CovertRussian's 05 LGT Build Thread

Finally got the fuel pump filter bypassed! Took me months to figure it out a way to do it. Here are some teaser pics, more to come after I install and test it .

 

http://i160.photobucket.com/albums/t188/covertrussian/Cars/05%20LGT/Engine/Fueling/Fuel%20Filter/SAM_7397%20-%2014in%20Hose.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/05%20LGT/Engine/Fueling/Fuel%20Filter/SAM_7490.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/05%20LGT/Engine/Fueling/Fuel%20Filter/SAM_7502.jpg~original

Hi, can I ask you a question. I have cleaned the PCV valve, looked real clean and fine. My problem is that I have blown 2 crank oil seals. When checking the second one I could have pressed it in another 1,5 mm, maybe that is why it flipped out over the edge. Anyway, how can I check if pressure is too high in engine? A friend recommended me to take off the oil filling cap and check if its puffing. Is there a better way?

Just curious. Why would you want to bypass the filter?

Just curious. Why would you want to bypass the filter?

He installed a replaceable fuel filter in the engine bay.

Hi, can I ask you a question. I have cleaned the PCV valve, looked real clean and fine. My problem is that I have blown 2 crank oil seals. When checking the second one I could have pressed it in another 1,5 mm, maybe that is why it flipped out over the edge. Anyway, how can I check if pressure is too high in engine? A friend recommended me to take off the oil filling cap and check if its puffing. Is there a better way?

 

Your piston rings could be worn to the point of letting boost into the crankcase. Do a compression test on all cylinders and see what your numbers at at.

 

With the PCV valve, did it move easily as you shook it? Blow into one end, lets air through, other end stops air?

 

Just curious. Why would you want to bypass the filter?

 

Factory fuel filters cost $75+ a piece and are a pain to replace often, even though Subaru says you should never replace them (naive pipe dream), especially with ethanol in gas. Ethanol absorbs water, then that watery ethanol mixture gets trapped in a traditional fuel filter and water destroys the paper element.

 

With that in mind, with our clean US gas you should probably replace the fuel filter every 3-5 years. In other countries every year could be required.

2005+ Legacy's have an inktank fuel filter, and not the easy to replace ones like WRX's and STI's had in 2005-2007, don't worry 2008+ WRX's followed the Legacy's painful setup too.

 

Replacement fuel filters cost $75+ and take a lot of work to remove and replace. For this reason I stared looking for a cost effective and maintenance friendly setup.

 

Item list:

1 x $12 - 10" to 14" Plastic Corrugated Fuel Flex Hose, can get them at Auto Performance Engineering.

1 x $1 - 11.3mm Oetiker Clamp (Clamping range 9.6mm-11.3mm)

1 x $1 - 14mm Oetiker clamp (Clamping range 11.5-14.0mm)

1 x $10 - Engine bay fuel filter from WRX/FXT

1 x $8 - 5/16" Fuel injection hose

1 x $6-$20 - Pliers for Oetiker clamp (I used Click-R Type Pliers)

Total = $32 without pliers, next years fuel filter replacement $10...

 

It's always a good idea to buy a spare parts (I bought 3 hoses in different sizes and tested fitment with them all).

 

Exploded view of the fuel pump assembly

http://legacygt.com/forums/attachment.php?attachmentid=258360&stc=1&d=1510889111

 

Fuel pump and filter without the tub

http://legacygt.com/forums/attachment.php?attachmentid=258355&stc=1&d=1510889111

 

Fuel filter is inside of this plastic

http://legacygt.com/forums/attachment.php?attachmentid=258356&stc=1&d=1510889111

 

I was trying to gracefully remove the plastic, but it didn't budge and had to be cut off. This fuel filter is from a car with 30k miles, look how dirty it is still.

http://legacygt.com/forums/attachment.php?attachmentid=258357&stc=1&d=1510889111

 

Before I found out about the wonderful corrugated plastic hoses, I was gonna use submersible fuel injection hose ($20 a foot!). I drilled out the hole to accommodate for that hose. You will need to drill the hole out a bit to fit the corrugated plastic, but not this much.

