'95 Legacy Intermittent Fuel Pump Start

subaru
legacy

#1

I have a '95 legacy wagon which has a peculiar problem. 9/10 the car starts just fine but once in a blue moon when I go to start the car the fuel pump won’t turn on and the engine will get starved of fuel and shutoff immediately after starting. Turning the key will not turn the fuel pump on and you have to wait about 20-40 minutes after which the fuel pump turns on with the key and the car starts right up. Once the car is running the fuel pump never has an issue, it just won’t turn on at start occasionally.

I’ve replaced the fuel pump relay and cleaned out the connection to the fuel pump itself to no avail. I can’t imagine the fuel pump is failing because the car runs like a dream once the pump turns on and its never failed while operating. It simply doesn’t turn on at start occasionally. Today I ran into the problem, waited 20 minutes in the parking lot and it started working again. Drove the car home, shut it off and restarted it immediately and the fuel pump didn’t turn on.

I’m at a loss so if anybody has had this problem before or a hunch about fixing it please let me know.


#2

Another note: I thought the problem was solved after cleaning the connection to the fuel pump a week ago but it happened for the first time again today. Sometimes I go a week without no issue, sometimes it happens every couple of days.


#3

It’s not uncommon for a fuel pump to fail intermittently in the manner you describe.


#4

Interesting, I figured if the pump was going bad I’d encounter issues while the engine was running at some point. Still, I was worried that might be the issue. I just wish I could diagnose and confirm that in some way. I’d rather not just cross my fingers and drop $100+ on a fix that MIGHT work.


#5

The next time it doesn’t start, immediately get out, slide under the car, and pound on the bottom of the gas tank with your fist. If it then starts…most likely fuel pump.


#6

Started my car to see if the problem was back to test it but the fuel pump engaged and the car started. However, the engine immediately starved right after and the fuel pump won’t start now. Banging on the fuel tank didn’t change anything but in light of the recent developments I’m pretty convinced you’re right.

Now I’m looking at fuel pumps and I’m wondering if an aftermarket pump would work fine. Its an old beater with 273,000 miles on her so I’m looking for cheap and functional. But I’m sceptical when the OEM runs $250 but stuff like this is only $30: https://www.partsgeek.com/catalog/1995/subaru/legacy/fuel_delivery/fuel_pump.html

Does anybody know if its okay to cheap out on the pump for a cheap car or am I gonna end up just replacing it again in 6 months? Is there a particular aftermarket brand I should be looking out for? Thanks again for your help.


#7

Also I did the hammer trick again and the pump started running again. Its definitely the source of my problems.


#8

Are you replacing it yourself? If so, you could throw a new $30 pump in every 6 months for 4 years and still be money ahead. I’d guess that cheap pump will give you good service.


#9

If the pump is hard to change, I’d get the OEM or at least a decent brand name pump. Ask how I know. Dropping the tank in the driveway isn’t fun.


#10

Rockauto shows the Bosch pump as OEM for $92, they also have Delphi, which is a good brand, for $60-$90, Carter pumps for $45-$52


#11

Thanks for the advice everybody! Fortunately the fuel pump is very easy to replace. There’s an access panel for the fuel pump right behind the rear seats (and its a wagon so I’ve got plenty of room to work with). Pop a few screws and 4 bolts and I can just pull the pump right out. I guess I’m going cheap because pulling this thing out is pretty easy.


#12

You’re lucky to have an access panel, go cheap then if you want. I still wouldn’t get that pump you showed. I had a cheapo pump recently that sounded like a hair dryer under my car and the RF from the pump bled over my radio.


#13

I’ll jump on a delphi. Thanks for the advice.


#14

I’m wondering of the vehicle has an inertia switch to shut the pump off in the event of an accident. If so, that could be malfunctioning.
Or perhaps the pump relay has developed carbon on its contacts and is operating intermittently.

Have you checked these possibilities out?


#15

The inertia switch and relay (which has already been replaced once) can be ruled out by measuring the voltage right at the pump connector (by back-probing, everything connected). If it measure 12 volts or so and the pump isn’t starting, almost certainly the pump is the cause. Pumps not starting , especially when the engine is warm, is a pretty common problem reported here. I’m guessing a new pump will fix it. If you are unsure which brand of pump to use, take a chance on one in the middle of the price range, not the cheapest, and not the most expensive. Ask the parts store if they have a pump test fixture too. Then you can have them try it out before you go to the bother of installing it. Subaru did you a big favor by providing that access panel btw :slight_smile:


#16

Whoops, forgot about this post. It was the fuel pump everybody, 11 months in and the Delphi is chugging away. Thanks for the help everyone!