Gas Leak

JamieR · #1 12-06-2008, 07:30 PM

I have a 1989 V6 3.0L 4Runner. I am away from it and I miss it a lot. My Dad is watching it for me. He just told me I am leaking Gasoline from the front right side somewhere. It's coming out from the frame behind the right front wheel somewhere but not sure where the source is or how it's getting in the closed frame.... If you run it for a while then take the gas cap off you can hear it suck air as if it was empty. It takes some time before it starts to leak but once it starts it pours out. When I turn it off and then unscrew the cap it stops and does not leak at all. As it should I guess if you take the pressure off the tank.

Can anyone give me some insight of where or what could be causing this?

I just had a new fuel guage put in the tank and the fuel pump has been reconditioned as well. All the lines under the tank have been redone since I had the tank off. Could there be an old hose there somewhere that has rotted and now leaking?

Brian R. · #2 12-07-2008, 07:17 PM

A known problem with that engine is a leaking fuel line pulse damper.

JamieR · #3 12-09-2008, 03:50 AM

What exactly is a fuel line pulse damper? What does it do and where is it located? Thanks

Brian R. · #4 12-09-2008, 05:27 PM

It's in the fuel line between the filter and the injectors - near the firewall.

Its purpose is to smooth out the pulses of high pressure from the fuel pump to give a more consistent flow of fuel to the injectors.

fourwd1 · #5 12-11-2008, 12:11 PM

Quote:

Originally Posted by JamieR

I have a 1989 V6 3.0L 4Runner. I am away from it and I miss it a lot. My Dad is watching it for me. He just told me I am leaking Gasoline from the front right side somewhere. It's coming out from the frame behind the right front wheel somewhere but not sure where the source is or how it's getting in the closed frame.... If you run it for a while then take the gas cap off you can hear it suck air as if it was empty. It takes some time before it starts to leak but once it starts it pours out. When I turn it off and then unscrew the cap it stops and does not leak at all. As it should I guess if you take the pressure off the tank.

Can anyone give me some insight of where or what could be causing this?

I just had a new fuel guage put in the tank and the fuel pump has been reconditioned as well. All the lines under the tank have been redone since I had the tank off. Could there be an old hose there somewhere that has rotted and now leaking?

That's exactly where the evap canister is, and it's breather hose actually goes into the frame. The evap canister collects fumes from the gas tank and other places.

If the tank hoses were reconnected incorrectly after the tank work or are crimped or clogged, you can get all the symptoms you describe.

JamieR · #6 12-13-2008, 04:09 AM

I took the truck back to the mechanic and as it turns out it seemed he did swap the hoses saying that in every other vehicle he has ever worked with regarding fuel tanks if the hoses were put in wrong the vehicle would not run at all and can't figure how he never noticed it before as they had my 4Runner for quite a while. So it looks as if the problem has been solved but will keep my eye on it anyway.

Thanks for all the help guys, much appreciated

Brian R. · #7 12-13-2008, 12:05 PM

So at what point in the system was the gas leak? Was there a disconnected or damaged hose?

fourwd1 · #8 12-15-2008, 08:23 AM

When the hoses are connected wrong at the tank (or if one is crimped or clogged), you can get a condition where gas is "pumped" up to the evap can instead of fumes. The evap can floods, and it's discharge hose goes into the frame, hence his case where the gas was leaking from the frame at the front right wheel.

JamieR · #9 12-15-2008, 01:14 PM

Quote:

Originally Posted by fourwd1

When the hoses are connected wrong at the tank (or if one is crimped or clogged), you can get a condition where gas is "pumped" up to the evap can instead of fumes. The evap can floods, and it's discharge hose goes into the frame, hence his case where the gas was leaking from the frame at the front right wheel.

Yeah in my case the hoses were put in the wrong way. But then how big is the evap can? How much fuel would have to go in there before it starts to overflow?? As my Dad said that only sometimes would it pour out and other times it would not. If it did not overflow on a short drive would the fuel just stay in the evap can until the next time or would it just slowly flow out over time? It is only driven periodically and keeping it stored until I return. Is there any damage long term that could have happened with this? I did have a bit of a gas smell (like fumes) every once in a while ever since I bought it, and my mechanic said he did put slightly longer hoses to the can.... would this fix the gas smell maybe?

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