http://legacygt.com/forums/attachment.php?attachmentid=258358&stc=1&d=1510889111

 

Original idea was to use the 5/16" submersible fuel hose and attach it to the stock corrugated plastic hose. But I couldn't find a reliable way to clamp it on (no barbs on stock plastic end).

http://legacygt.com/forums/attachment.php?attachmentid=258359&stc=1&d=1510889111

 

When I decided to just remove the stock fuel hose, I found that our fuel pumps are 5/16", but the nipple on top is actually 3/8".

http://legacygt.com/forums/attachment.php?attachmentid=258361&stc=1&d=1510889111

 

I spent weeks looking for something that could work, even bought 3" of the submersible 3/8" hose. In the end, I used the connector from the factory corrugated plastic hose and heat gun to expand the 5/16" hose to be 3/8", Don't heat the flex joints!

http://legacygt.com/forums/attachment.php?attachmentid=258362&stc=1&d=1510889111

 

Fuel pump end is 5/16", I dipped the hose into hot water to soften it enough to be able to slide it onto the pump easier. Once again don't heat the flex joints.

http://legacygt.com/forums/attachment.php?attachmentid=258363&stc=1&d=1510889111

 

Had to cut the filter assembly a little more to clear the Oetiker clamp, after that fit perfectly

http://legacygt.com/forums/attachment.php?attachmentid=258364&stc=1&d=1510889111

 

Update: Heatshrink the hose on this part and use an Oetiker clamp, regular fuel injection clamp didn't hold the fuel pressure.

http://legacygt.com/forums/attachment.php?attachmentid=258371&stc=1&d=1510889111

http://legacygt.com/forums/attachment.php?attachmentid=258372&stc=1&d=1510889111

http://legacygt.com/forums/attachment.php?attachmentid=258373&stc=1&d=1510889111

 

Looks confusing eh?

http://legacygt.com/forums/attachment.php?attachmentid=258365&stc=1&d=1510889111

 

The return drain hooks right back up no problem.

http://legacygt.com/forums/attachment.php?attachmentid=258366&stc=1&d=1510889111

 

The fuel hose needs to fall in between the plastic bends or it wont clear the bucket, this is why a 12"+ hose is needed.

http://legacygt.com/forums/attachment.php?attachmentid=258367&stc=1&d=1510889111

 

 

There needs to be space between the top and the hose, because the assembly compresses when you install it. This is where 15" hose was getting a little long, luckily I found space to move it around and not hit the roof.

http://legacygt.com/forums/attachment.php?attachmentid=258369&stc=1&d=1510889111

 

Update: I switched to use Oetiker clamp, don't use fuel injection clamp it wont hold the fuel pressure.

http://legacygt.com/forums/attachment.php?attachmentid=258370&stc=1&d=1510889111

 

Finally all together and somewhat fitting well

http://legacygt.com/forums/attachment.php?attachmentid=258368&stc=1&d=1510889111

Edited November 17, 2017 by covertrussian

Now that I finally finished the fuel tank filter bypass and since I already have the engine bay fuel filter, I can finally install the new assembly.

 

Pulled the rear lower cushion out, it was a mess, took a shop vacuum to it.

http://legacygt.com/forums/attachment.php?attachmentid=258381&stc=1&d=1510889763

 

There are two black doors, fuel pump is on the passenger side.

http://legacygt.com/forums/attachment.php?attachmentid=258388&stc=1&d=1510889828

 

Looks like mice have been busy, used the shop vacuum to clean it out too. This is actually important because all of that crap will fall into your fuel tank!

http://legacygt.com/forums/attachment.php?attachmentid=258382&stc=1&d=1510889828

 

Pull the fuel pump fuse and idle the car till she dies, this should get rid of most of the fuel in the fuel lines. It is not sufficient to just unplug the fuel pump plug! I did that and the car kept on idling still (but struggling), plus threw a CEL.

