Gas Tank/Fuel System

JLN5thAve

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Long Story Short -
1988 Chrysler 5th Avenue sat for 10 years with 2-3 gallons of gas in it.

Restarted, with an antivarnish cleaner - new fuel filter, distributor cap, battery, still needs work.. Fuel comes out is reddish with debris in it.. So I need - I assume - to drop the tank, clean it out and run good gas through it.. Soooo...

Any tips for removing and cleaning the tank? Any tips or suggestions that might help me avoid dropping the tank? (Not likely I know)

Any other pearls (nice pun - the name of my car is The Pearl:D) of wisdom that could be given on this issue?

Thanks!
 

jasperjacko

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Tank will have to come down. You should be able to find a new one on ebay for cheap. Replace all the rubber hose and filler neck grommet while your there.
 

BudW

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Varnish is a biggie – but what is an even bigger issue is rust (another one of those four-letter words).

If one is to store a vehicle for a period of time, it is best to either fill the fuel tank full – or run it completely empty.

I would be more wary of rust, than I would varnish. If rust is an issue – the only fix is replacement.
The good news is new fuel tanks are still being made for our cars.
Here is one source: https://www.ebay.com/itm/80-84-86-88-Plymouth-Gran-Fury-Dodge-Mirada-FUEL-TANK/370289139159?epid=1889215755&hash=item5636f3ddd7:g:3poAAOxybLpRh1-c&vxp=mtr
There are other sources, as well.

Always get a new fuel tank filler neck grommet. Factory part number is 4002010 and it shows to still be available from Chrysler. MSRP is $17.10 (US) as of April 1, 2018.
Also, reuse your existing fuel sender metal lock ring - even if a tank comes with a new lock ring. Many aftermarket lock rings don’t work well (or at all).


If you are planning on adding dual exhaust to your vehicle, sometime in the future, you might want to plan for this now. The fuel filler neck will need to be lengthened and fuel tank will need to be moved over to the Right side of car, one rib.
There should be more details about operation, if you search forums.

Attached is PDF copies out of my ’86 FSM (Factory Service Manual), which should be the same.
BudW
 

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BudW

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Rockauto.com also has new fuel tanks (for less $) and new fuel sending units as well, for sale.
 

JLN5thAve

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I dropped the tank today - and I will be removing the sending unit etc on my next work time on the car.. It has about a quarter inch of sludge in the bottom of it - however minimal rust and no leaks.. Thank you for the FSM manuals - those will be a huge help. I am not sure if I will replace the tank yet or will attempt a clean and test..

Will update on the decision if you are interested!
 

BudW

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Sludge is not fun – but at least it is better than . . .rust.

They sell new filters/screens for the fuel sender. I would get one . . .
eBay might be best location to find one.


I forgot to mention. Rubber fuel hoses have a tendency to dry rot and leak (leak air and fuel). I would recommend changing them.

There are hoses at fuel tank, at fuel pump, and there are three hoses sorta hidden where the Right fender meets the firewall area.
The hoses on suction side often get cracks in them on older cars. It is a lot easier to “suck air” than to “suck fuel” many times.
BudW
 

JLN5thAve

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Thanks for the tip - I will run through all the lines and replace what I need to. The sending unit send/receive tubes were in great shape when I took them off - not bad for factory.

Can the screen/filter be cleaned or does it have to be replaced?
 

BudW

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I shudder to say this - but it can be cleaned - but I wouldn't want to do it.

From this web site I found
Fuel tank Filter.JPG

http://billrolikenterprises.com/products.asp?cat=23&pg=14
There might be a lot of other places to get this filter – or as some people call “socks”.

They are mainly to keep the big stuff out.
What I find is they fall apart over time – leaving you with “no filter” – which is why I’m strongly recommending you replace it.
Now you know what to look for and its size (5/16”) there might be other sources for this part.
BudW

Note: I'm not going to twist your arm. Your car does have a primary fuel filter already and you might be able to get by without it or even cleaning it.
 

JLN5thAve

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Thank you BudW - I will look at the filter, and finances to see if it is something I need to do right away or could get by without.
 

JLN5thAve

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Well - filter collapsed in my hand. So I’ll need to either go no filter or replace it.

Not expensive though so probably get a new one.

F7E484E2-6DD1-40F7-AEB5-44333D67705A.jpeg


E838B4CD-47A8-4EE3-B95C-A8294CDA51BB.jpeg
 

JLN5thAve

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Also side note - the astounding amount of gunk in the fuel line on the sending unit was INSANE. I cleaned it out and now it flows like a dream.

I’m shocked the car started ever.
 

JLN5thAve

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Solved one problem for sure.. I got to finish cleaning out the tank... this was a few days ago..

Liquid pictured is a almost black red “gas”.. was 7 gallons of it in the tank.

Sludge at bottom of tank was roughly a half inch thick - I was pulling out handfuls after draining the tank. I let it dry for 3 days, dropped it a couple times on dirt and shook out 80% of the gunk. Hoping I can get away with a good rinse at a car wash and be up and running.

812E870B-73B6-4D4A-BDFB-CD377BFF02A4.jpeg


548CF02D-1B80-4143-AC0D-CA4830B6918B.jpeg


DF721613-8018-4B9C-BF5F-B16C11E812B7.jpeg
 

BudW

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Gross!

For what I can see of the outside of your fuel tank, it looks pretty good (based off of the last picture of above post).

Cheap gas, as well as ethanol (10% alcohol) does contribute to “gunk and sludge”.

Unless you go fuel injection – our cars do not/will not work well on 10% alcohol (ethanol).
The better grades of fuel has detergents in fuel that can leave a fuel system fairly clean (so a person doesn’t have to do what you are doing, again.

100% gasoline and get the good stuff (even though both do not agree with your pocket book),

Try to flush out the fuel lines (all three) – if you can, and I would recommend rebuilding or getting your existing carburetor rebuilt – for that same “gunk” will be inside of it.
BudW
 

DCAspen

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Holy sludged gas tank,Batman.That tank was nasty,I hope you can get the rest of the crud out.
 

JLN5thAve

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I concur.

I’m sure you don’t want to do this, again.
BudW

That’s my only concern - getting all that crud out.. I’ve flaked a ton of it out but I think I’ll have to resort to acetone or dawn.. then a pressure wash at the car wash.
 

4speedjim

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After seeing this, and the price of a new tank, I'm ordering a new tank when I swap drivelines. They look beautiful from under the car, don't they? I'm sure mine is as bad as yours. Not that I have the extra $100, but I don't want the headaches. Or diminished capacity. I'm going to need every drop. Wish I didn't see this!
Replacing everything before you put the tank back up makes good sense. Hoses filters tank grommets are cheap. I wouldn't want to drop it a second time over a $12, or $100 part.
What sending unit would you use for 3/8" lines in our cars? Will that feed 500HP?
 

BudW

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I'm ordering a new tank when I swap drivelines.
That was the reason I recommended to find a replacement tank, to begin with. 30-40 years is hard on a fuel tank. And for $100 or so, it is not worth the hassle.

They didn’t make any fuel senders for FMJ’s with 3/8” fuel sender (or fuel lines).
A person could make an existing (used or new) sender (5/16”) and convert it to 3/8” for a bit in materials and your sweat – which might not be a bad idea for a high HP car.
BudW
 
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