Intermittent air leak

Most of the time the fuel is draining back to the tank after 1 day of sitting. Sat for a week last week and was fine. Pulling my hair out at this one. So far I have:

replaced the sensor on the back of the fuel filter housing,
electric lift pump to the mechanical one.
3 years ago new sending unit
3 years ago rebuilt injection pump

Have you replaced the fuel filter? I have had the same problem off and on, this is what I found on the old filter. I noticed a fuel odor and a small amount of fuel on the motor below the filter. My local parts store had the filter in stock.

I tried replacing sensor once and it ended up leaking again. Gobbed it full of RTV ultra and it held for a while. Then I found out about the improved filter bases. They are the same but hole feeding fuel to sensor was not drilled through and no sensor was used. Plug the hole and leave out sensor and you have about the same thing. JB weld or similar should work.

Fuel pressure sensor was just for STE-ICE, I believe.

I recall someone saying he had just put a bolt in the hole with some JB Weld. Problem solved. IIRC, it was a standard 1/4-20, but I could be wrong about that.

dependable is correct - the sensor is just for STE-ICE, so it's not needed.


Better yet, get rid of the whole thing and replace it with a modern spin-on filter setup.

There are a lot of spin on options. A common one is to use the filter base for the 33123(wix) or 3123(napa). This filter was used in early civy 6.2s in conjunction with secondary filter and a line mounted fuel heater under the intake manifold. The stock CUCV base works fine once the sensor hole is blocked and has a fuel heater and water in fuel sensor.

If I were going to bother changing to spin ons, I would get something good with a fuel heater, good filtering capacity and possibly a clear bottom to check for water and debris. I have too many of these trucks to justify that expense when stock system, once fixed, is working.

i want to keep things original, and i have a bunch of factory square can filters. here is what i have done .
this was a practice filter base. dont remember the size of the tap. used a little thread tape. thanks. mark

Switched out the whole filter assembly and filter. And same results. I'm gonna do the lift pump this weekend and check all the fuel lines/ replace.