IMHO:
#1 suspect = condenser- lots of unexplained problems turn out to be this!
#2 suspect = fuel filter- check (or replace) the in-tank as well as the
carburetor filter.
#3 suspect = fuel return system- if you've got the later smog style setup,
there is an orifice in the carb inlet that bypasses fuel back to the tank.
This sets up a high fuel flow rate in the system to prevent vapor lock.
#4 suspect = carb- internal leakage, needs gaskets or overhaul.
#5 suspect = water in the fuel- condensation or ? Drain some gas out of the
bottom of the tank (and make sure it's gas, not pure water!).
#6 suspect = fuel pump pressure regulator/check valve failed, or fuel pump
arm (or engine cam lobe) worn.
Anyhow, check the fuel pressure at the carb inlet, it should be about 7 psi
as I recall (and should bounce around a bit at idle). If it isn't, it's a
supply problem, either the fuel tank filter is clogged, or the fuel pump
needs repair. If it stays at 7 psi even after shut down, the return line is
clogged. It should drop to zero immediately after the engine stops turning.
I replaced the metal filter at the carb inlet with a clear plastic paper
element one so I could see that it wasn't clogged. The stock one always
leaves you wondering! Don't buy those glass replaceable element ones, the
filter screen doesn't have much capacity.
In one incident, my jeep kept sputtering and dying, but after the jeep sat
for about 20 minutes, it would start again and run fine for 5 minutes or
less. It turned out that the metal filter at the carb was clogged, when the
fuel pressure would subside, the particles would fall out of the filter
media. Once you started it up, the filter packed up again. Since the filter
was ahead of the return orifice, virtually no pressure was getting to the
carb since the orifice design requires an excess of fuel volume to work
properly.
BK
----- Original Message -----
From: "Ken Boge" <ken@clovermachine.com>
To: "Military Veh List" <mil-veh@skylee.com>
Sent: Monday, November 29, 1999 4:49 PM
Subject: [MV] Sputtering Mutt
Hi List,
I'm having a problem with my M151A2 Mutt (Jeep) thats been frustrating me
for several days now. Your help would be appreciated.
The vehicle runs fairly well at low rpm or when I have the accelerator to
the floor, but in between it sputters and coughs and has no power or
acceleration. I checked the distributor advance just in case and all the
parts seem to be working properly.
It has a Zenith carburetor. A friend suggested I adjust the float level so
I tried moving the float up and down . Didn't seem to make a difference.
I thought the accelerator pump may be bad but I couldn't find what looked
like a "normal" accelerator pump in the carburetor. At the bottom of the
float bowl there is a housing with a diaphragm. The diaphragm had some
cracks in it so I replaced it with one from an older spare carb. No
difference. If anyone has any suggestions please let me know.
Thanks,
Ken
M35A2
M151A2
===
To unsubscribe from the mil-veh mailing list, send the single word
UNSUBSCRIBE in the body of a message to <mil-veh-request@skylee.com>.
__________________________________________
NetZero - Defenders of the Free World
Get your FREE Internet Access and Email at
http://www.netzero.net/download/index.html
===
To unsubscribe from the mil-veh mailing list, send the single word
UNSUBSCRIBE in the body of a message to <mil-veh-request@skylee.com>.