club.liberty.asn.au

Had an interesting issue today..

While travelling through the Burnley tunnel (worst timing ever!), the RB starts spluttering, loses power then the engine dies for a moment before firing up and sputtering again. Did this twice before returning to normal.

Felt exactly like it was running out for fuel, but the Distance to Empty was showing 30kms left.

Once it settled down the fuel gauge continued to show more than 1/4 tank but the low fuel light was now on and Distance to Empty showed '--'.

I did put fuel in it earlier today (98RON) from a servo I don't normally use, so I though it may have some water in the fuel. Pulled the fuel pump assembly out and stripped it, no water? All I could see was some fine metal flakes sitting in the bottom of the swirl pot, so this suggests the pump may be on the way out. Tested the resistance on the level sensor and it seems fine. (still need to test the sub-sensor)

I think I'll replace the pump and filter just to be sure but, I don't think this will solve the low fuel light issue.



Has anyone experienced this before?


Car is a MY07 30RB 6sp wagon.
MIL did not come on.

Have you had your fuel pump harness recall inspection done?

I did the fix on a mates H6 outback a few years ago, similar symptoms to yours, easily fixed with a s/h pump top assy from the self serve wreckers. Burnt pins on the pump top assy plug.

I vaguely remember the intank filter and or pump being 100k service items, I did mine at 160ks, meaning I’d just about be ready to pull the trigger again

The fuel sender wires go through the same loom iirc, perhaps that’s related.
Definitely worth pulling the lot for inspection.

Definitely hit up the self serve wreckers for compatible models, and so you can pull it all without damaging the sender which is clipped to the side of the assy.

I think the postfl GT DTE is self calibrating, eg I filled my tank to the lip once and it threw out DTE for the next few normally filled tanks.

As far as I'm aware the harness recall is for 4cyl only. Pretty sure when the dealer checked my airbag, no other recalls came up.

Pins look OK, possibly due to the pump being PWM controlled.

I've pulled both fuel senders out and the resistances between full and empty are more or less within spec. As they are wired is series, I think I'll dummy two resistors that match 1/2 tank onto the plugs and see if the low fuel light goes out.

I agree, changing pumps between 150-200K is a good insurance move along with regular fuel filter changes. I'm in the process of sourcing one, unfortunately Partsoq is currently out of stock so I'll have to go local.

Interesting about DTE thanks. I'll keep an eye on what it does if/when I fix it.

Just downloaded the fuel pump wiring recall spreadsheet from ACCC, I'm not on it.

Hard to believe the sender issue isn’t related to the conking out event.

How brown is the filter and pump assy hardware?

I’d be checking every related wiring connection on the pump assy and peeping the sender wiper tracks for wear n tear.

How old is the pump?

Do you run lower than say 10% full often?

They may be related, I need to have another look at the schematic and see what the pump and sender have in common, if anyything. IIRC they don't ever share a ground.

Filter is 30k old, pump is original (that's why I'm changing it regardless), not often it goes under 10% and inside of tank is spotless.

Sender tracks look fine, resistances are pretty much within spec (nothing that would upset it) and change smoothly from full to empty (no dips).

Points to harness issue, or the BEM just had a bad day??

DTE is user selectable iirc. Did yours reset itself? https://www.google.com.au/search?biw=32 ... OOnd-EP_5c

Couldn't find anything in the owners manual about being user selectable?
Just says it calculates DTE based on remaining fuel and consumption rate over the last 30kms.

Dummied in a pair of resistors (1 main + 1 sub) after leaving the battery disconnected for a few days. Tank now reads about 7/8 full (about right for the total resistance), low fuel light now off.
DTE still shows '--' but I'd imagine it needs fuel consumption rates to re-calculate.

I'll throw a pump and filter in it and see what it does. So far I'm thinking the pump just wigged out for a second as the low fuel light came on and the consumption rate went nuts as there was no fuel pressure/delivery.

Sounds like a good plan
And check the tank for water or debris at the same time...

Yep.

I looked when I pulled out the senders, absolutely pristine in there!

Yeah cos one tip I looked up was to put UEC (or injector cleaner?) in a full tank and run that through.
Iirc a half or third of a can of uec should do, enough to clean any gunk out of the venturi. Ref: https://www.subaruoutback.org/forums/89 ... 7242&amp=1

I don't think UEC is needed in the tank.
You would need a fair lump of crud to block the venturi! (would till run fine over 3/4 tank)


Looks like all is good with it.
Fitted a new Bosch pump (OEM is over $500 my cost!!) but had to clean the OEM screen as the Bosch ones don't fit. Screen wasn't too bad but went back in spotless. Also fitted a new MAF.

Startup it missed a bit due to new MAF readings I suspect, then cold idle was fine.

Blasted up to the servo for a splash of fuel, tank above 1/2, low fuel light off, DTE working plus my annoying little flat spot is gone thanks to the new MAF.




I'll call it fixed, but would prefer to know the cause.

Love it, diagnostic logic and possible solution noted.