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Spitfire Persistant gasoline smell

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N

number6

Jedi Trainee
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I've owned Sabrina for about 3 years now and at the end of last season started noticing a strong gas smell after I start the car. Prior to me owning the car it was converted to a Weber
setup, which I have never liked. I have done all the checks I can think of. Replaced all tubing in the fuel system, rebuilt the Weber, etc. Still have the smell. Since Webers are fuel pressure sensitive, I first thought the fuel pump was overpowering the Carb. Fuel pressure is around 3 PSI on Fuel pressure gauge. Just to be sure I didn't miss anything I had her checked by my local British car mechanic. He checked fuel tank for leaking, emission system, and nothing obvious to him either, only thing he mentioned was the fuel filler cap gasket
looked sketchy. I have a new SU HD8 carb from one of my rovers and am considering installing that, one to perhaps solve the problem and two give me a carb I know how to tune.
Thoughts and suggestions at this point would be helpful.
Tom S.
 
I know how much you dislike the Webers, but I wouldn't be too quick to blame the smell on them. Gas leaks are hard to see because the stuff evaporates so quickly. I've had some success following my nose to the gas leak. Use a clean wiper or paper towel around suspect areas, which will pick up the smell from the leak.
Of course, if you are going to go to the SUs anyway, you just might fix the problem.
Tom
 
Tom - is the gas smell *only* just after you start the engine? Or do you mean you smell gas all the time once the engine is running?

Tom M.
 
Over the years I have had several issues with a gas smell. In most cases I am able to follow the fuel flow from the tank to the carbs. Using my clean bare hand I rub my hand along the fuel lines, fuel pump and around the carbs. By frequently smelling my bare hand I have been able to isolate a place where fuel is weeping out. Once you have gas on your fingers you will need to wash with soap and water to continue from that point.
Charley
 
The smell is just after I start the engine, occasionally I can smell it when I am driving with the top down, it's that severe. I even checked the fuel pump to make sure it's not dumping
into the oil pan. And yet sometimes it goes away for 20 minutes or so. I can't see anything obvious when the engine is running and I am staring at it. No gas leaks on the driveway, so it's not
dumping on the driveway. There is not much of the original emissions system left, although there are two canisters still in the compartment, but they are isolated. I will go out
tommorow and do the paper towel and smell test.
 
I've used aerosal foot powder sprayed in the area. Seeps seem to show up in the powder and it wipes away easily.

BTY, is Horsch part of the Auto Union?
 
If both canisters are isolate where does the vent hose from the gas tank end up?
 
Horch was part of auto union in the early 30's. Direct ancestor of Audi. I have an 830 V8.
The question about the vent hose is a good one. The mechanic who worked on it last said he blocked it off.
I am going to check that today.
 
That hose shouldn't be blocked off. If it is no air can get into the tank as gas is taken out. You may find that the car quits suddenly from lack of fuel.
 
I was wrong about that, hose is open. I did take the car for a lengthy drive and once home, rechecked everything I could see. All hose connections, fuel pump, etc. With the car running I pulled the air cleaner and with a paper towel tried to find any leaks. Nothing. I did notice one thing I didn't see before. The hose going from the Weber to Valve cover was in bad condition. Hose is old style fabric type. Replaced it and will try tomorrow. If that doesn't cure it I am going to ask Tom Mull to help me look, two sets of eyes may help. I am still of the opinion its the Weber.
 
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