When I purchased my 69 Coupe it had a leaking fuel pump. 
It took me a while to realize this. On day instead of just warming the car up in the garage and leaving, I warmed it up in the garage, pulled out and then came back into the garage. There was a pool on the floor which turned out to be gas. This explained the heavy gas odor and really bad mileage. 
When I did the first oil change after purchasing the car, the oil was especially thin and nasty. I figured it was simple from neglect. Now I think it may have had fuel in the oil. 
This seems like a good thing to check if you ever have a leaking fuel pump.  
----- Original Message -----
From: sosmi@xxxxxxxxxxx
To: mailing-list@xxxxxxxxxxxxxxxx
Subject: Re: IML: Fuel Leak
Date: Wed, 06 Jun 2007 13:39:51 +0000
That vent hole, has a two fold job. It is a pressure vent to keep one side of the pump diaphragm at atmospheric pressure, the second is a by-pass for fuel when there is a pump failure, which dumps the fuel on the ground rather than going in the crank-case.I would check the oil, to make sure there was no fuel dilution. By plugging or restricting the vent, you may have caused fuel to enter the crank-case.Dave.
 
-------------- Original message -------------- 
From: "tdcox" <tdcox@xxxxxxxxxxxxx> 
> Thanks, Eric 
> 
> That is my guess, too. Since the right side of the car was excessively dirty 
> with an oily slick, I am assuming that gas mixed with rain to cause the 
> problem. Since the fuel pump is the most likely candidate on that side of 
> the engine (other than the fuel filter), that is where I am going to start. 
> 
> -----Original Message----- 
> From: mailing-list-owner@xxxxxxxxxxxxxxxx 
> [mailto:mailing-list-owner@xxxxxxxxxxxxxxxx] On Behalf Of Eric 
> Sent: Tuesday, June 05, 2007 11:00 PM 
> To: mailing-list@xxxxxxxxxxxxxxxx 
> Subject: IML: Fuel Leak 
> 
> Tom, 
> Thank you for sharing your photos of your beautiful '56 coupe. 
> http://www.imperialclub.com/Yr/1956/56Cox/in dex.ht m 
> It's no wonder 20 people stopped for that beauty! 
> 
> About your fuel situation. I had a mysterious raw fuel smell with my '64 
> Crown Coupe. I never saw a leak on the ground but I did notice the rubber 
> hose to the fuel pump was delaminating down to it's threads. I thought this 
> was the source of the fuel odor, that it may be seeping from this hose. I 
> put it on my long to-do list. 
> 
> To make a short story more exciting, I'll explain how I learned the real 
> source of the odor. I was being tailgated on a stretch of open hiway a 
> couple of weeks ago. I thought I'd show the tailgater something so I floored 
> 
> the throttle. After losing him in a cloud of unburned hydrocarbon droplets, 
> I realized he was lost in a whole lot more smoke than there should be. Then 
> I heard a noise, felt a loss of power steering assist, and decided to pull 
> my old smokey over to see what broke. 
> 
> A few days prior to this, I noted one of the twin A/C - alternator belts had 
> 
> a twist in it around the bottom of the crank pulley. I had planned a 
> replacement of these belts soon so I left it as it was. This belt then broke 
> 
> when I floored the throttle, throwing it's twin off, as well as throwing the 
> 
> power steering belt off, answering my loss of power steering. The broken 
> belt snapped apart the transmission coolant line compression fit connector 
> causing transmission fluid to spray all over the compartment, explaining the 
> 
> large cloud of smoke. 
> 
> I made short work of straightning the bent transmission line, reattaching 
> the compression fit connector, refilling my transmission with fluid, and 
> putting back the power steering and the remaining A/C - alt belt. When I 
> started the car, I let it idle and watched for l eaks a t the transmission 
> line fitting. It didn't leak but I did notice a substantial leak at the fuel 
> 
> pump. This fuel pump leak was in a spot unrelated to my snapped drive belt 
> trouble and I could see that it was spewing gas onto the above mentioned 
> fuel hose that had deteriorated. 
> 
> On one side of the fuel pump, there is a round, drilled hole right above the 
> 
> diaphram. Fuel was being pumped out from this hole. As an emergency roadside 
> 
> fix, I found a disposed of cigarette butt and compressed it into the hole. 
> That butt helped, but it did let a bit of gas to be spit out, and provided a 
> 
> wheezing noise. We got a kick out of my bronchitis afflicted filtered fuel 
> pump leak. 
> 
> I've not yet opened up the leaking fuel pump, but I suspect the diaphram may 
> 
> have ruptured long ago. I had a used fuel pump that I later replaced it w ith > 
> and it is without this hole. Maybe this hole is an early warning mechanism 
> to tell the owner that the pump is about to go? I have a new pump for a 
> Slant 6 that does have a similar vent or bleed hole. 
> 
> Short story of it is, you may want to check your fuel pump for leaks with 
> the engine idling. 
> 
> Hope my long mysterious leak tale helps your situation. 
> 
> Eric 
> 1964 Crown Coupe 
> ________________________________________________ 
> From: "tdcox" 
> Subject: IML: 2,000 mile trip 
> My wife and I have just returned from a nearly 2,000 mile trip in our 56 
> Southampton coupe. 
> ...The only odd thing that we noticed on our return trip was that our gas 
> mileage dropped in half, to about 7 mpg. I was pretty sure the timing = 
> was off but didn=92t expect such a decrease. When we arrived home, I washed 
> the 
&g t; car and found that the entire passenger side of the car had a thick oily 
> substance all over it. Also, we smelled gas fumes on the last half of = 
> the trip. Wonder if this could be a leaky fuel pump; the oil level was fine, 
> 
> so 
> I assume it is fuel related. 
> Thanks to the Webmonsters for adding pictures of our car to the 
> 56 Imperials 
> 
> 
> 
> 
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