If you do not see any wetness or indications of fuel having leaked, start the car and run it only for about a minute, long enough to look for leaks, but not long enough to get it warm. The shut it off and continue to look for leaks for a few minutes. It may be obvious from fuel pressure. Post back what you find out.
Pull the air cleaner and start the car. Make sure the fuel line to the carb is not leaking on the intake manifold.
My money is on either the supply or return hose connection at the fuel tank sender. The fumes are coming in from the "station wagon effect". ws
It could also be the fuel cap. I had that on my first car, a 72 Skylark. Smelled gas while driving it.
Check the fuel fill pipe into the fuel tank. There's a rubber gasket to seal them which could have dried out or cracked. I've experienced this on two cars over the years. Another slim possibility is a leak in the fuel fill pipe itself. Yup, dealt with that too!
Not sure about a '73, but '72 had an evaporation system manifold located behind the rear seat back. There are four or five hoses that are connected to it, all of which carry gasoline vapor. If any of these hoses are cracked or broken, you will get gasoline fumes inside the car.
Don’t forget the short rubber hose connections halfway down the frame. No one ever changed them I bet. They crack and get brittle . In fact change every fuel hose on the car.
OK, thanks for all the recommendations! There was a small rust hole in the gas tank that leaked gas onto the tailpipe. I changed the gas tank and also installed a rebuilt carb. The gas smell has been reduced but the car still stinks when running. Seems to be coming from the tailpipe. Eyes burn if you get too close. No smoke, just a strong smell. What else can I try? I was told the rebuilt carb was adjusted and just needed to be bolted on, so that is what I did. Any other recommendations would be greatly appreciated. Thanks
That can be several things. 1. Choke stuck. 2. Retarded timing resulting in incomplete burn. 3. Vacuum leak, causing high fuel flow in idle circuit to try and compensate and that results in incomplete burn. 4. Idle circuit to rich. If the car starts and will idle under 1000 RPM when warm, try the following. Check timing with vacuum advance hose disconnected and hose plugged to the manifold, with a vacuum gage connected and see what your vacuum reading is at idle. Timing should be about 6 deg BTDC, and idle should be set at about 800 in park and 650 in drive with parking brake set. Note the vacuum at those settings. Then using the vacuum gauge, adjust the idle mixture screws on the front bottom of the carb to obtain the highest vacuum reading. You may need to adjust the throttle idle set screw (inkage) to keep the RPM correct during this process. Keep an eye on the engine temp, as some cars tend to overheat when idle long time with the hood open.
