Ok so I've known about this fuel leak for a good while, and I finally decided to take a closer look today. I ran around town for while, then parked and popped the hood. The first thing I noted was some bubbling diesel coming out of the afc drip tube, I realize this is normal. I worked the throttle a bit to see what happened, and here is what I found... The lift pump and areas directly below it seem to be wet with diesel. The top of the fuel filter appears wet, which I diagnose as the leaky fuel heater. Also, I noticed some bit of vapor coming from behind the throttle linkage area, and that is where I got lost. Could it be some of the diesel thats leaking out just burning off, a blowby leak, or something else? Any ideas?

Thanks,
Cal

And please, if anything needs clarification, ask me!

Also, I am tossing around the idea of putting in an airdog 100 instead of fixing these issues... which would be more costly?

 

No, that's NOT normal. The o-ring around the fuel pin is leaking. You need to pull the pump top to replace it.

I'd change the fuel heater gasket and the fuel filter and clean the lift pump. Then go for a ride and see if the lift pump gets wet again.

Fuel heater gasket $4, Filter $12, VE pump seal kit $25, if the lift pump is bad add another $75. So worst case we are talking $120 vs. $500 for an Airdog.

 

it seems almost impossible that any seal inside that VE would be leaking, I had the pump completely rebuilt with all new seals like 2 years ago, right after I started using ULSD... Its not actually dripping diesel, theres just a little bit that comes out, but most of it is air that makes bubbles (I sat there and watched it for a bit). Is this still a problem?

 

Very doubtful he would have to buy a new lift pump every year, considering that is probably the original pump that is now ~17 years old with 200+k miles on it. So more like $120 every 20 years.

 

It might seem unlikely but the evidence is right in front of you. If fuel is coming out of the AFC vent then that o-ring is missing.

Our mechanical lift pumps generally last more than 10 years. Nice try though.

That said, I think the Airdog is the best of the bunch when it comes to complete "plug & play" fuel systems.