 

It is much wiser to do this install on 1/2 or less full tank. I just got back from a highway trip and wanted to replace the pump before another road trip. I drove 25 some miles (should have been 1 gallon used) and it still was way too full, lets just say my driveway got a ton of gas on it...

http://legacygt.com/forums/attachment.php?attachmentid=258383&stc=1&d=1510889828

 

Stock fuel pump assembly in it's glory, it looks pretty clean not yellow like a lot of them tend to be. I wonder if it was replaced anytime recently.

http://legacygt.com/forums/attachment.php?attachmentid=258384&stc=1&d=1510889828

 

Modified assembly ready to be installed. The rubber gasket has nipples and the spacing varies, thus it only installs one way to the metal bracket. For this reason it's a good idea to attach the rubber gasket and metal bracket before you try to stick it in the fuel tank.

http://legacygt.com/forums/attachment.php?attachmentid=258385&stc=1&d=1510889828

http://legacygt.com/forums/attachment.php?attachmentid=258386&stc=1&d=1510889828

 

After some fighting finally got her in and tightened and hoses plugged up

http://legacygt.com/forums/attachment.php?attachmentid=258387&stc=1&d=1510889828

 

I started and idled the car for a good 20 minutes to make sure it was happy, fuel pressures seemed in order too. Went for a drive watching the wideband making sure it wasn't leaning out, after that gunned it a ton and took her on a 15mile highway trip, all went flawless. I'm keeping the stock fuel pump assembly in the car just in case still though .

 

Learning views are still looking the same so far, will drive for a while and will see if they change. AFR's were about the same too, which means the previous filter was not too clogged, which is a good thing. Guess will see if it was clogged enough to hurt my gas mileage though.

Edited November 17, 2017 by covertrussian

For whatever reason i thought the flat mesh on the bottom of the assembly was the filter. It's actually just a "rock screen" though.

 

Part number and install of wrx/fxt filter? I assume/hope it's in the engine bay (or at least easy to access).

 

Might do this after fixing/reducing my stumble, but will be hard because i am about to purchase an unmodified housing to replace my modified one, only to modify it again...

 

And doubly hard after spending a few hundred to hopefully fix the stumble. Good thing this is "cheap"!

 

EDIT: FXT/WRX engine bay fuel filter part number - 42072PA010 - $25 (recording here for my own benefit)

 

Sent from my XT1028

Edited March 23, 2015 by Flinkly

For whatever reason i thought the flat mesh on the bottom of the assembly was the filter. It's actually just a "rock screen" though.

 

That's been the thought on this forum for a while, because Subaru said there is no replacement cycle for the fuel filter people assumed it's not there. The flat mesh is only good for huge particles, for smaller stuff you still need a fuel filter to avoid clogging up your injector meshes.

 

Part number and install of wrx/fxt filter? I assume/hope it's in the engine bay (or at least easy to access).

 

I just got it from Advance auto, nothing special. I might actually use a 300zx fuel filter next time. I stock a few at home because I run them on my Nissans.

 

Currently I have this:

http://i160.photobucket.com/albums/t188/covertrussian/Cars/05%20LGT/Engine/Fueling/FP%20Gauge/FPGauge_006.jpg~original

 

Might do this after fixing/reducing my stumble, but will be hard because i am about to purchase an unmodified housing to replace my modified one, only to modify it again...

 

And doubly hard after spending a few hundred to hopefully fix the stumble. Good thing this is "cheap"!

 

Sent from my XT1028

 

This could fix the stumbles indeed, I haven't experienced them thus can't say if it helped . How badly hacked up is your current assembly? Even if your housing is badly hacked up you could still do what I did, the only reason you need the housing is to hold the fuel pump in place and that's it.

Fixing the stumble with new regulator, and replacing the whinebro i modified my housing for to try stock and then a dw65c. I might try all combinations to see what happens to the stumble, but all with dw850 injectors.

 

Sent from my XT1028

I think you should be able to use your current housing, heck I had to drill it out and break some stuff to get the clamps to fit. I as always hit the 20 image limit per post so had to omit some pictures.

