I am Leaking Gas when I fill up

GMAN

GMAN

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My 93 is leaking gas. When I fill up, I can look under the car it is leaking. Then I smell gas all throuout the inside of the car. I need to get this fixed. Any suggestions?
 
Follow the leak. Probably on top the tank somewhere so you'll have to drop the tank to find it if so.

My wifes old 92 T-Bird started leaking, couldn't see where...dropped the tank and it was a fuel line that ran up onto the top of the tank. It was rubbing on the body/frame right where it turns up to go up to the tank top. Repaired it and was fine.

Same chassis so maybe similar problem.

Sometimes the senders rust out too. Happened on my Mark7.
 
I haven't dropped the the tank yet. I just filled it up today. I will run out the gas and try next weekend. How hard is it to drop the tank?
 
Usually the do not leak unless the tank has been dropped and the fuel tank oring was not greased and stretched properly.....they shrink up as soon as they hit the air almost always.

For me it was not that big of a deal....you do not have to remove the exhaust, but simply drop it from the rear hangers so you can get the tank out.

Here is a step by step procedure to drop the tank with tools involved.
 
shrink?

never dropped a tank out of 1 of these but every single car ive dropped a tank on (100s) the o-ring expands from the constant exposure to fuel. never had 1 contract after any amount of time in the air upon removal.
 
I have dropped the tank on these cars about 50 times and have removed the fuel pumps, and they shrink on these. They do not touch fuel in any way shape or form. I have had to stretch them over half of the time because the sit in a sealed casing when the fuel pump/housing are in place and have not been removed since the car was built. Once that happens and air gets into the oring seal it out gasses and shrinks. Also has to do with the heat generated and it wants to shrink the whole time its in there and once it is removed it will want to shrink. The orings on these tanks never touch fuel, if they sit in fuel they will expand once removed due to the infiltration of the fuel into the pores of the oring.
 
I'm thinking if I drop the tank to check the oring, should I go ahead and replace the fuel pump? I am getting a Check Engine light, which came back to Bank1 Lean.
 
I would say yeah go ahead......why hafta drop it a second time......

what was the code you got for bank 1 lean....might not necessarily be the fuel pump.....
 
bank 1 lean wont be FP. most likely your looking at an intake leak of sorts.
 
id start by tracing the leak, gas leaves a white trail when it drys, so id look under it for a trail, before you drop the tank
 
I dont remember the exact code, but that particular phrase I do remember "Bank 1 Lean." I believe it was a 3 something code. But be that as it may, I am spilling fuel all over the ground after I fill up. Can't hurt to change the fuel pump after 14 years. What kind of fuel pump should I go with?
 
Well, depending on the code it could be a O2 sensor going bad as well. I looked up different codes for someone else and one of the fixes was to replace the O2 sensor(s).

As for the fuel pump I am running the Walbro 255 LPH HP fuel pump. I got it here it is the 96-97 Cobra unit, and I think the model number was GSS342. Now, the only bad thing about running that fuel pump is that you will also need to replace the pressure regulator. You do not necessarily hafta replace it right away, but you will eventually due to the higher pressure will destroy the factory diaphragm inside the factory fuel pressure regulator. And the regulator that I have/use is this unit. Now that regulator is good for Mark VIII's from 94-98, however if you have a 93 then this unit is the correct one. The mounting flange for the 93 is the same as the Mustangs of that year only for the 93 Mark VIII.
 
I thought about going high performance, but I am thinking of keeping it stock. I noticed the price for the Walbro fuel pumps are considerably less than what I found at O'Reilly's and Autozone. The picture looks different than the OEM. Is there a special way to install it?
 
You are WAY better off with using a performance unit. If you are in there spend the extra couple of snappers for the upgraded performance unit. If you EVER plan or have any performance mods done to the car you will need the extra fuel. And, if I remember correctly the performance unit is cheaper/better than the stock unit.

As for the installation there is no special things needed....I even have posted on here step-by-step procedures on what you need to do not only to drop the tank, but to replace the fuel pump.....with pix even.

Here are the pix.
 
My daughter's 02 Mustang had a gas leak. Found it to be the fill tube. It had a nice size rusted hole in it about .25".

My 88 T-Bird also had a leak it too was the fill tube also.

Fuel pump is easy to install. I used Ray's instructions also... it was 15 degrees out when I had to crawl under my 93 to drop the tank and replace the fuel pump.
 
bank 1 lean would be p0171.

another possible is p0455. gross evap leak.
 
My fittings that connect the fuel filter on my Mark VIII started leaking once. The o-rings were shot and it was losing fuel under pressure. I had to replace the fuel line behind the wheel well that connects under the car to the metal lines.
 
This is just an observation, but it seems that after I changed my fuel filter, she's running better. There's no hesitation when I first start her up. She takes off down the road, and I've seen no check engine lights. I am going to do the seafoam next and see how that helps. I am wondering now could the old fuel filter been clogged? Would that have caused poor engine performance?
 
Ahhhhh....yes in a heartbeat it would.

Oh, one other thing, if you decide to get that fuel pump and regulator you will also need the fuel gauge for the schrader valve so you can adjust the fuel pressure to 40 psi with the vacuum hose removed......:D
 
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1wykdmk8 said:
Ahhhhh....yes in a heartbeat it would.

Oh, one other thing, if you decide to get that fuel pump and regulator you will also need the fuel gauge for the schrader valve so you can adjust the fuel pressure to 40 psi with the vacuum hose removed......:D
Click to expand...

I am going to go ahead and get the fuel pump and regulator. It couldn't hurt. What do you mean about the fuel gage for the shrader valve? What does that do? Do you have any pics and how to's?
 
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Here is a pic of what I was talking about. All you gotta do is remove the lil plastic cap off of the schrader valve and attach the gauge the way it is specified in the kit. And the pic I have attached is what it looks like on the car....it is on drillers car.....

driller.jpg
 
Well I finally finished the fuel pump. When I got it down, I had other problems. The oring was cracked and I needed another one. So off to the junkyard I went looking for an oring for the sending unit. No luck. I ended measuring the diameter of the old oring and going to a local seal company and getting a suitable replacement. It worked like a charm. So I am back in business. Like others have said, changing the fuel pump is a royal P.I.T.A:mad:. By far the hardest project I've done.

I got the new fuel pressure regulator installed, and chipped an oring on an injector and sprayed gas everywhere. Back to the seal company for another oring. After that was done, I took of the schrader valve and put in an adapter and then installed the fuel pressure gauge. Now I am looking like Driller now. :D

005.jpg


007.jpg


008.jpg
 
nice, does it run any better now? Oh btw ive done the fuel pump not tooo bad. My toughest job to date has been that stupid egr tube.... Right now I am puting a trans in my mark and I think this is gonna beat the EGR tube for biggest PITA every single bolt on my car is frozen... broke 3 of the 4 bolts that hold the exhaust to the manifolds....
 
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