Starting Problems
09-29-2005, 10:35 PM
#21
Guest
Posts: n/a
Re: Starting Problems
fuel pump bleding down
McNick wrote:
> It will start up great if you turn it off then start it again, but when you
> let it sit for about a hou, it will be hard to start again, It is hard to
> start about 90% of the time, Could you help?
McNick wrote:
> It will start up great if you turn it off then start it again, but when you
> let it sit for about a hou, it will be hard to start again, It is hard to
> start about 90% of the time, Could you help?
09-29-2005, 10:35 PM
#22
Guest
Posts: n/a
Re: Starting Problems
fuel pump bleding down
McNick wrote:
> It will start up great if you turn it off then start it again, but when you
> let it sit for about a hou, it will be hard to start again, It is hard to
> start about 90% of the time, Could you help?
McNick wrote:
> It will start up great if you turn it off then start it again, but when you
> let it sit for about a hou, it will be hard to start again, It is hard to
> start about 90% of the time, Could you help?
09-29-2005, 10:50 PM
#23
Guest
Posts: n/a
Re: Starting Problems
McNick did pass the time by typing:
> It will start up great if you turn it off then start it again, but when you
> let it sit for about a hou, it will be hard to start again, It is hard to
> start about 90% of the time, Could you help?
Fuel pressure bleed off. Could be the regulator or the valve in the fuel
pump is letting the rail pressure drop. Figuring out which one is not easy
without the tools for shutting off the supply lines.
Stick a fuel pressure gauge on there and see what it says.
(an old R-12 low side gauge makes a good tester since you can tape it
to the windshield)
In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
then turn the key off, then back on again, after the buzz then start.
--
DougW
> It will start up great if you turn it off then start it again, but when you
> let it sit for about a hou, it will be hard to start again, It is hard to
> start about 90% of the time, Could you help?
Fuel pressure bleed off. Could be the regulator or the valve in the fuel
pump is letting the rail pressure drop. Figuring out which one is not easy
without the tools for shutting off the supply lines.
Stick a fuel pressure gauge on there and see what it says.
(an old R-12 low side gauge makes a good tester since you can tape it
to the windshield)
In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
then turn the key off, then back on again, after the buzz then start.
--
DougW
09-29-2005, 10:50 PM
#24
Guest
Posts: n/a
Re: Starting Problems
McNick did pass the time by typing:
> It will start up great if you turn it off then start it again, but when you
> let it sit for about a hou, it will be hard to start again, It is hard to
> start about 90% of the time, Could you help?
Fuel pressure bleed off. Could be the regulator or the valve in the fuel
pump is letting the rail pressure drop. Figuring out which one is not easy
without the tools for shutting off the supply lines.
Stick a fuel pressure gauge on there and see what it says.
(an old R-12 low side gauge makes a good tester since you can tape it
to the windshield)
In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
then turn the key off, then back on again, after the buzz then start.
--
DougW
> It will start up great if you turn it off then start it again, but when you
> let it sit for about a hou, it will be hard to start again, It is hard to
> start about 90% of the time, Could you help?
Fuel pressure bleed off. Could be the regulator or the valve in the fuel
pump is letting the rail pressure drop. Figuring out which one is not easy
without the tools for shutting off the supply lines.
Stick a fuel pressure gauge on there and see what it says.
(an old R-12 low side gauge makes a good tester since you can tape it
to the windshield)
In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
then turn the key off, then back on again, after the buzz then start.
--
DougW
09-29-2005, 10:50 PM
#25
Guest
Posts: n/a
Re: Starting Problems
McNick did pass the time by typing:
> It will start up great if you turn it off then start it again, but when you
> let it sit for about a hou, it will be hard to start again, It is hard to
> start about 90% of the time, Could you help?
Fuel pressure bleed off. Could be the regulator or the valve in the fuel
pump is letting the rail pressure drop. Figuring out which one is not easy
without the tools for shutting off the supply lines.
Stick a fuel pressure gauge on there and see what it says.
(an old R-12 low side gauge makes a good tester since you can tape it
to the windshield)
In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
then turn the key off, then back on again, after the buzz then start.
--
DougW
> It will start up great if you turn it off then start it again, but when you
> let it sit for about a hou, it will be hard to start again, It is hard to
> start about 90% of the time, Could you help?
Fuel pressure bleed off. Could be the regulator or the valve in the fuel
pump is letting the rail pressure drop. Figuring out which one is not easy
without the tools for shutting off the supply lines.
Stick a fuel pressure gauge on there and see what it says.
(an old R-12 low side gauge makes a good tester since you can tape it
to the windshield)
In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
then turn the key off, then back on again, after the buzz then start.
--
DougW
09-30-2005, 12:01 AM
#26
Guest
Posts: n/a
Re: Starting Problems
Info from manual
FUEL PRESSURE LEAK DOWN TEST
Use this test in conjunction with the Fuel Pump
Pressure Test and Fuel Pump Capacity Test.
Check Valve Operation: The electric fuel pump
outlet contains a one-way check valve to prevent fuel
flow back into the tank and to maintain fuel supply
line pressure (engine warm) when pump is not operational.
It is also used to keep the fuel supply line
full of gasoline when pump is not operational. After
the vehicle has cooled down, fuel pressure may drop
to 0 psi (cold fluid contracts), but liquid gasoline will
remain in fuel supply line between the check valve
and fuel injectors. Fuel pressure that has
dropped to 0 psi on a cooled down vehicle
(engine off) is a normal condition. When the electric
fuel pump is activated, fuel pressure should
immediately (1–2 seconds) rise to specification.
Abnormally long periods of cranking to restart a
hot engine that has been shut down for a short
period of time may be caused by:
² Fuel pressure bleeding past a fuel injector(s).