 

This is already drilled out for 5/16" fuel injection hose:

http://legacygt.com/forums/attachment.php?attachmentid=258389&stc=1&d=1510890244

http://legacygt.com/forums/attachment.php?attachmentid=258390&stc=1&d=1510890244

 

Another reason I went with Oetiker clamps is they are the lowest profile out of all all other options:

http://legacygt.com/forums/attachment.php?attachmentid=258391&stc=1&d=1510890244

http://legacygt.com/forums/attachment.php?attachmentid=258393&stc=1&d=1510890244

http://legacygt.com/forums/attachment.php?attachmentid=258392&stc=1&d=1510890244

Edited November 17, 2017 by covertrussian

Your piston rings could be worn to the point of letting boost into the crankcase. Do a compression test on all cylinders and see what your numbers at at.

 

With the PCV valve, did it move easily as you shook it? Blow into one end, lets air through, other end stops air?

 

I changed for a brand new engine 12.000 miles ago so the rings are hopefully not worn. Have long thought of doing a compression test, main problem is that its so tricky to get to the inner holes.

PCV valve seems to work well when blowing gently and also sucking.

When do you have the highest pressure, its it at low rpm with high load or high rpm?

I would say the highest pressure will only come with high RPM, load could have an effect though too, higher load = PCV valve is closed thus no suction from intake manifold.

Do you suppose you could use a couple of wraps of lockwire in place of the otiker clamp and have less fitment issues?

I drilled the hole out back when I was gonna use a rubber fuel hose and was planning on using the fuel injection clamps. Next one I do (hopefully not anytime soon), I will do much less drilling.

 

Even after I decided to go with corrugated fuel hose I was still running into fuel clamp issues and fitment, Oetiker clamps are actually a blessing, they are super low profile. I would not trust wire wraps or lock wire, or even worm clamps for anything fuel related. All can pop off under pressure.

Just got back from a 400 mile trip, was a little hesitant taking the Legacy after such a major mod, but my other car wasn't ready to haul a transmission and bunch of car parts.

 

I did run into an issue, looks like my fuel pressure drains instantly after fuel pump is primed or car is turned off. I'll need to do some testing, maybe the fuel injection clamp is not holding afterall (will probably switch to oetikers and heat shrink the tube more). But it could also be my FPR failing. Either way here are some gas mileage numbers:

 

Going there I had to fight with traffic and go 75mph, got 25.68mpg, ambient 45-60F, not that great for going "downhill" (taking 81 north from VA to PA, terrain 1300ft-400ft) and this is with a bunch of heavy car parts that I was selling.

 

Returning I had a hard time finding a Shell gas station, luckily found on in PA right before MD. Terrain was 500ft-1300ft on 81 south, a lot less traffic, ambient 43-48F, going 70mph got 31.19mpg! I might have to do a more controlled run to neighboring cities to see if these numbers are replicatable, if they are my stock fuel filter was getting clogged.

Edited March 23, 2015 by covertrussian

Ordered oetiker clamps to replace the fuel injection clamp, they were supposed to arrive on Friday but USPS delivered it to the wrong mailbox and I never got it... But with the warm weather I had some motivation to troubleshoot the fuel draining too quickly. I tried to drain a bunch of fuel from the tank preparing the car for when new clamps would arrive this week, I disconnected the feed hose and stuck it in a gas can and primed the fuel pump a bunch of times. About 2 gallons in the can I noticed that fuel was still coming out of the fuel rail. Disconnected the return hose, primed pump and saw fuel coming out of both hoses, but more out of the feed hose, looks like there is a bunch of crosstalk between the feed and return hoses...

