Air getting into fuel filter

[Aaron]

Hello,
So, I have noticed that I am getting a lot of air in my fuel filter after the jeep has sat for a few hours. I can't find any leaks and I made sure my tank was venting properly. Once the jeep gets running all of the air in the fuel filter is gone and it looks like it is working properly. I have the carter bbd carb and I was wondering if this is a symptom of something wrong with it. I don't think that the fuel could be evaporating that quickly and I don't really think that the fuel is boiling in the carb as it does this after short drives also.
I honestly don't know where the fuel is going and that makes me nervous. Is it possible that fuel is just draining back into the tank?
Thanks in advance for any help.
-Aaron

 

[hole]

I had a pinhole that was allowing air in intermittently, found it by having my buddie carefully filling the fuel tank with air while I crawled around looking for the leak. Surprisingly it took a few minutes before a visible drip formed.
Second thought is vapor lock. How close to the exhaust is the fuel line?

 

[Torxhead]

Air could be getting into the fuel filter from an open needle & seat, no big deal.

 

[BusaDave9]

This is normal. My filter is clear and always has some air before I start the engine.

Air could be getting into the fuel filter from an open needle & seat, no big deal.

 

[Aaron]

This is normal. My filter is clear and always has some air before I start the engine.

How much air? Mine is nearly full of air. Do you need to crank your engine for 10 seconds when you start it to let the fuel pressure come up?

 

[Aaron]

Air could be getting into the fuel filter from an open needle & seat, no big deal.

I would agree that it is no big deal but I loose so much fuel that I have to crank the motor for at least 10 seconds before it starts. I didn't have this problem a week ago. It used to start right up.

 

[PaRenegade]

If your filter is one with three nozzles, is the offset one clocked at 12 (up)? Otherwise you might be draining down the overflow and back to the tank. If it's up then my second thought is your fuel pump may have a leak in one of it's valve seals, letting it drain back.

 

[Torxhead]

Yes, with a well vented carb fuel bowl gas can evaporate out. A check can be done to see if the accelerator pump is squirting gas down the carb. On the later model CJs the carb vent would close off to retain fuel in the bowl.

 

[Saddle Tramp]

Do you have a return fuel line to the tank with the dual outlet filter? The return outlet should be installed up which will let air and un-needed fuel to be pushed back to the tank. If set up this way you have no worries.

http://www.4wd.com/Jeep-Engine-Performance/In-Line-Fuel-Filter-Kit.aspx?t_c=74&t_s=383&t_pt=3461&t_pn=OAI17718.02