no problem helping , most of us enjoy helping others with our hobby / addiction whatever , why we'll even give advice free on a golf course , no need to make an appointment at the office . ( you won't catch me chasing a little white ball all over hell and creation tho ) 

 

Thank you so much for those links!  You solved some serious googling issues I was having about correct parts lol.  When I originally saw the condition of the sending unit I considered replacing it.  But after some information gathering reading some older threads on here, it seems a few people have had issues with aftermarket replacements.  And since I have a known working unit, theres no reason not to clean and refurb it a bit.  Thank you so much for those links. 

I also took dodge82273's advice and blew out the lines with an air hose.  I took a old white shirt and had someone hold it on the line while I blew air down.  While nothing horrible came out of the line, there was some black splatter on the shirt that came shooting out of there with the gas.  I have my tank ready to go, and once I have my sending unit and rubber lines fixed I am going to get it all back together and do one more fuel filter replace just to be sure.  They are cheap enough anyways.  I can not explain how helpful this forum has been. I've had to fix a million things on this truck since I've gotten it,  and this site has helped me tackle every single one.  I believe I am finally on this trucks last problem,  for now at least lol. 

 

definitely replace the rubber lines from the sender to the frame while the tank is out

https://www.classicparts.com/1967-87-Gas-Tank-Sender-Unit-Sock-Filter-3_8/productinfo/23-598/

https://www.amazon.com/Airtex-FS253-Universal-Sending-Strainer/dp/B006I441LQ/ref=sr_1_1?keywords=fs253&qid=1579222173&s=automotive&sr=1-1

https://www.amazon.com/Omix-Ada-17728-02-In-Tank-Fuel-Filter/dp/B003AOGFLQ/ref=pd_cp_263_4/145-0238639-4615974?_encoding=UTF8&pd_rd_i=B003AOGFLQ&pd_rd_r=54ee3466-da65-4980-a20b-237067d31d49&pd_rd_w=s7QXw&pd_rd_wg=hrHSW&pf_rd_p=8b7a1fd1-136c-4b2c-8fd7-681e38610ce2&pf_rd_r=4VEW0R91WX2Z8S6S0KM7&psc=1&refRID=4VEW0R91WX2Z8S6S0KM7

 

your filter is by the engine ...? replace it , and then do it again after a day or so , otherwize remove hose into filter blow compressed air thru and reassemble  .... try to catch the gas , no sparks or open flames ...

 

Well I finally got a chance to drop the tank on the Ramcharger and I will say it went a lot easier than I expected it to go.  While siphoning the gas out I noticed that the gas was a little discolored.  After I got the tank off I immediately saw the lines going in were shot.  To the point I can't believe this thing wasn't leaking gas.  I pulled out the sending unit and if it came with a sock on it, it had long ago disintegrated as well as the entire thing being covered in a nasty film.  I filled the tank with some water, sloshed it around a bit and you wouldn't believe what came out of it.  What looks like a combination of rust, mud and black mess that I can only assume is what's left of gas that was left to break down.  I spent a good couple of days thoroughly cleaning the tank, and sending unit.  Given how bad it was I can only imagine that at least some of this stuff has made its way through the fuel lines on this truck.    The rest of the lines look good as far as I can tell.  Is there a way to reliably flush out the fuel lines or is it best to just go ahead and replace them since I'm already this far in?

 

Good call.  I haven't dropped the tank yet to really catch the fact its plastic.  I've used that stuff to great effect on other metal tanks but I do believe you are right that it wouldn't go well on a plastic one lol

 

I am probably going to go ahead and use one of those por fuel tank cleaning and sealant kits while I have it off.

its a PLASTIC tank you,ll end up with a bowl of jello use,in that sh!t

 

It does have a mechanical fuel pump bolted onto the engine.      I spent a good couple hours checking for shorts and bad grounds, and was not able to find anything,  however that doesn't mean I missed something.  I traced the fuel lines back to the tank, and while they are dirty and likely the original fuel lines I don't see anything in a position that could be getting pinched, and I don't see or feel any leaks or rust, at least what I can see from laying on the ground.  Once we finally get some clear weather here I am going to drop the tank and check the lines going in to the tank, as well as the sending unit and the integrity of the tanks interior.  I am probably going to go ahead and use one of those por fuel tank cleaning and sealant kits while I have it off.  This thing would wait until it was full of gas to give me problems lol. 

 

an '87 with a 2 barrel CARB ... ok so your saying you have a mechanical fuel pump bolted to the front of the engine?
  if yes , then I'd be looking for an AIR leak somewhere between that pump and the fuel tank . rust normally occurs at the top of the tank where the steel lines go into the tank . The elbow often rots a very small hole , you are not going to see wet gas , yet , it will allow air to be drawn in by the vacume created by the pump ... leading to air but no gas in the carb . any dry rotted rubber hoses , or rusted steel line can cause this , elbow is just a dirt collector common rot spot ....

 

l,d check grounds or a short

agree. I didn't read carefully about the sporadic part. Likely more electrical.

 

l,d check grounds or a short

 

I find it very unlikely for you to have 3 bad fuel pumps in such a short time. I'd think more likely you have a failing line or fuel pick up, and a fresh pump has a little more suction than one that's slightly used. You should look as your fuel lines as already suggested, but I'd go a step further and drop the tank and inspect the pickup in the tank.

 

I would take a look at the fuel line for any place it may be getting pinched when the frame flexes or the cab shifts.