I have a 1979 Dodge Magnum XE that has been sitting for 16 years. Is there a drain plug on the fuel tank? Also, any advice on getting the old fuel out of the lines and cleaning out the tank? Thanks.

 

I'm not sure about the magnums (are they a throttle body?) but I don't THINK* there's a drain plug (there usually isn't) but someone correct me if I'm wrong-

Basically, how I do it is;
Unhook fuel lines, filler neck, sending unit and straps and drop the tank.

Using the filler neck, I tilt the tank to dump the old fuel out (using the filler neck to aim it), and then I gather up a good length of chain and cleaner (of your choice) put them in the tank and agitate the tank (shake the crap out of it) allowing the length of chain to bang around inside the tank and break up all the junk.
Repeat until she's shines like a diamond and looks new again.
(You can then treat the tank inside and prep and paint the outside before install don't forget to replace the fuel sending unit.)
Replace fuel filters, rebuild carbs etc.

I unhook the fuel lines (front and rear) and use my air compressor to blow out the lines.
In the past, Ive sprayed brake cleaner in the lines and blew them out several times (from both directions) it helps to have a "helper" hold their fingers by the lines to tell you the air pressure coming out (gives you an idea of any blockages).

 

It is a 79 Dodge Magnum not a Magnum engine. What I do is unhook the fuel line at the fuel tank hook a hose to that a start a siphon to drain the tank for removal..On a lift makes this real easy...There is no drain plug but one can be installed is wanted. You can use a transmission drain plug kit after the tank is removed...As far as the lines go just unhook each end and pump fresh gas through..Bill

 

Yes, I know.
I'm very aware its a magnum (car), not the motor.
Hence,
the pic of a magnum in his avatar and,
the fact that he clearly says in his first post 79 magnum lol.

 

Thanks for the advice guys. I assumed I'd need to take it off. Have any of you heard of using kerosene in the empty tank to break up the deposits after removing the tank, and then draining? I probably won't get around to doing any of this till the weather gets better.....would be nice to have a garage about now

 

Im a little confused then. Why did you ask if it was a throttle body???Chrysler didnt have anything throttle body until the mid 80s...Bill

 

No worries,
I was confused by your post as well,
since the magnum engines didn't come out until MUCH Later than 79. Did mopar EVER use a TB on the magnum motors?????
BUT,
I asked about a TB because I couldn't recall the first year mopar used a TB stock. (I knew it was around the 80's)

 

The first TBI were on the K cars and H/N cars (Omni,Horizon) Then they were on the Caravans. Turbo came out in 86 and was a 1st generation turbo. In 87 the 2nd generation EFI/Turbo came out due to serious drivability problems... Yes the magnum was TBI but in the 90s... Just to clear the air I am a Tech support leader/Problem solver at a Chrysler Dealership and have been employed by chrysler since the mid 70s.. I also hold a Master Tech status...Sorry if I offended you...Bill

 

No offense taken Bill,
(Takes a lot to offend me lol)
sounds like you should know your Stuff then.
As I said,
I just asked a question about the TB in my OP since I didn't recall the first year they were used, (can't learn, if you don't ask).
and I wanted to be clear that,
I knew the difference between the magnum cars and magnum motors.
In fact, I've always been a fan of the magnums and miradas.
Hey, since we're on the topic...or off topic lol
What was the first year for the MPFI on the magnum motors????
(Thinking about using one in a project)

 

Sorry I jacked your thread Miller!
I've heard of guys using, kerosene, thinner, fresh clean gas etc etc to clean out tanks before, some work better than others, I imagine your tank is going to be pretty nasty inside....give it a try and see if it works and if it doesn't do a real good job, step up to something stronger and repeat, its a smelly nasty job.
I def understand about the weather, its gotten cold here in KS as well, time to hibernate!

 

The 3.9 was a magnum engine and in 92 they were MPI..So 92 was the first year for MPI on the magnum V6 or V8 I'm not sure which one you are looking for...Bill

 

you could just siphon the gas out And for cleaning the lines if I were you I would completely replace the lines and either rebuild the carb or get an edelbrock or holly.

 

No problem Thanks, I know I have a project ahead of me when it warms up. I need to throw some cottonballs soaked in peppermint oil in the interior to make sure all the mice have jumped ship.

 

I planned on siphoning most of it out before dropping it. I know the tank will need cleaning inside as well. If I can find the lines cheap I'd rather replace also and I know the carb will have to come apart as the motorcycle carb I just rebuilt had been sitting for 15 yrs or so with old gas and the jets were totally clogged on one side.....carb dip does wonders! I'll just have to find a place to get all the rubber/gaskets for the carb rebuild for hopefully a fair price. Any suggestions on places to buy the lines and the gasket/o-ring kits?

 

Some radiator shops can still boil and flush fuel tanks.
Outwears around here will also pressure test them for leaks...
Just food for thought...

 

Not entirely sure but I believe as early as 93-94. The first year of the 360 magnum. The only TB magnum was the early gen 318 mag?

 

Siphoning gas is old school, and dangerous...you can inhale or swallow it if you don't know what you are doing...daughter had a kid in the ER and ICU for doing it last year...I know...we all used to do it...however...you don't have too...

I made a fuel drain kit...I am a Charter Capt and work on boats as well...removing a tank in a boat is NOT AN EASY thing to do...especially if that tank is glassed in and holds 200 gallons of stale gas thats turned bad...hint...have a few 55 gallon drums handy and make friends with the local Volunteer Fire Departments for fuel to start their training fires...

Went parts store...bought electric fuel pump for a Chevy truck...the external one that looks like a big filter with wires hanging off of it...

Added 3' of hose on the "OUTPUT" side and 10' of hose on the "INTAKE" side, added 15 feet of orange extension cord and HD alligator clips to get the battery and sparks (possibly) away from fumes...bolted the fuel pump to a 8"x8" piece of 3/4" marine plywood.

I "power drain" old fuel from a boat (or car via the fuel line prior to the filter) at about a gallon or more a minute...total cost of the set up was about $50...If the zombie apocalypse ever happens the kit can be lengthened, add a hose clamp to the end with a 3-4 oz fishing weight to remove fuel from gas station underground tanks to and right into your BUG OUT CAR/TRUCK...

 

I wouldn't siphon by sucking on the hose, I'd use a pump. The other way I usually do it is pouring liquid in the hose while it's elevated over the tank, then quickly put it into a container at a lower point then the tank and it will suck it out.

 

Well, unfortunately,
Since that car has been sitting for 16yrs...
He can siphon the tank 100 times and it won't do any good at all.
If it was just old fuel, that'd be one thing, BUT,
Any fuel that was in that tank 16yrs ago,
has now turned into a gummy, chunky, nasty, varnish,
nothing short of completely pulling the tank and physically cleaning it out is going to do any good.