In the tank car fuel pumps

[cobra44]

I have been really having some problems with fuel pumps lately.
About 9 months ago a pump quit working in one car.
About 3 months ago, another one quit in a different car. And today a different car quit pumping fuel.
All 3 of these cars are not driven very much.
The question that I have - will letting cars set around kill the pump with old fuel in it?
I cannot imagine this ruining the fuel pump. I have not had any problems previously.
I am really getting tired of replacing these pumps.
Any comments? any thoughts on this?
Any information would be greatly appreciated.

 

[Spotteddog]

Old fuel. Contaminated fuel. "Augmented"* fuels (* state EPA boutique formulas). Most commonly though it's allowing the in tank electric pumps to be run while the fuel level is low. I know it's counterintuitive, but the in tank electric pumps are actually cooled by being immersed in fuel. Low fuel=low coolant.
And, get ready kids! Coming from a state house near you soon, higher than 10% ethanol content! Some will be allowing a "legal" limit @ 15%-20%. Just wait till your 5-15 YOA car's gas tank has some of that dropped into it? Now we're talkin' about all the fun you can have with your pants on!

 

[arkdweller22]

There was an issue a few years ago with in-tank pumps (especially in Chrysler vehicles) and Shell gasoline. Apparently the high sulfur content in Shell fuels caused pump failures. Apparently it was a bad combination: Modified fuels + Poorly engineered fuel pumps = Pump failures.
Chrysler did replace pumps affected however.

SpottedDog is "spot-on" (bad pun, I know...), you should switch fuels. At least until fuel mixtures get worse, and they will.

I hope this helps.

Regards,
Arkdweller

 

[gunnut2u]

My daughter just had her fuel pump replaced . The mechanic told her that the pump went out because she hadn't maintaned the fuel filter. Not for sure if this is correct , but the math does add up if it is true. Filter replacement $9.00 / pump replacement $515.00 .

 

[Stubborn Dutchman]

My daughter just had her fuel pump replaced . The mechanic told her that the pump went out because she hadn't maintaned the fuel filter. Not for sure if this is correct , but the math does add up if it is true. Filter replacement $9.00 / pump replacement $515.00 .

Plugged fuel filters will cause pump failure. The pump is stupid. It keeps trying to push fuel regardless and over heats till it dies.

 

[tomf52]

Today's fuel injection systems utilize a return system. If filter is that plugged fuel is diverted to return line (to the tank). No excessive pressure results, Pressure kept at a constant by systems' fuel pressure regulator. Dirty filter will not affect pump life although it may affect vehicle performance.

 

[41]

Today's fuel injection systems utilize a return system. If filter is that plugged fuel is diverted to return line (to the tank). No excessive pressure results, Pressure kept at a constant by systems' fuel pressure regulator. Dirty filter will not affect pump life although it may affect vehicle performance.

On GM vehicles, the pressure regulator is at the throttle body ejectors (TBE) while the filter is in line somewhere between the TBE and the pump. To maintain pressure, excess fuel is returned to the tank. If the filter is clogged, the fuel can not get to the TBE so the pressure will drop.

A clogged filter will cause high pressure at the pump and cause the pump to work harder.

41

 

[Wheelgunner840]

Since you folks seem plenty knowledgeable about this subject, I have a question. What genius decided that the fuel pump needed to go in the gas tank? It was a whole lot cheaper and easier to replace the external ones. Must have been the same guy who invented those public bathroom faucets that shut of 2 seconds after you get your hand under the water!


WG840

 

[Lee in Quartzsite]

Dirty fuel filters used to get most of the blame for in-tank fuel pump failures. Now ethanol in the gas seems to be causing problems as well, according to my local mechanic. Do a Google or Yahoo search on ethanol and fuel pumps....interesting results. Here are a few:

http://www.biofuelsdigest.com/blog2...in-new-ford-crown-victorias-and-checy-tahoes/

http://www.topix.com/forum/autos/ford-ranger/T4LLT9GCL8QEJ3N9J

http://www.examiner.com/x-7184-Char...re-ethanol-in-gasoline-and-fuel-pump-problems

 

[Bassamatic]

Why are you guys worried about this? In five years we will all be driving little asshat Fiats with electric batteries.

 

[Amici]

What genius decided that the fuel pump needed to go in the gas tank? It was a whole lot cheaper and easier to replace the external ones. Must have been the same guy who invented those public bathroom faucets that shut of 2 seconds after you get your hand under the water!

It's called "progress." As in, the progress that replaced those somewhat-easy-to-work-on-which-was-good-because-they-needed-it-often carburetors with far more efficient fuel injectors.

EFI requires high pressure, and those camshaft-driven mechanical pumps you are enamored of simply didn't provide it. The submersible fuel pumps DO.

However, they need to be IN the tank because:

1. You can't PULL gasoline at high pressure; it just turns to a vapor. It must be pressurized - read: PUSHED - to meet the needs of today's injector systems.

2. Such pumps run HOT. As already noted, putting those pumps in the tank not only achieves the pressure requirements, it also keeps the pumps cool. Aircraft have done this for decades.

Does that help?

 

[Wheelgunner840]

It helps me appreciate my 1960 Willy's Jeep that has a fuel pump that I can replace myself in 10 minutes for under $50, but thanks for the info. Always good to know.

WG840

 

[sar4937]

Wheelgunner, you're not doing your part to stimulate the economy. I guess we can blame you for the trouble we're in. Driving until the low fuel light comes on can shorten pump life. Fueling up during or just after a fuel truck has just dumped fuel can load your tank with debris and plug the strainer. And having your repair shop change your pump without flushing the tank is also bad. An incredible amount of crap come in your fuel and settles in the tank. Some new tanks are not flushable, and meant to simply be replaced if too dirty.

 

[cobra44]

Thanks for all the information.
All of these vehicles are kept at least half full.
It has to be the corrosion thing, I assume. I can replace these in about 3 hours and about 130.00. I just really hate to do the work.
I guess that I need to remove the tank, and clean it out before replacing the pumps.
I am considering putting a drain plug in the tank while I have it off. At least then I can drain any old gas out if I have to.

Also, what is the best way to clean the tank?

 

[Spotteddog]

The fuel tank drain addition is one I'd do in a heartbeat were I ever to need to pull a tank these days. The radiator shop doing the flushing out of the tank could add it easily at that time. Unfortunately, no small numbers of the things have their first (and ONLY) fuel filter around the pump in the tank? Many have a filter on a frame rail or elsewhere, but that actually is a "secondary" filter. The in tank fuel pump still has the P/U screen mesh.