2G Fuel smell

[sinned4g63]

I've been noticing in the past few months of driving that it starts to smell like fuel after I park, usually I notice when I get home after work (about 20-30 minute drive). When I park I walk around the back of the car and away from the passenger side and that's usually where I get the most noticeable smell. I checked under the car and to little surprise found some rusty lines that appear to be brake and fuel.. one showing spots of rust that I assume is the fuel line hence the smell. It never drips and I never see any puddles but it's there. Along the process of refreshing the car I'd like to do steel braided lines anyways but I'm not sure where to find this portion. I found stock lines on mitsubishipartswarehouse.com p/n MR134402 for large and MF661023 for small but having some difficulty finding aftermarket lines.. I have a mechanic friend that has a spray for recoating the underside of cars but he shared the concern of trapping moisture and possible debris so again turning to the steel braided option. Can anyone recommend a kit from extremepsi.com or elsewhere or is it simply just replacing the line? Any insight appreciated

 

[lasershark]

Have you taken the back seat out and open up the fuel pump access plate? Check the lines coming in and out of the fuel pump hanger and also see if fuel is pooling up on top of the fuel pump assembly. Open it up and pressurize the the fuel pump and take a look.

 

[motomattx]

There was an issue on some of the 2g's with fuel vapor leaks, I think there was even a bulletin on it, if I recall it was the seal under the back seat for one of the senders would get deformed and let vapor leak out, mine did it.

 

[TuJay]

Check what he said ^^

Also have you checked your catalytic converter? A faulty one can defiantly make that smell especially if you're running rich so check o2 sensors also. My GST is straight piped and runs rich and the exhaust smells almost exactly like gas.

 

[Murdertalon]

I would take your back seat out, 4 screws remove the fuel pump access panel on the passenger side and inspect for any wet spots, if you smell strong gas there you have at very least a vapor leak and this is something to take seriously. The seal for the fuel pump to tank must be installed to the tank before you put the pump in place or it can pop out of place and leak. I found this out from working on my fuel pump quite a bit.

 

[PlanZero]

Good to know. I was having this issue sporadically on my 96 but it went away on its own. I thought it was the fuel pump/tank seal (the big rubber washer) since it felt old when I changed my FP a couple years ago. I have a new one but haven't changed it yet. It was always hard to figure out since I swore I smelled it both outside and inside the car after I shut her off in the garage.
So what seal is it specifically?

 

[Murdertalon]

Well there is just the large rubber seal that the fuel pump hanger drops into and then the plastic lock ring screws onto the tank holding the assembly together. If that rubber seal isn't set just right it can leak fumes or fuel. Like I said just make sure if you pull the hanger you install the rubber seal into the tank then drop the hanger into that. I thought it was supposed to go on the hanger then drop the hanger in place, but then I noticed it sometimes doesn't sit right if you do that.

If you have fuel leaking from any of the lines back there that should be pretty easy to identify. If you take it apart again use some anti seize on the an fittings or fuel rated pipe dope. ACE sells some decent fuel rated pipe dope.

One other thing to look at I had that lock ring thread on at an angle once and it had a gap on the front or back (cant remember) but I could visually see that it didn't seat properly.

 

[PlanZero]

I hate that ring on an awd. A fwd has a bunch of 10mm nuts instead but Idk what the torque spec is. I get all paranoid when tightening light stuff like this, the trans pan gasket or vc gasket since my car shakes so much she loosens bolts and sometimes it's not practical to loctite all of them.
But I digress, OP is the pump aftermarket? If so those connections would be the first place to check. Especially where the hard line on top of the pump assy goes under the seat where most people cut the metal to get the pump and line out. Ive seen people be extremely rough in attempting to pullout the stock fp assembly and still reuse the hard line.
While you're in there throw in an Evo X fuel pump. You have to modify it slightly but well worth the $40 you can usually find em for

Actually I just looked at OPs pic. Thats probably nothing and most likely isn't your problem. Check the filler neck and gas cap. Check under the back seat as stated (I also use some new weatherstrip along the edges of the FP access panel) and if your emissions charcoal canister was deleted make sure the tank vent line terminates somewhere safely.

 

[Mauispyder]

Do you still have your charcoal canister? Bad check valves can cause it to smell like gas.

 

[sinned4g63]

So I've been driving around for the past week but in colder weather (towards 30 at night and 50 during a warm day) so I haven't smelled anything strong as far as fuel goes. Took it for a drive about an hour on Sunday when it was warmer and still nothing too profound. Today I did end up checking the cover under the passenger back seat cause we were slow at work and everything looks and feels dry but when I took the cover off I immediately got a strong fuel smell. There wasn't a lot of light because it's cloudy at the moment and I'm at work but it is definitely stronger with the cover off then it ever has been walking around the car or outside or underneath by the fuel line. Everything in the fuel system is stock in reference to the charcoal canister, so it should still be there I assume. I did also notice when taking the cover off one of the corners was bent up as if someone has already been poking around.. I'll have to take a better look with some light around the gasket.

 

[Murdertalon]

LPT: I always carry my smart phone with me, thus I always have a flashlight on hand.

fuel smell from the top of the tank could indicate fumes leaking or actual fuel either way that's bad. you have some sort of sealing issue seems like some people on the forums know about leaking gasket being a known issue.

do you have a bolt to tank style or have a lock ring style? I am figuring lock ring if it's passenger side. you can take the lock ring off and inspect the seal, or just tighten the lock ring a little. be rather careful not to twist hard lines.

