QuestionHi Tazz,
A few weeks ago I asked you about a fuel odor on my 1966 Rambler Classic (inline 6-232 c.i.d.). You suggested replacing the gasket on the gas tank sending unit. I ordered the gasket and removed the tank. There were no signs of fuel leaking, but I replaced the gasket anyway. The rest of the tank is in fairly good shape. There was a rubber connector hose in the fuel line that could not be accessed without dropping the tank, so I replaced that as well. The fuel odor is still present, but I think I may have tracked it down. (It never seemed to be coming from the gas tank area, but I figured it wouldn't hurt to replace the gasket). Now, here is a review of what I have done so far: replaced all vapor tubes and rubber tubing present in the entire fuel system from filler neck to carburetor, installed rebuilt fuel pump (original Carter), rebuilt carburetor (original Carter WCD), and new gasket on the gas tank cap as well as checked the entire gas line for any signs of leaks. There are no visible leaks anywhere in the fuel system. However, the odor is strong in the cabin and I can smell it when driving. It seems to be coming from under the hood. When I look into the carburetor after shutting the engine off, I can see the butterfly valves at the base of the carb slowly becoming saturated with fuel. I can also hear some dripping but I can't be certain where it is coming from. Then there is a persistent odor around the front of the vehicle when parked. There is also then a strong fuel odor coming from the throat of the carburetor. I was thinking the needle and seat may not be closing completely, but it is a new (rebuilt) carb and that would seem unlikely. Also I don't think that would cause a fuel odor when driving. My thought is that the fuel pressure might be too high. This could explain excess fuel being dumped into the carb when driving and residual fuel being pushed past the needle and seat after shutoff due to the residual high pressure. (I installed a heat shield over the manifold to prevent excess engine heat from causing boiling of fuel in the gas line). So... my thought now is to put an adjustable regulator on the gas line. Do you think I'm on the right track here or do you have any other suggestions? It's the only logical course I can think of and I don't see anything else it could possibly be at this point. Any advice is appreciated.
Tony Cannata
AnswerIbelieve if it were dumping gas while driving, you would notice in the engine performance. I had a 23 Ford Roadster with three carbs that I put an adjustable regulator on and it solved all kinds of problems. My needle seat was being over powered by the fuel pump.
If I were you, when I heard the dripping, I would pull the air filter and look for myself. None of this explains the cabin smell while driving though. You may want to get drastic and remove your hood complete and go for a test drive.
Just a note, don't presume because a part is new or rebuilt that it does not leak or have its on set of problems.
Also, check your exhaust pipe for odor,It should smell like burned hydrocarbons, but not fresh gas.
