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I can't find the fuel leak.

Posted: Sat Sep 10, 2005 4:48 pm
by vrg3
My new Sport Sedan has a fuel leak. I've smelled it for a few days.

I lifted the car up and saw what looked almost like motor oil on the bottom of the driver side gas tank cover (#10 in the diagram below), and it was actually starting to drop onto the garage floor. I'm guessing that even though the fuel itself was evaporating pretty quickly, it was liquefying some of the undercoating grease and making it look like oil.

So I removed the cover and wiped away all the oily stuff. It looked like it was dripping down from above or something. I let it air out overnight, and in the morning there was barely any fuel smell at all. Then I ran the fuel pump (by going into test mode and leaving the ignition on) and the smell reappeared, right in that area.

I still can't tell where it's leaking from though. The hose connections that I can see (#14, #15, #16) all seem okay, and I don't see any liquid fuel there.

The hose connections at the fuel pump and jet pump are apparently okay. The return line connection at the pump (where it says "c") did seem a little wet -- maybe with fuel or maybe with something else, so I replaced the spring-type clamp with a fuel injection clamp, and it's stayed dry since. I don't think I can access the other ends of these hoses though.

I did loosen some of the nuts on the fuel pump assembly (#1) and when I did, I heard a hissing sound as the vacuum in the tank was released. From this, am I correct in inferring that the leak is unlikely to be in the return or evaporation lines, or in the body of the tank?

Any advice is appreciated... I hope I don't have to remove the tank; it looks like I'd have to remove the rear drivetrain to do that.

http://www.graphics.cornell.edu/~v/pics ... l_tank.png

Posted: Sun Sep 11, 2005 4:30 am
by vrg3
Okay, well, I'm gonna assume for the moment that I'm right that the leak must be in the fuel delivery line. I depressurized the fuel system and am going to leave it overnight. If in the morning I don't smell fuel, I'm gonna take that as confirmation.

If that's the problem, I guess I'm just going to get several feet of that nice cloth-braided fuel injection hose that NAPA sells, and run it from the pump all the way to the pipes under the rear driver side seat (replacing #23, #15, and the pipe in between), ziptieing it wherever convenient.

Any thoughts?

Posted: Sun Sep 11, 2005 4:45 pm
by professor
makes sense just to replace it. sometimes when fuel line gets old the gas just seems to weep through the sides, and you get lots of nice black rubber bits in the fuel.

I find its easier ti fix the problem than to find it in many cases

Posted: Sun Sep 11, 2005 5:52 pm
by azn2nr
you gotta be careful though, fuel will not be dectable by the nose if it supersatruates the air.

Posted: Sun Sep 11, 2005 8:01 pm
by vrg3
professor - Yeah, that's what I was thinking... the only complication is that I don't think these hoses can be replaced without removing the tank. That's why I'm gonna try my idea of running new fuel hose to replace the hard line as well, hopefully without kinking, pinching, or rubbing.

Jason - I don't understand. What does it mean for fuel to supersatruate the air?

Posted: Mon Sep 12, 2005 12:31 am
by azn2nr
i just reread the post but if you have a fuel leak inside the car, wich i see you dont, fuel can supersaturate the air making itself undectable by the nose which then can be ignited at which time bad juju insues.

Posted: Mon Sep 12, 2005 3:45 am
by legacy92ej22t
Wait, what new sport sedan?! :shock:

I feel so left out of the loop, when did you get a new car?

Posted: Mon Sep 12, 2005 4:31 am
by vrg3
Jason - Ah, I see. Thanks for the warning... No, right now it's actually just a very faint smell as I depressurized the system and have been letting it air out. I didn't have any time today to get hose or do any work, so I guess I'll just let it air out longer until I replace the lines.

Matt - Heh... Oh yeah... I bought another car. Don't feel out of the loop... I haven't really said anything about it except for this thread: http://bbs.legacycentral.org/viewtopic.php?t=22938

I have been meaning to take a picture of my two Winestone Pearl 93 Sport Sedans next to each other for a couple of weeks now...

Posted: Wed Sep 14, 2005 12:31 am
by Tleg93
That's cool that you bought another car, congratulations.

It's odd but I've also developed a leak in my 93. It leaves a noticeable puddle behind the passenger side rear wheel. I also noticed that black tarry stuff. In my case the filler tube is bad most likely.

Posted: Wed Sep 14, 2005 12:52 am
by vrg3
Thanks. It's kinda fun having two cars.

I did replace the two lines (delivery and return), and I think the problem has been resolved. There's still kind of a general fuel stink all over the garage and in the car because of all the fuel I spilled, so it's hard to say for certain.

In case anybody's curious, a single 10-foot length of fuel 5/16" injection hose will do you. I think I made one hose a little shorter than 5 feet and one a little longer, since the space to route them is tight. I couldn't get the braided stuff so I just put corrugated tubing over them. I'm not very worried.

Yeah, it's funny... wasn't someone (subyluvr2212 I think) saying how our cars' problems seem to be contagious? After Matt's idling problems on the shootout weekend, my car threw an idle switch code for no reason right before our cruise! Resetting the ECU resolved it...

Given the general area of your leak I agree that the filler tube is the most likely suspect. In this car's case, though, I think the fuel tank was once removed in a collision repair and was removed, stored, or reinstalled carelessly; I can see that the jet pump's fitting on the fuel tank assembly has been bent more downwards than it's supposed to be, for example.

Posted: Wed Sep 14, 2005 1:08 am
by Tleg93
Man, I wish I had a garage. That's where I would like to be spending some time right now.

Thanks for the info. I was going to ask to post a follow up but I knew you would. Majen, teh 91, needs this solution.

Posted: Sun Sep 18, 2005 1:40 am
by Tleg93
Bump

Has anyone on here ever changed the fuel fill tube? If you have, how long did it take you?

Posted: Sun Sep 18, 2005 4:02 am
by Legacy777
It's not too bad. Shouldn't take you more then an hour or so.

Posted: Sun Sep 18, 2005 5:21 am
by vrg3
I haven't done it myself, but it looks pretty straightforward... This parts diagram and these instructions from the FSM make it look easy:

http://www.graphics.cornell.edu/~v/pics ... _lines.png
http://www.graphics.cornell.edu/~v/pics ... ctions.png