RE: [MV] CUCV Stalling

From: Stu (stuinnh@comcast.net)
Date: Mon Sep 15 2003 - 05:37:49 PDT


I have also installed 12v electric fuel pump. I have set it up to start
priming the system when I turn key to on position while glow plugs heat.
Saves on grinding the starter to bleed air when installing new diesel
filter.

                "Stu"
 Southern New Hampshire, USA
        "Live Free Or Die"
 
Military Vehicle Preservation Assoc.
Merrimack Valley Military Vehicle Collectors
Green Mountain Military Vehicle Club
Vehicles:
1967 M151A1 Jeep
1964 M416 1/4 Ton Trailer
1986 M1009 CUCV Blazer
 

-----Original Message-----
From: Military Vehicles Mailing List [mailto:mil-veh@mil-veh.org] On
Behalf Of Mark J. Blair
Sent: Sunday, September 14, 2003 10:37 PM
To: Military Vehicles Mailing List
Subject: Re: [MV] CUCV Stalling

Tom Kelly wrote:
> I'm guessing that maybe there is a pin-hole leak that lets air in the
> fuel system overnight. but don't have a clue where to look.

I haven't worked on a CUCV before, but if I'm not mistaken, it has the
same
6.2 liter V8 GM diesel as my HMMWV, so maybe I can help a bit. Here's
what I'd
do to narrow down the source of a potential air leak. First, I'd tee in
a
pressure meter in the line feeding fuel to the injection pump, after any
other
boost pump(s) or filter(s). I'd include a section of clear tubing, so
that I
could see if any air bubbles are present in the fuel (after bleeding out
the
air that got in while messing with the plumbing), and check the supply
pressure. On the HMMWV, which has a mechanical fuel boost pump on the
lower
right corner of the engine, there should be at least 4 PSI of fuel
pressure.
This is a low pressure line, and one of those vacuum gauges from Sears,
Pep
boys, etc. that can also measure around 15 PSI of pressure will work
fine. If
air bubbles are still present after a while, then air is getting in
somewhere
between the gauge and the fuel tank. If not, then restore the plumbing,
and
temporarily replace the hose coming off the top of the fuel injection
pump
(which is a bypass line, returning fuel to the tank) with a short
section of
clear hose. If, after a while, bubbles are still present, then there's
most
likely an air leak in the fuel injection pump, and it will need to be
rebuilt
or replaced. This is how I determined that my truck had a bad fuel
injection pump.

Anyway, before you try any of this stuff, learn how to properly bleed
the fuel
system after air has gotten in (you'll need to know this anyway if you
ever
let the fuel tank run dry). I don't know the procedure on a CUCV, but
it's
probably similar to the procedure for a HMMWV:

1. Open the bleed valve on the fuel filter, and crank the engine until
clean
fuel flows out with no more bubbles; close the valve. (If the CUCV has
an
electric in-tank pump instead of the mechanical pump that the HMMWV has,
then
you may just need to turn on the ignition, rather than cranking the
engine.)
Now clean up the mess you just made.

2. Temporarily remove the bleed hose from the top of the fuel injection
pump,
and crank the engine until clean fuel without bubble is coming out. Use
a
container to catch the fuel that comes out. Reattach the hose, then
clean up
any spills.

3. Slightly loosen the flare nuts which attach the metal fuel lines to
the
eight injectors, being careful to not allow the injectors to turn (two
wrenches are generally required. Crank the engine until fuel squirts out

around all eight flare nuts. Re-tighten the flare nuts, and clean up the
mess.

The fuel system should be purged at this point. I typed all of this in
from
memory (been there, bought the T shirt!), so somebody weigh in with
corrections if I made any mistakes.

GOod luck!

-- 
Mark J. Blair, NF6X <ke6myk@sbcglobal.net>
PGP 2.6.2 public key available from http://www.keyserver.net/
Web page: http://www.qsl.net/ke6myk/

===Mil-Veh is a member-supported mailing list=== To unsubscribe, send e-mail to: <mil-veh-off@mil-veh.org> To switch to the DIGEST mode, send e-mail to <mil-veh-digest@mil-veh.org> To reach a human, contact <ack@mil-veh.org>



This archive was generated by hypermail 2.1.4 : Sat May 07 2005 - 20:24:25 PDT