 

[sinned4g63]

So finally having a nice day and a day off I was able to go out and find something related to the fuel smell. As soon as I parked I jumped out to look at things and here's what I saw looking at the pump under the panel towards the front of the car. This may be out of my driveway expertise.. any thoughts?

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[sinned4g63]

do you have a bolt to tank style or have a lock ring style? I am figuring lock ring if it's passenger side. you can take the lock ring off and inspect the seal, or just tighten the lock

Looks like bolt to tank, sorry for the delay.

 

[Murdertalon]

Is that wet/fuel on the lines or just a shiny spot? wipe it with a finger and you will be able to smell if its gas or just water from the road.

 

[sinned4g63]

Well I wasn' able to get my hand in there too well.. the one spot I was able to feel just felt smooth, oily if anything but didn't leave much of a residue or smell on my fingers. If it was fuel I couldn't tell. Seeing as how it's not a lock ring would it still be as easy to check the fuel pump seal? Still not seeing any puddles or residue on top, mainly concerned about the metal lines but might as well cover everything.

 

[PlanZero]

Hard to tell from the pic. The gasket on a FWD is under the bolts holding the ring on, I dont have the part number but they're like $3. If your 20 year old car still has the stock fuel pump consider yourself lucky and just upgrade it now.

 

[sinned4g63]

Hard to tell from the pic. The gasket on a FWD is under the bolts holding the ring on, I dont have the part number but they're like $3. If your 20 year old car still has the stock fuel pump consider yourself lucky and just upgrade it now.

Was gonna be my next topic one of those "while I'm in there" scenarios. Still any input on the steel lines underneath? No ones mentioned them at all. XD not sure if it' something to be concerned about.

 

[PlanZero]

Feel the lines to see if they're wet. They have a glossy paint/coating that can appear wet. I highly doubt your lines are an issue unless theyve been messed with before. Awhile back I was researching my own mystery fuel smell after shut down and it's a fairly common problem, though the solutions are not.

 

[sinned4g63]

Feel the lines to see if they're wet. They have a glossy paint/coating that can appear wet. I highly doubt your lines are an issue unless theyve been messed with before.

The part I was able to touch you see in the picture feels dry, but what about the bottom in the first picture where the coating is off and it's starting to corrode?

 

[PlanZero]

Well I can only tell so much from a pic but it looks like surface corrosion. Clean it with a wire brush then examine it after a ride. Spray with rustoleum. I've seen much worse and still wasn't eating through to the point of leakage.

 

[sinned4g63]

Well I can only tell so much from a pic but it looks like surface corrosion. Clean it with a wire brush then examine it after a ride. Spray with rustoleum. I've seen much worse and still wasn't eating through to the point of leakage.

Awesome, I will do that. In the meantime fuel pumps are pretty cheap so once I have one ordered I'll try to update with a pic/findings when I take everything apart. At the moment on extremePSI they have 2 kits for the Walbro 255, one normal for $95, and one "high pressure" for $85.. seems like a no brainer to go with the price but would it be overkill for a stock setup?

 

[PlanZero]

Some people override the stock fuel system with a 255, though a 190 may not be enough if you want to go bigger down the line. I prefer the Evo X OEM pump, usually found for about $40 used or you may find a deal on rock auto. I never ran rich on stock injectors. It only involves a very minor modification to fit. Evo 9 pumps are plug n play but flow closer to the 190. Do the rewire mod on any pump, even your current stocker, for consistent voltage. I pieced together my own "kit" for under $20.

 

[sinned4g63]

Well I meant between the normal 255 and the "high pressure" 255, I found on Auto Performance Engineering a chart showing the difference in gallons per hour to amperage when the fuel pump is working. I guess what I'm asking is, wouldn't the high pressure pump be ideal regardless? I mean aside from the price being cheaper at the moment it just looks like it operates more efficiently. Being new to fuel systems, I'm sure there's more depth then that though. Also for consideration, any idea what the part# for the evoX pump is and what all did you need with your kit?

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[Murdertalon]

The research I have looked at the aeromotive fuel pump is a stronger/better flow under lower psi at rail.

http://realstreetperformance.com/Fuel-Pump-Comparison-Test.html

Lots of people run the walbro255 so I am sure you would be fine running that. All I did was a rewire and bought a autozone special fuel pump comes with lifetime warranty. With a rewire, new pump and new fuel filter its pushing years better than the old setup. I also managed to twist one of my hard lines (main feed) because of a corroded bolt on the hard line to soft like AN-6 setup so I ended up using a weld in an-8 from hanger to an-8 connector and larger soft line to brand new lower an-6 connector.

Be really careful removing those an-6 line connections because once you twist the hard line you have to replace stuff.

Keep in mind if you use a high flow fuel pump you have to also use a fuel pressure regulator, or risk over running the stock one.

 

[PlanZero]

Im too ignorant to give a proper reply as to the differences in 255s. I would suspect the high pressure pump would be the one that may override a stock fpr. Many guys run the normal 255 with supposedly no problem. I got a cheap AEM afpr after I did the rewire, but my adjustments were minimal. There's a bunch of write ups on fuel pump rewire, it involves a relay and fuse and some wire, you can find decent Bosch relays or similar very cheap on eBay and get wire by the foot at HD. Somehow "rewire kits" sell for way more than they're worth