So quick question on these dual tanks. I filled up both tanks no problem running of the rear tank with no issues, I switch to the front tank it runs for a few minutes then will die. Remove the fuel filter to see how much fuel is in it and not much, I had to bleed the air out of the system and then fires up on the rear tank and runs no problem. I physically cannot see a leak around the fuel lines or tank. Vehicle is a 85 F250 4x4 6.9 thank you for any advice

 

Sounds like a broken fuel pickup inside the tank. It is a common problem on these trucks.

 

Ya I was afraid of that., looks like I'll be pulling the tank today to inspect, these tanks are 19 gallon?

 

Yep, both tanks are 19 gallons.

The common failure is the Cone of Fail at the end of the pickup tube itself, but that only affects fuel pickup at around 1/4 of a tank.

If your tank is full and the problem is indeed in the pickup, then there's a problem with the tube itself which isn't as common, but can happen if corrosion is present.

Here's the Cone of Failure:

https://www.ford-trucks.com/forums/1...l#post12907382

 

So I finally got around to trying to solve my front tank not working... Well before I even dropped the tank I pulled the sending unit out and this is what I got

A whole bunch of rust!




So if one were to have a clean tank should the pick up to be the same length as the return?


Needless to say I don't think I'm going to use this front tank simply because the amount of rust in it from what I can see, I will just keep using the rear tank I am getting clear clean fuel out of that minus the additive that I put in.

 

THANKS!!! I think my truck is doing the exact same thing. Front tank will work for about 50-100 miles on the front tank, then will run out of fuel. I'm sure it's doing the same thing as yours from the looks of it.

Are you sure that's rust? Lately, I've been concerned about algae in my tanks. I think that the front (because I can't use the fuel) probably has a ton of the stuff in it just having a party in the diesel that never leaves that tank. I'm going to drop that tank, clean it out well, SHOCK the #($"* out of it, and then start driving it again, after of course I fix the pick up tube for the front tank.

Let me know if you think that stuff may be algae. Later.

 

No, it is too short. Check out that link I posted above, your Cone of Failure is broken off and is somewhere in the bottom of your tank. You either need to replace it or add some hose. Both solutions are in the link above.

 

I was reading that, was going to ask you how long that piece of hose was?

 

I have a new cone here and it's 3 1/2" long.

 

Cool thanks, I'm going to drop the tank tomorrow and see if I can clean that crap out of there. I don't know if it's rust or algae

 

My truck is acting exactly the same but in both fuel tanks. How is that possible for both tanks at the same time? Both are at a quarter tank too. I already replaced the pump and filter.

 

All of these IDI trucks are at least 20 years old. Over that time the cones have become brittle and broke or cracked. Not unheard of for both to fail, both of the ones in my '85 did.