Ive have an ’87 420 with 148K miles and occasionally I get a whiff of fuel in the cabin. I suspect it’s the EHA valve that needs to be replaced but haven’t done it yet. Today I was driving to the coast north of San Francisco. It’s a long, curvy, downhill road to the ocean -about 5 miles. I put the car in 2nd gear to save the brakes and let the engine do the braking for me. A short while into the downhill coast, the fuel odor became really strong. I almost got a head ache from it. Even with all the windows open I could still smell the gas. I even stopped the car and looked under the hood to see if a fuel line was leaking it was so strong, but there was no leak. I had just topped off the tank before I began the trip and thought maybe there is a crack in the neck of the fuel tank, and maybe I was dripping fuel from the rear but there was no sign of a fuel leak there. Also I dismissed the crack fuel tank neck theory because whenever I remove the fuel tank cap to fill up, there is always a good suction seal that I hear. But when I opened up the trunk it also smelled of fuel. Could this coasting in 2nd gear downhill make a EHA valve crack leak more pronounced? Or any other suggestions on where I could be looking for this fuel odor leak?
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