1991 Subaru Liberty Fuel Pump Problems

[Zara]

I have a 1991 Subaru Liberty which was owned by my Great Aunt from new.  Its first fuel pump lasted about 19 years.  We have had the car since 2009 and it has had 4 fuel pumps in that time, now requiring its 5th.  I've used original and non-original parts and nothing seems to make any difference.  Between 12 and 16 months the fuel pump stops working.

 

The car does approximately 4000kms a year and has done 137,000 in total.

 

Does anyone have any idea what could be the problem?

 

One faulty fuel pump I could understand.  But I cannot understand 5.  

 

This is my first ever post on any type of forum so I apologise if I've posted in the wrong area or done something else that's incorrect.

 

Many thanks.

 

Zara

[Fairtax4me]

Water is a fuel pump killer. When a car sits for long periods water can condense inside the fuel tank and build up. The pump sits at the bottom of the tank and if there is water it will cause the pump to corrode inside and cause it to seize.

 

Fuel system problems have become much more prevalent with today's uses of Ethanol in gasoline. Ethanol absorbs water to an extent, but only to a certain point, then ALL of the water separates out.

Ethanol itself is also corrosive to many metal parts in the fuel system.

 

If the car won't be used every day, start using a fuel stabilizer when you fill the tank. That should help prolong the life of your fuel pump.

[naru]

Possibly a partially plugged in tank strainer or downstream fuel filter or a dirty/rusty fuel tank.

Are the filters still free flowing at pump failure time? You are replacing them right?

 

Pump warranties normally require that you replace filter and strainer and wash out the tank.

 

Some folks claim high sulphur fuel can be a problem.

 

I suggest dissecting a dead pump to pinpoint the failure.(worn commutators on ones I looked at).