pumps if there is air (about four
without). Loosen the screw and watch for bubbles. Re-tighten the screw after
5 seconds or so, pump, loosen, repeat. Stop when the bubbles do. If you don’t
have any air in the lines at all, then you don’t have an air leak. If there
are, then you have a leak of some extent, but that alone probably doesn’t
guarantee it is a problem. I’m not exactly sure what is acceptable (maybe a
diesel expert out there could help out) but it sounds like 1-2 pump cycles of
air is okay. If it takes several cycles or more, then it’s
probably is something to look into seriously.
If the problem reoccurs, note exactly the conditions at which point it happens.
You could also recreate the conditions to see if you can make it happen
(safely). Very closely inspect the entire fuel line from the tank to the
injection pump. Pay particularly close attention to the connections at the
filter mount. My clamped connections were very loose (less than finger tight)
and seemed to have leaked. Another mentioned the same on one of the boards.
Several others reported their banjo bolts at the mount as being loose (one I
think identified that as his problem after replacing the seal), but mine seem
to be okay. The two or three owners who found their fuel filter mount to be
faulty discovered it by finding fuel leaking from the electrical plug after
pumping the primer button. The first suggested unplugging the connector,
pumping, and then inspecting for leaks. Also, ensure the fuel filter is nice
snug. A sight glass or clear section of fuel line will help in
troubleshooting. I’ve also been told to coat suspected connections or other
areas with heavy gear oil and to go driving. Any leak will leave a visible
hole in the coating. Of course, if you’ve got any codes set, they should clue
you in, although you’ll need to get a hold of a reader. Some autozones lend a
basic reader for free (sometimes for a deposit). I’ve been told that only the
dealership can read all codes. I’ve also heard that you can buy essentially
what the dealership uses, for a lot of money. However, I suspect that the
cheaper readers cover the basic territory just fine. I at least know that the
“large fuel leak” code also sets the check engine light and can be read by the
basic reader that the autozone near me lends out :D
It does seem to me that the computers in this and other newer vehicles have a
pretty good handle on the operational conditions of the engine. When things go
wrong, the computer usually picks it up. From my limited experience and what
I’ve read, it seems that an air leak may be a good starting point for this
vehicle when there are mysterious symptoms that could be explained by an air
leak and for which the computer hasn’t thrown a code. It’s at least something
that can cause a variety of symptoms while not triggering a code. I hope this
helps.
Mike
One other thought. You could just take it to the dealership, but ensure you do
not have any biodiesel in the tank (if there is any possibility it could be a
fuel system issue). Also, I definitely recommend the lostkjs.com forum,
particularly the diesel section. It’s a great resource; by far the best jeep
liberty forum there is for technical info.
- Original Message
From: Ryan King [EMAIL PROTECTED]
To: biofuel@sustainablelists.org
Sent: Wednesday, April 25, 2007 9:56:07 AM
Subject: Re: [Biofuel] Jeep diesels
Is this air leak problem a result of using B100 or is it a problem that occurs
regardless of fuel type? I have the same jeep/engine and I remember one time my
wife complained that the engine had no power and would not accelerate past
45mph, and after she stoped moving the engine stalled. Upon restart, she had
no problem. Now I wonder if it was an air leak. The problem has not happened
again since. I hope to get our jeep running on B100 soon.
- Original Message
From: fox mulder [EMAIL PROTECTED]
To: biofuel@sustainablelists.org
Sent: Wednesday, April 25, 2007 7:50:40 AM
Subject: Re: [Biofuel] Jeep diesels
--- Michael Friebel [EMAIL PROTECTED] wrote:
I have a few thousand miles on B100 in a 2006 U.S.
2.8L Jeep Liberty CRD. No problems other than an
ongoing fuel system air leak that appeared at about
2500 miles. It allows enough air into the system at
or near wide open throttle to trigger limp mode or
to cause the engine to die. This is particularly
likely when high throttle is used for an extended
period of time (such as climbing a hill while
towing). It may leak under other conditions as well
but at a level insufficient to affect operation. It
would initially cause these symptoms regardless of
the fuel, although they were much more likely when
running on biodiesel (higher viscosity). The
dealership changed the tank sender module first
section of fuel line from the tank and it since only
occurs when running on biodiesel (any percentage).
I should
