3 dead fuel pumps in 3 weeks, why?

[elliusoopius]

As stated in the title, I have a '95 legacy that has gone through 3 fuel pumps in 3 weeks.

I bought the car about a year ago and it's been really reliable until about 3 weeks ago, when my partner parked it after work and the next morning it would just crank over, or start for a few seconds and then sputter and stall. There were no symptoms before he parked it. I diagnosed it as a bad fuel pump and replaced it with one from a '97 legacy that has a bad transmission and has been sitting for a year. The car started up fine and ran until a couple days ago when I was on a hundred or so mile trip. It ran fine until I stopped to get some food, then just wouldn't start, or would start then sputter and stall exactly like before, so I figured it must be the fuel pump since it had been sitting for so long, and replaced it again, this time with a new one from Autozone. Once again, the car started up and ran fine, aside from one little hiccup where I figured there was some air in the fuel line.

I got where I was going and moved the car a few times over the weekend, but put almost no miles on it until I was on my way home today.  After about 50 or 60 miles I was heading uphill over a mountain pass and pulled over to check something in the back of the car, then when I got back on the road it started to sputter like it wasn't getting gas and I pulled over to the side of the road as the car stalled out. I started it up again and made it about 100' before it started sputtering more and I pulled over again, but this time it recovered without killing the engine and I decided to try to limp it home. Over the next 40 miles it sputtered and lost power a few more times but would recover after a few seconds and I was able to make it home. 

I'm thinking there's a good possibility that my 3rd pump is gonna eat it soon and I really don't want it to be during my drive to work for the first day of my brand new job on Tuesday, so I'm trying to figure out whats causing these pump problems and hopefully get it sorted tomorrow. I did some googling and couldn't find anyone going through multiple fuel pumps in a legacy like this and I remember reading that they aren't a common item to fail in this car.

Here are some things I have done when I was troubleshooting the pump the first time:

     checked fuel pressure with a gauge before and after the filter, readings were the same, about 10 psi.

     blew through the fuel filter backwards, some dirty looking stuff came out, but it wasn't difficult at all.

     checked the wiring to the fuel pump wiring harness and the harness itself with a test light, making sure there was juice for 1-2 seconds when turning the key on. 

      

here are my thoughts on what could be causing it:

     I just have bad luck and the pump from my other car and the aftermarket one are both shitty.

     Something contaminating my fuel.

     electrical problems?

 

Does anyone have anything to add to these possible causes or suggestions for ways that I can test them or rule them out?

Thanks!

   

[ronemus]

fuel pressure  of 10 psi is way too low.  You may have a crimped fuel line or a plugged screen in the tank.

[GeneralDisorder]

Either there is too much back pressure (filter) on the pump, or more likely given your pressure readings, you have a voltage drop in the circuit, causing the pump to run slow. This is not good for the pump, or for the wiring. You might also check the voltage, voltage drop, and determine no problems which is likely going to point to a bad fuel pressure regulator, or leaking injector, etc causing low pressure....

Also used pumps are not reliable, nor are Autozone parts. Geta proper AEM or Deatschwerks in tank pump for like an 02 WRX.

But check that the system can maintain a proper pressure. Should be about 35 psi with the regulator vacuum unplugged.

GD

[naru2]

On 5/5/2019 at 8:43 PM, elliusoopius said:

As stated in the title, I have a '95 legacy that has gone through 3 fuel pumps in 3 weeks.

Here are some things I have done when I was troubleshooting the pump the first time:

     checked fuel pressure with a gauge before and after the filter, readings were the same, about 10 psi.

     blew through the fuel filter backwards, some dirty looking stuff came out, but it wasn't difficult at all.

     checked the wiring to the fuel pump wiring harness and the harness itself with a test light, making sure there was juice for 1-2 seconds when turning the key on. 

 

Does anyone have anything to add to these possible causes or suggestions for ways that I can test them or rule them out?

Thanks!

   

OK,but,what is the pressure  on the 2nd and 3rd pumps?

Fuel flows forward thru the filter,not backwards.Blowing backwards proves nothing

Your not even changing fuel filters??? Shame on you.

I suppose there is not much point asking if you changed strainers.You NEED to.

I once repaired a car that was on its 4th $400 fuel pump in a short time  by relpacing the  $8 strainer the previous  mechanic did not.

The old one appeared perfect and was absolutely free to blow thru.

You need to measure voltages at pump positive and negative.A test light does not cut it.

Dirt in the tank will kill pumps.

Last Legacy I saw w/pump problems had water in the tank.