Hey guys finally got my 92 f250 put back together this includes replacing the entire fuel system except the tanks. I had filled both tanks up before she blew the head gaskets back in 14' and didn't have anywhere to dispose of all that diesel. I get her running and burn through most of the front tank and everything runs perfect and then I switch to the rear tank and I start having problems! The guage is going haywire when on the rear tank it gets hard to start all the time have to give half throttle to get her to fire, sometimes dies at red lights and this morning she wouldn't start! Checked power to the IP and all was good cracked a line at an injector loose and nothing. Made shure I was getting fuel to the filter housing. So next I crack the feed line to the IP and get barely a trickle I pull the filter off and find a glob of black tar in the bottom, and specks of it all along the top of the filter and its quite heavy so its definately stopped up. I would say its the same consistancy as Road tar. I've done some research and I don't think its Algae and that it might actually be asphaltene which seems to be a condition this new diesel fuel that we have now can get. Is there a way I can clean the tank without replacing it? I can get a new tank cheap enough but the problem is not wanting to drop a full tank! Anyway has anyone else run into this "black tar" ?

 

I have been reading about this new #2 diesel and how it breaks down, I would say siphon it out into 5 gallon buckets and give it away to a friend for burning, then drop and use a scotch bright pad and clean that sucker out. If it's rusty maybe bump up to an sos pad.

I had similar crud in my filter when I ran wmo, really sucks how expensive these fuel filters are.

Even if you pulled the bed the tank will only drop through the bottom, at least my 91 was that way

 

I actually work for an auto parts store so I can get a brand new tank for about $100. Although I'm not shure how easy the sending units are to get. I do have access to a 91 Parts truck that I can rob the tanks off of if there good. Are the sending units the same between the two trucks? Mine is an early 92, it uses the 91 style ac compressor and belt system but is the later bodystyle

 

It sounds like algae get some biocide that will kill it. You will go thru a lot of filters. The rear tank can be a pain to drop. There is very little room to get to the connections. If you can pull the bed it easy to get to

 

Condensation could have accumulated water in the tank.
Haven't heard of the fuel breaking down.
I use used fryer oil and get algae/bacteria problems in the summer sometimes.
This works well:
https://www.summitracing.com/parts/luc-10177-1

 

I have seen this before. The whole tank was full of the crap. Looked like you could fill pot holes with the stuff. We must have put 5 filters on it before we caught on that there was more going on. It would run great, then plug up.

Similar circumstances, truck sat for a while, tank was full, crap was disgusting. He just ended up rigging up a different set up for the tank. I will say, the filter system on this truck is very effective, cause I don't think it would have ended well if it got into the IP.

 

When you remove the tank you can take it to a radiator shop and have it boiled clean. At the very least consider using this to coat the inside of the tank after siphoning out the crud:


POR 15 Fuel Tank Repair Kit


I used this kit to restore the fuel tank on my 71 Olds 98. I'm also planning on restoring the tanks in my IDI. I have a kit sitting on the shelf in my shop now. This stuff works great! Just make sure you were a respirator. It's nasty stuff!