LS Swap FJ62 fuel smell problem

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Jan 3, 2018
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I have tried to find help with my issue via reading all the fuel threads but most of the answers revolve around the charcoal canister, which my rig no longer has.

Small rundown of vehicle:
1988 FJ62, 5.3 vortec/ 4l60e swap roughly 7k miles ago. When I swapped the motor I deleted the CC and have vent tube venting into atmosphere inside pass front fender well.

My issue is a really bad fuel smell at pass rear quarter panel (interior) and high pressure at the fuel cap. I have put air pressure into the vent tube and it goes into the fuel tank (duh) but does not seem to vent very well the other direction. I have read that the factory gas cap is not vented so I am guessing that is not the problem. Any insight as where to begin looking is much appreciated.
 

OSS

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You’re smelling gas fumes from gasoline evaporating in the fuel tank.
Just like an open jerry can, if the car fuel tank has a direct unimpeded path to the atmosphere, (no CC or check valve) the gasoline in the tank will continue to evaporate (stinking up the area) until, ultimately, the fuel tank is dry (Given enough time).

If the vapor vent tube you installed near the passenger side is unobstructed, then the tank should breathe easily and no pressure should build up. Since the tank IS pressurizing, there’s a blockage somewhere at the tank for the vapor lines.

The original FJ60 has a vapor separator thingy behind the rear passenger side panel all the way in the back. It’s purpose is to separate liquid gasoline out from the vapor line so liquid gasoline won’t get fed to the front of the car (and ultimately the CC.

My guess is that there’s a blockage somewhere in the vapor line back near the tank. Also remove the right rear panel and inspect the clamps on the vapor separator.
Also check the tubing and clamps under the truck at the very rear hidden under the protective panel near the fuel fill spout.
 
Joined
Jan 3, 2018
Messages
40
Location
Phoenix
You’re smelling gas fumes from gasoline evaporating in the fuel tank.
Just like an open jerry can, if the car fuel tank has a direct unimpeded path to the atmosphere, (no CC or check valve) the gasoline in the tank will continue to evaporate (stinking up the area) until, ultimately, the fuel tank is dry (Given enough time).

If the vapor vent tube you installed near the passenger side is unobstructed, then the tank should breathe easily and no pressure should build up. Since the tank IS pressurizing, there’s a blockage somewhere at the tank for the vapor lines.

The original FJ60 has a vapor separator thingy behind the rear passenger side panel all the way in the back. It’s purpose is to separate liquid gasoline out from the vapor line so liquid gasoline won’t get fed to the front of the car (and ultimately the CC.

My guess is that there’s a blockage somewhere in the vapor line back near the tank. Also remove the right rear panel and inspect the clamps on the vapor separator.
Also check the tubing and clamps under the truck at the very rear hidden under the protective panel near the fuel fill spout.
Thanks for the input, I’ll start checking the lines in the back. I checked that little white valve near the separator but it flows both ways.
 
Joined
Jan 3, 2018
Messages
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Location
Phoenix
put a charcoal canister back in it

I am waiting on one to come in but the problem was at the back of the vehicle. Pulled everything apart this morning and found that the little white check valve at the top of the separator had gone bad and was stuck closed and not letting the air escape through the vent line.

Removed the valve for now and hooked everything back up and no more pressure issues nor fuel smells.
 

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