I'm working on a 1985 6.9 and the problem I was having was it would start and have a rough time staying running eventually got to the point where it shut off whenever I was driving maybe 3 miles in or so and so I pull the fuel filter and it was clogged with rust and whatnot i drop the front tank and power washed it out with just hot water and now it's currently about dried and I found the foot on the fuel sending unit was broke off in the bottom of the tank I have a tank for 88 gas pickup and brand newnsending unit similar to go with it. . But I was wondering if anyone knew if I could use that style of sending unit on my 1985 6.9.
The spare tank is clean and if not then if I could jerry-rigged some thing up for the time being. I forgot to mention I left the rear tank in haven't messed with it but probably just as dirty an I also added a cheap universal electric fuel pump cause after I drove it home I Im gussing it ran outta fuel due to the sending unit being broke.
I don't have any money to spend for my income relies on my truck and I'm running out of time money and options any advice or help would be great thanks.

 

The 4 pin gasoline sending unit works fine to replace the 2 pin diesel unit.

https://www.oilburners.net/threads/f...p.52715/page-2

You did the right thing power washing the fuel tank. If you have the money youu can restore it with a kit like this:


Then all you have to do is paint the exterior with Rust-O-Leum and the tank will be as good as new.

Make sure you replace that fuel filter since it had a bunch of crud in it. You can also fill the new filter with ATF to act as a cleaner for your IP and injectors.

 

I got a spare tank but I got from the gas as well that doesnt have rust and it's a lot better shape then the diesel tank I have but it doesn't have that extra brace for the plastic hose that comes with in the diesel tank you know how there's like a separate whole or that plastic hose inside the rubber filler neck. The gas tank don't have that but there's exact same an how would I convert the 2 pin to the 4 pin

 

Also do I need the inline pump I was using with the old style sending unit if I have the 4 pin 88 gas sending unit with the pump attached or am I better off going the old sending unit and inline electric pump I already have on it route I just need too figure something out that's not going to cost me literally anyting cuz I'm out of money for sure as I mentioned before but I also want to do what's going to be good for the long run cuz this is my everyday truck and work truck

 

80-86 and 87-97 fuel gauges read in opposite directions and they are also the wrong resistance, your 85 unit should fit that 88 tank if you just need a tank

The foot you found broken off in the bottom I'm assuming is the shower head/strainer? If so just use a piece of hose and extend your unit to the bottom, cut a v notch so it doesn't suck up against the bottom

 

do not rely on that cheap electric fuel pump, they only last a few weeks, or sometimes months before they die from pumping diesel fuel.
and do not use the gas engine in tank fuel pump, they tend to run higher pressure than the diesel wants and will eventually rupture the diaphragm in the mechanical lift pump and fill the engine oil pan with diesel. this will in turn destroy the engine if run with thinned out oil for any length of time.
if you want to run an electric fuel pump, spend the $100 and buy a facet duralift #40222 pump. they are designed for diesel use and will last forever.

 

The only difference between fuel tanks for different years and engine types is the mounting ring for the fuel sender. The fuel senders are all over the map and I found that locating the correct one was extremely difficult, most places list part numbers by year and engine but don't tell you what the actual difference in configuration and sender resistance is. That being said as long as it an inlet and outlet you can find a way to get to fuel lines on and get it running. Some may require you to fabricate a pickup tube extension to reach the bottom of the tank.

I put a front sending unit from a different year gas engine in my truck, I had to cut the mounting ring and fabricate a pickup. The resistance ended up being different so I installed a second fuel gauge for the front tank, which worked for a few years until the sender died, now I just go by mileage from a full fill.

 

I went ahead and put the old tank back in the gas tank on the inlet had a little bracket for the plastic hose to Rest in and on the new tank it didn't have that plus the other tank to the gas truck needed to go back in it for it would run as well belong to my dad so with the old tank back in and old sending unit I hooked up the lines put a couple inches clear vinyl hose inside rubber fuel hose betwee the hard plastic for future trouble shooting. I got a electric Bosch inline fuel pump I pulled off another 88 automatic 460 parts truck my dad has an it works haven't mounted it yet but it's definitely a lots better quality than the universal part store brand. I like the electric pump cause there's less back involved priming (I think). Now I'm kinda at a standstill cause the fuel I have is whatever I drained before I still have 0$ an I wad gonna run it through filters an electric pump to pump it I .Tank but how can I filter the water? I think I have the stock separator that came with. The guy I bought it from a couple years ago said he bypassed it xauca the common air intrusion problem but it's probably best to have one on there long run I live in SW Colorado so more cold months than most places thanks for all the advice

 

the electric pump form the 88 will not work, way too much pressure. you need a pump made for use with diesel fuel, and only 7 PSI low pressure to 11 PSI maximum pressure.

 

Pre 90 had two pumps, a low pressure intank transfer pump, and a high pressure frame mounted pump (most likely what you have)

I don't know the specifics about the intank pump psi but it may work if its low enough pressure. Google is your friend here

 

I'll post a pic I don't know where to find the psi but it is lsblabe also I gotta Napa 3123: water sepsepator filter that was mounted in the truck already any advice on that would be appreciated

 

 

Also there's a little valve on top of the water separator housing what's that for?
​​​​​​

 

The valve at the bottom of the water separator allows you to drain the water. The OE water separators had a pull ring that opened a valve to drain water. They were notorious for air intrusion.

 

Mine is I believe a aftermarket from Napa I need help figuring out the screw right here on the housing I'm thinking it's a blender screw but I barely touched it testing the filter out an diesel came out for a sec I tried turning it to stop an didn't take much to quit not sure if that was from me or not it was a split second. But diesel continue to flow properly after that . Also how often do I drain that an fully chang it out?