low fuel chugging

[tigerland]

I own a '99 SD 4X4 with 114000 miles on it that I use for towing. This problem began last summer when the fuel gage registered low (like 1/8 of a tank) the engine began chugging and wouldnt run; I used to be able to run this truck until the fuel light came on but I cant even get it that close anymore. I now keep it always above the 1/4 mark because I am afraid it will not run. It acts like it is running out of gas; When this happens I can drive it but it it goes very slow and wont accelerate. When this has happens I just put more fuel in ; it takes some time to start but then it is fine. I just dont know whats the matter. What do you think?

[mako314]

just had the same problem it's caused by the vent tube in the tank injecting air. I dropped the tank and cut the vent tube as close to the tank wall as possible and wow it solved the problem I can also fill the tank much faster now

[tigerland]

Wow! How did you figure that out? Can you explain the anatomy of the tank and where the vent tube is; this sounds like big bucks; Iwas hoping it was just the fuel tank. thanks for the reply.

[vitalidle]

Use this link and scroll down to harpoon mod. Welcome to guzzle's In-tank Hutch Mod Web Page This might help ya!

[guzzle]

We're talking about two different problems here with the design of Ford's fuel tank and delivery system.

tigerland's problem has nothing to do with the venting internal to the fuel tank but rather the mixing valve design in the fuel pickup system. Ford designed into the fuel pickup foot, a valve that was supposed to help if the pickup/fuel return started to get cloged. The unintended results of Ford's design is massive amounts of air being allowed to enter the fuel delivery system as the parts aged and the tank was below 1/4 full. Combine this design flaw with the fuel line connector o-rings that work great under pressure but will also introduce air under a vacuum (pre-pump fuel lines). Hutchinagusta came up with a plan to replace the in-tank pickup system, eliminate the leaky o-rings between the tank and pump, and install a filter pre-pump to replace the mixing screens that had been removed during the in-tank modifications... i.e. "The Hutch Mod"

The vent modification that mako314 speaks of simply allows for faster topping off of the tank so the pump clicks off with only about 1 gallon of room left in the tank. It was first introduced by "Harpoon" (username) i.e. the "Harpoon Mod".

Hopefully the long-winded post clears this up a little (maybe it muddies the water?)

[SCUFFY828]

my experience with this concern is that the sending unit is not reading correctly it actually is running low on fuel, ive even seen it with models up to 05 , r&r tank and replace or adjust correctly and will operate fine , the complaint i get is will stumble and even quit after fuel gets down to a quarter of a tank , replace sender or adjust problem gone, just something to consider

[tigerland]

thanks for the help I am going to first replace the sending unit to see if this fixes the problem the other sounds like a major operation.