2003 crown Vic leaking fuel. Please Help!! Emergency

Hi, I can across this site trying to find out why my car keeps leaking gas. Here's my deal.

It started with a gas smell, then turned into a decent leak up under the gas tank. I took off the two nuts that hold the canister vent valve solenoid and the flat rectangular box up to the gas tank. Fuel was pouring out of the seam of the vent valve solenoid. So I replaced it with an auto zone part. Same issue. Returned the auto zone part and went to Napa and picked up a premium part there, hose clamps, and a new length of fuel vapor hose. I installed all the new pieces and problem was fixed. Drove it, stopped, parked on inclines and declines all day yesterday, not a single leak or smell. Now however, after throwing some gas in her, it is leaking from this exact same spot, and it didn't happen until I put the gas in.

I did just put gas in it and it took it to just above 3/4. Looking back, after I put the part from auto zone in, I filled her up that time and it began leaking as well. This leads me to believe it has something to do with a clogged vent line somewhere, but I have no friggen clue where to start or if that is even a possibility. My other thought was it was leaking from up top by the fuel pump o ring or further up the vapor hoses, but it is only wet with gas down there at the solenoid. I have a 6 yr old son I drive in this car, and it is my only vehicle and really need some help fixing this. I've also got to get through emissions and I know they ain't gonna pass me when I'm dumping fuel on their bay floor.

Speaking of emissions, my obd II is not connecting to ANY code reader. I haven't checked the fuses yet, headed out to do that right now since I'm stumped on the fuel leak. My cigarette lighter and everything else on the dash works, does the obd run on its own fuse? The MIL doesn't light up on key on but everything else does. Plus, my battery light is on constantly while driving, but I have no problems with starting her ever.

This is an old police interceptor. It has all the wires and hookups for their computers and lights. Its got the dual spotlights, back doors won't open from the inside still, and it will do 140 before you know what's going on. :-) The guy I got it from just replaced the alternator and put a new battery in it. Its got 125k on the odo too. Just a little background info in case it helps. Please if you have any suggestions put them here. I have to get this fixed asap as my tag runs out in three days.

Liquid gas at the canister vent solenoid means fuel is getting into a line that should only ever carry vapor, and the fact that it only happens after a fill-up points to the tank's own valving, not the solenoid you replaced.

When you fill up, the vapor pushed out of the tank is routed to the charcoal canister, and a fill limit valve in the top of the tank is supposed to close when the fuel level reaches it so that only vapor, never liquid, goes down that line. If that valve sticks or the tank is topped off past the first click of the pump nozzle, liquid gets pushed into the vapor line and the canister, and it comes out at the lowest leaky joint, which on your car is the vent solenoid.

So: stop at the first click when you fill. If it still leaks after a normal fill, the valve on the tank (often part of the tank or the sender assembly, depending on the part) is the next suspect, and a fuel soaked charcoal canister should be replaced too, since it will keep pushing raw fuel. Until it is fixed, a car that drips gasoline is not one to keep running, especially with your son riding along.

On the other question: yes, the diagnostic connector has its own fuse in the interior fuse panel, separate from the lighter, so check it against the legend on your fuse panel cover. Fix the check engine bulb not lighting with the key on before the test too: ex-police cars often have that bulb pulled, and the emissions test fails on a dead bulb or a dead connector by itself.

Dana