Yeah! another problem.... Erratic Fuel Guage , Stalling

[Blaze One]

So... I have an erratic fuel gauge , stalling , not starting at all sometimes .
Started yesterday when I thought I ran out of gas because my guage was at empty and the truck would turn over , but wouldn't start . So I put more gas in , and it started right up .
Then today , I was driving around and it almost stalled at the intersection . And then wouldn't start after turing it off , and the Fuel guage is fluctuating from E-3/4 of tank , even when on a level surface .

Fuel Pump ?
How Much ?
Fixable at home garage ?

[HenryJ]

Fuel Pump ?

Fuel pump module

How Much ?

$200-$400

Fixable at home garage ?

Sure.

[AZS10Crew]

Could have something to do with the sending unit also. That may be all one piece with the pump? We've had lots of problems lately at my dealership with erratic fuel gauge readouts. The info we've been getting from Ford is that it's due to high sulphur content in the fuel that was released into the market by the federal gov't to ease prices. The sulphur builds up on the sending units causing inaccurate readings and even stalling concerns at times.

You may want to try a good fuel system cleaner before getting the new pump/sending unit. We've had good luck with the Chevron Techron cleaner. We've run that through diesels that have used high sulphur ag fuel and they've ended up being OK. We've also been told BP stations seem to have the lowest sulphur content too FWIW.

[Blaze One]

k thanks i try the cleaner first .

[Blaze One]

Well , I didn't do anything , and the damn truck is running just as good as it ever did .
Still a little rough at idle every so often , and a squeek in the one of the Accessorie drive belt wheels .
But atleast it is running .
I am going to give it a SeaFoam treatment on Monday .

[HenryJ]

Keep replacement in mind. It is only a matter of time.
They seem to prefer dying in the parking lot of your local "everything-mart"

The pump has kindly given you fair warning, so be kind when it does strand you

[Blaze One]

Oh I know , it is a #1 priority to get it replaced before it leaves me stranded .
Just don't have the $$ right now .

[HenryJ]

Run on the top half of the tank. This maximizes the coolant available for the pump. Avoid treatments that contain coatings to keep parts clean.

Lots of times the foot valve in the pump goes. This is indicated by prolonged cold starting. It usually gets worse just before the pump fails. The performance may also degrade as the pump weakens.

When you pull the module look at the tiny fingers on the fuel sender. It is likely you will find many of them broken or worn away. I have three of them to change in the next few weeks. I'll try to get a picture as an example.

Good luck and treat that rig nice. It will repay the favor.

[Blaze One]

Thanks , Pictures would be great . I am just guessing , but the Fuel Pump Module is in the tank correct ?

[HenryJ]

Yes. It is in a plastic bucket with the fuel pump inside and the sender on the side of the bucket.

[HenryJ]

Here is a good example -



This one is from a 2000 fullsize with 99,000 miles. Ours is similar , and this one will show the problems. This one was erratic, and sometimes it did not work at all. Eventually it quit all together.
Here is a close-up-



At the top you can see the float rod. It serves as the pivot point and with time wears. This lets the assembly get loose. Below that you can see the two contacts with their tiny fingers. These ride against the printed circuit board. The tips eventually wear out and break off, or the printed contacts on the board wear off.
Another thing to note here is that the plastic starts out white. Additives and contaminants stain it brown. This coating does not help promote good contact.
Now you can see where the problems lie. Another thing to bring up here is the use of additives that coat the components. This is done to prevent the adhesion of deposits. The problem is that while insulating the formation of deposits it may also insulate the contacts preventing good contact as well?
Quite some time ago I read an article about a brand of fuel that uses an additive that coats to prevent the formation of deposits. GM was in the process of investigating if there was a relationship between this and the sticking poppets plaguing the early SFI engines. I never did read or hear more. They solved it by upgrading the spider and therefore eliminating the problem area.
Personally I think there may still be a link to the fuel sender problems. Perhaps the coating traps debris creating an abrasive surface leading to premature wear? Or the coatings interfere with proper contact? I do not have THE answer. I do avoid some brands of fuel and additives though. superstitious? Maybe?