How to Diagnose a Bad Fuel Pump 1996 Subaru Legacy 2.2L Pt. 2 Diagnose

[@Modeltnick]

I just replaced the pump on my 2007 Forester. It gradually went bad causing a variety of misleading symptoms like causing the care to go into limp mode and throwing TCM codes. Finally got stuck and towed. Good thorough video!

[@Alniemi]

yeah i just got towed home tonight for my fuel pump in my 96 outback. That explains the random surges and dips in power over the last couple months. I pulled it out and its the ORIGINAL pump manufactured in 95!!

[@richardpare3538]

Be aware that the '96 may have come with wiring that is different than the poster has shown. It looks like some of the cars in the early part of the build still have the '95 2 connectors under the seat arrangement where the 2 power wires for the pump are in their own 2-wire connector.

[@bret5850]

I got a resistance reading of 34 on the green wire of the sub harness. The black/red wire on the main harness has power. Does that mean I need to replace that sub harness?

[@KNKRNR]

No, but you need to check battery voltage at the sub connector. Say if your battery voltage at the battery is 12.39 VDC and your sub connector is 12.30 V DC your okay its normal to have some resistance. If you see below 12 volts at the sub connector and your battery voltage is 12.39 then I would say to replace your sub connector or find where your dropping voltage and fix the wiring issue at hand. You really want the voltage to be the same from the battery to the fuel pump. /K&K

[@HellofromAustralia-s8h-juan]

Can a pump issue cause bad idle? Like up and down idle but not completely stall?

[@KNKRNR]

Not likely, the Idle air control motor on those engines likes to get sticky and slow. As the engine ECU corrects the idle as it should it starts to idle hunt. If you give it a little throttle and it holds steady you need to look your idle air control motor. /K&K

[@275erz]

Thanks for the video, Where can we find the fuel pump relay?

[@KNKRNR]

Yeah its not easy to get at but its right under the dash near the A pillar. Check out the link below. www.google.com/search?client=firefox-b-1-d&q=where+is+the+fuel+pump+relay+1996+subaru+legacy#kpvalbx=_BW1PYo36DO_SkPIP_MuMqAY14 /K&K

[@deb52able]

I have a 05 subaru outback 2.5 xt. Where is the inertia switch located on it?

[@KNKRNR]

Good news Subaru's do not have this feature. Ford was the only auto maker I know of that used an in trunk or glove box inertia switch. Most auto makers saw the trouble that Ford had with them and decided otherwise. /K&K

[@nealwyms2067]

At least you don't have to drop the tank

[@iamDavidduh]

I'm having a issue with my 05 wrx I did the continuity check and each wire was conducting properly and were not beeping more than once per pin. The problem is when I used the test light I found that it stayed on when the key was only suposse to prime the car. This happened when I tested the front and rear harness so I'm thinking it's something faulty on the front of the car. I'm wondering if this is a bad fuel pump relay, ground or what? I'm stumped. I changed the spark plugs and wires and the car ran before I did that now it will start after sitting for a week but only for about 2 seconds. I'm getting a code for p0183 which was not happening when all this first started but today I checked the fuel pressure and I read 0psi. Did anything change in the new Subarus because they have a fuel pump control between the front harness and rear? I stick my ear next to the relay when turning the igniton on and I hear it click once should it click twice? Once to open then once to close? Any advice is appreciate and thanks for the awesome video it's helped me trouble shoot my problems. With out it I would be lost.

[@KNKRNR]

PO 183 Your missing the fuel temp sensor feed, grounds are not switched but the power B+ is. Those harness can give you false positive as you have a data communication line feedback to the ECU. PO183 You may be missing the ground or power feed to the sensor or the sensor went bad. No fuel pressure at all means either the fuel pump has no power or the pump is bad. If the relay is clicking that's not your issue as its working as it should if the engine does not start after 2 seconds the relay is turned off by the ECU. The fuel pump should prime for 2-4 seconds each key cycle and stop if the engine doesn't start. I would start with the fuel pump first as the engine should have fuel pressure at all times. If you have power to the pump for 2 seconds but the pump doesn't hum start there first. Subaru''s keep to their roots but connections may have been moved. I have not worked on WRX's very much as they are a specificity to their own class, but I have worked on fueling issues on many Subaru's, they do keep it simple as they do with their entire product line. You need a WRX book and good schematic(s) to trace the fuel pump connections. Test to see if the fuel pump is getting power or not. If the fuel pump has power but won't hum your pump may be bad. If you have no power feed to the pump you have an open short somewhere as your relay is working as it should. One broken pin can give you hell when trying to hunt down a connection issues. PO183 tells me you missing power or ground somewhere in the fuel pump circuit feed. Start with making sure the pump has power first. Don't start replacing parts till your test for power at the fuel pump. Replacing parts on a guess is expensive and most of the time is not the issue. After market fail sooner then O.E.M parts. WRX or not the fuel pump need power to run. PO183 plus no fuel pressure could mean both are related but not always. Test the fuel pump connection first for power as the car should run with a PO183. I hope this advise will help you find the cause of you crank / no start fueling issue. /K&K

[@iamDavidduh]

After I checked the continuity of the harnesses I hook them back together and checked the power to the fuel pump with the test light. The light fired up but never turned off during the priming stage. I checked the voltage to the 6 pin fuel pump connector and it read 12v. The fuel pump is not humming but I can hear it gurggle a little. I've never replaced the fuel filter either so I'm assuming it's dead because I do hear it slightly. I just thought was weird that the 12v wire did not turn off when the car was priming, so I went up front and took the key out of the ignition completely, unplugged the fuel pump relay, then used the test light on the 12v source and it illuminated I don't think it is suposse to be doing that . Correct me if I'm wrong this is what is confusing me the most and made me hesitant on buying a new pump... As you mentioned I may have two problems. One the pump is dead, two the pump is being over energized. I bit the bullet and ordered a new pump because I know the old one is getting power unless I'm getting a false positive. ( I'm a little confused about what a false positive is ) If that's not the case I will find out soon. I never changed the fuel filter on this car due to it being inside the tank. I've owned the WRX for 6 years and have put 75k on it. (You're suposse to change the fuel filter every 30k) These facts lead me to believe the fuel pump was straining but worked because I drove the car everyday. I parked it all summer and the pump finally rested for too long. I think it may have been strained from the fuel filter. I will let you know how it goes once I out the new parts in. If I still have the code and if it runs. Thanks for the details again I have been trying to ask for help on the nasioc forum but 500 veiwer later and I'm getting almost no help. I told them on there I have a WRX and the one guy that is trying to help me on there thinks I have a base Impreza with out a fuel pump controller...😅 Means a lot to read your detailed reply and it's time for me to subscribe thanks KK!!!! - David

[@deb52able]

Mfuel pump runs when you try to start it but won't start

[@KNKRNR]

If you have fuel pressure then you need to check the coil pack for spark. If you lose the Mass Air Flow, Crank or Cam signal this engine will not start. /K&K

[@user-sk5cv7hj2m]

20$ part just change it. It's old.

[@charlenelabarre9088]

My 91 Subaru starts then dies

[@KNKRNR]

Will it run if you keep your foot on the gas pedal 1/4 way down? If it starts and then dies it may be possible the IAC is not letting enough idle air through to run. If it runs with your foot on the gas pedal you might have a different issue at hand than the fuel pump. /K&K

[@853rudedogs2]

I found it

[@KNKRNR]

We try to keep videos in series but KZbin likes to do something different. Glad you were able to find part 2. /K&K