 

Figured 2 gallons was enough, but I was very wrong, once again lost a ton of fuel to the parking lot. Had a friend prime the fuel pump while I had the fuel pump kind of removed, saw that the fuel was indeed coming out of the 3/8" connection with a fuel injection hose clamp.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/05%20LGT/Engine/Fueling/Fuel%20Filter/SAM_7491.jpg~original

 

Remembered that Home Depot sells "SharkBite" oetiker clamps for pex pipes, 3/8" (says 13.3mm on it) seems to fit. It was a little tight squeeze but it fit. In this pic you can see the lip of the fuel hose is misshaped and why it's leaking.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/05%20LGT/Engine/Fueling/Fuel%20Filter/SAM_7513.jpg~original

 

Used a heat gun to heat it up and get it to fit better on the nipple. One of the issues with nipple is it's multi-ribbed for no ones pleasure, there is no flat surface for the clamps to make a good seal against! I'm hoping the heat will cause the hose to conform to the ribs and clamp will keep it form moving.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/05%20LGT/Engine/Fueling/Fuel%20Filter/SAM_7514.jpg~original

 

Oetiker clamp installed and crimped on while hose is still warm, it crimps it so well the fuel hose would not twist at all, this inspired confidence .

http://i160.photobucket.com/albums/t188/covertrussian/Cars/05%20LGT/Engine/Fueling/Fuel%20Filter/SAM_7515.jpg~original

 

Got it installed, car idled perfectly, and maintained pressure after car was turned off. Went for a drive and seemed to do drive well. Turned off the car for an hour and it was still at 35psi, so far looks good. Will give it a few days before I say it's fixed, since the fuel hose could expand still.

It's holding pressure much better so far! It drained about 10-15psi in 4 hours, which I think is about what it was when I was on the stock filter assembly.

 

I really should have timed it before... anyone with a fuel pressure gauge wanna check the pressures on 4 hour intervals for me?

I love this thread, thanks so much CR for detailing/presenting all of this.

Since EJ255's have plastic intake manifolds Subaru decided to use rubber o-rings for sealing the manifold to TGV's (probably because plastic manifold can't be torqued to same specs as aluminum with metal gaskets). After 10 years rubber will dry out and compress, which can lead to boost leaks. My learning views constantly would show +5 to +10 in 0-<5.60 Airflow ranges, which a lot of people mentioned could be a boost leak.

 

Intake Manifold Gaskets Part Number: 14035AA492

You will need 4, they should run you up about $20.

 

I replaced them by leaving the intake manifold on and just propping it up with a big screw driver.

 

1

The 18whp/34wtq gain is amazing, but I wont get too excited until I can replicate it a few times. Second run was 5*F warmer (based on Accuweather which is what I use for temp/pressures). Looking at the log, IAT was higher by 2*F on second run, so that should have hurt performance. Both runs had 1 IAM, but second run had much more timing, 10* more on average, which explains the power gains!

 

Update: Did another run (10 miles after ecu reset), this one at 73*F, power is back to normal, but torque stayed up. Reading STI forums it seems like it's common for these cars to make more power on fresh ecu reset, and with time ECU pulls back timing due to knock/false knock.

 

What probably happened is, with the boost leak, wastegate would be closed longer to maintain the target PSI, which would cause the turbo to overspin/go outside of it's efficiency. When the turbo is outside of it's efficiency map it just blows hot air, which causes timing to be retarded due to knock. I will drive around and see if my learning view for A range is still high.

 

Just popping it off seems like not too bad of a job, how long did that take you with that technique?

Edited May 28, 2015 by ObiWanToby

I would say took about an hour or two. It was a pita but not impossible.

until looking back at those older posts, I never knew your car was red. I knew your profile pic wasn't the LGT, but for some reason assumed the LGT was black as well. lol.

I guess I don't post too many pictures of the Legacy exterior, even though she's gorgeous, I just don't wash her enough and weather hasn't been good till lately.

 

Profile pic is of my turbo +6 Speed Infiniti G20, the car that still has my heart (I recently rebuilt her from almost selling her).

This is an amazing thread! Makes me jealous I don't have a place to make real progress on my project.

 

On the bright side, I get to pay inept shops to do the work I need. Perhaps everyone else should be the jealous one.

Will probably take me two hours then. Everything little I do always ends up with complications. the 6 hour brake job from hell was the last struggle (sheared a bolt).

 

Definitely probably have a vacuum leak, figured those o-rings are shot. Was there enough room to keep the intercooler on or did that come off?

Edited May 28, 2015 by ObiWanToby