How do i drain my 98 mercury mountaineer gas tank? I accidentally put diesel fuel in n now it wont start!

no drain plug and wont start or if starts will barely run or stall need to drop tank to get all diesel out also will need to flush lines

This site may have all your answers:
http://www.autobytel.com/car-ownership/maintenance-repair/accidentally-putting-diesel-in-a-gas-car-104029/

Basically do NOT drive the car and have the gas tank drained or talk to a mechanic.

Accidentally putting diesel in a gas car If you know that you have accidentally put the wrong fuel in the car, then don't compound the mistake by driving the vehicle while trying to think about what to do. Instead, call your mechanic immediately. At this point, the damage isn't permanent. If you drive and continue to drive, at one point the vehicle will stop and you will still have to have it towed.

There are two things you can do to try to fix the damage:
1. Try to clean up the damage yourself - have the vehicle towed home if it's not there already, and get as much of the diesel fuel out. How? By siphon if you can or any other method that you have available. Once you have as much of the diesel out as you can, fill the tank with the correct unleaded fuel that you normally use. Try to start the vehicle. It could take several attempts but it will start and it will smoke - a lot. It will continue to smoke until the last dregs of the diesel make its way through the system. It might run a little rough until everything is cleaned out. How it runs will depend on the proportion of diesel fuel relative to gas left in the tank.

2. Alternatively, have your vehicle towed to where your mechanic is and have the fuel tank drained of all the diesel fuel by a profession. They are also likely to flush out the whole fuel system. If the diesel stays in there for too long (and who knows how long is too long for your particular vehicle), it could ruin the fuel pump, lines and injectors. It is also possible that the diesel could have gummed up the spark plugs and filters. If this is the case, they will probably need to be replaced. Getting a professional to do the job will cost you anywhere from $100 to $500 and possibly a little higher depending on the extent of the damage.

To solve the problem, drain all of the diesel fuel out of the gas tank and refill it with gasoline. (If possible open the fuel line near the injectors, place a flexible tube of some kind over the fuel line and drain enough fuel to allow all of the diesel fuel to be removed. Get as much of the concentrated diesel fuel out of the line as you possibly can before attempting to start the engine.) Then you would have to keep cranking the engine for a while to get the diesel out of the fuel lines and the injectors. Eventually the engine would start and run fine.

Use a bottle of yellow HEET dry gas to remove any moisture problem in the fuel.

Use starting fluid to aid starting.

Have you checked the coal pack? or the plugs?

There is a vent hose that comes from the tank back to the filler neck, it could also be the filler neck hose. Might be kinked or seperated.

Check the fuel pressure with a gauge. The pump may be going bad

if it hasnt been ran for 2 years, i would drain the gas. put some 90 octane gas into it with some fuel injector cleaner if it still dont start, check the fuel pressure by disconnecting the quick connector from the fuel rail should have 35-40 lbs of pressure if it is way low or none fuel pump is bad

Try to take a look at the fuel fill hose that goes to the tank. Does it look resticked at all?

You must drain all the diesel fuel out of the tank and purge the fuel lines as well or it will not start.