² Fuel pressure bleeding past the check valve in
the fuel pump module.
(1) Disconnect the fuel inlet line at fuel rail. Refer
to Fuel Tubes/Lines/Hoses and Clamps in this section
of the group for procedures. On some engines, air
cleaner housing removal may be necessary before
fuel line disconnection.
(2) Obtain correct Fuel Line Pressure Test Adapter
Tool Hose. Tool number 6539 is used for 5/16” fuel
lines and tool number 6631 is used for 3/8” fuel lines.
(3) Connect correct Fuel Line Pressure Test
Adapter Tool Hose between disconnected fuel line
and fuel rail (Fig. 11).
(4) Connect the 0-414 kPa (0-60 psi) fuel pressure
test gauge (from Gauge Set 5069) to the test port on
the appropriate Adaptor Tool. The fittings on both
tools must be in good condition and free from
any small leaks before performing the proceeding
test.
(5) Start engine and bring to normal operating
temperature.
(6) Observe test gauge. Normal operating pressure
should be 339 kPa 6 34 kPa (49.2 psi 6 5 psi).
(7) Shut engine off.
(8) Pressure should not fall below 30 psi for five
minutes.
(9) If pressure falls below 30 psi, it must be determined
if a fuel injector, the check valve within the
fuel pump module, or a fuel tube/line is leaking.
(10) Again, start engine and bring to normal operating
temperature.
(11) Shut engine off.
(12) Testing for fuel injector or fuel rail leakage:
Clamp off the rubber hose portion of Adaptor
Tool between the fuel rail and the test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a fuel injector or the fuel rail is leaking.
(13) Testing for fuel pump check valve, filter/
regulator check valve or fuel tube/line leakage:
Clamp off the rubber hose portion of Adaptor Tool
between the vehicle fuel line and test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a leak may be found at a fuel tube/line. If no
leaks are found at fuel tubes or lines, one of the
check valves in either the electric fuel pump or filter/
regulator may be leaking.
Note: A quick loss of pressure usually indicates a
defective check valve in the filter/regulator. A slow
loss of pressure usually indicates a defective check
valve in the electric fuel pump.
The electric fuel pump is not serviced separately.
Replace the fuel pump module assembly. The filter/regulator
may be replaced separately on certain applications.
Refer to Fuel Filter/Fuel Pressure Regulator
Removal/Installation for additional information.
--
Billy_Ray@SPAM.fuse.net (remove SPAM)
2002 Jeep WJ 4 Liter Automatic
Sharing is why we are all here....... or should be.
..
"DougW" <post.replies@invalid.address> wrote in message
news:%J1%e.8397$P34.2425@okepread07...
> McNick did pass the time by typing:
>> It will start up great if you turn it off then start it again, but when
>> you
>> let it sit for about a hou, it will be hard to start again, It is hard to
>> start about 90% of the time, Could you help?
>
> Fuel pressure bleed off. Could be the regulator or the valve in the fuel
> pump is letting the rail pressure drop. Figuring out which one is not
> easy
> without the tools for shutting off the supply lines.
>
> Stick a fuel pressure gauge on there and see what it says.
> (an old R-12 low side gauge makes a good tester since you can tape it
> to the windshield)
>
> In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
> then turn the key off, then back on again, after the buzz then start.
>
> --
> DougW
>
FUEL PRESSURE LEAK DOWN TEST
Use this test in conjunction with the Fuel Pump
Pressure Test and Fuel Pump Capacity Test.
Check Valve Operation: The electric fuel pump
outlet contains a one-way check valve to prevent fuel
flow back into the tank and to maintain fuel supply
line pressure (engine warm) when pump is not operational.
It is also used to keep the fuel supply line
full of gasoline when pump is not operational. After
the vehicle has cooled down, fuel pressure may drop
to 0 psi (cold fluid contracts), but liquid gasoline will
remain in fuel supply line between the check valve
and fuel injectors. Fuel pressure that has
dropped to 0 psi on a cooled down vehicle
(engine off) is a normal condition. When the electric
fuel pump is activated, fuel pressure should
immediately (1–2 seconds) rise to specification.
Abnormally long periods of cranking to restart a
hot engine that has been shut down for a short
period of time may be caused by:
² Fuel pressure bleeding past a fuel injector(s).
² Fuel pressure bleeding past the check valve in
the fuel pump module.
(1) Disconnect the fuel inlet line at fuel rail. Refer
to Fuel Tubes/Lines/Hoses and Clamps in this section
of the group for procedures. On some engines, air
cleaner housing removal may be necessary before
fuel line disconnection.
(2) Obtain correct Fuel Line Pressure Test Adapter
Tool Hose. Tool number 6539 is used for 5/16” fuel
lines and tool number 6631 is used for 3/8” fuel lines.
(3) Connect correct Fuel Line Pressure Test
Adapter Tool Hose between disconnected fuel line
and fuel rail (Fig. 11).
(4) Connect the 0-414 kPa (0-60 psi) fuel pressure
test gauge (from Gauge Set 5069) to the test port on
the appropriate Adaptor Tool. The fittings on both
tools must be in good condition and free from
any small leaks before performing the proceeding
test.
(5) Start engine and bring to normal operating
temperature.
(6) Observe test gauge. Normal operating pressure
should be 339 kPa 6 34 kPa (49.2 psi 6 5 psi).
(7) Shut engine off.
(8) Pressure should not fall below 30 psi for five
minutes.
(9) If pressure falls below 30 psi, it must be determined
if a fuel injector, the check valve within the
fuel pump module, or a fuel tube/line is leaking.
(10) Again, start engine and bring to normal operating
temperature.
(11) Shut engine off.
(12) Testing for fuel injector or fuel rail leakage:
Clamp off the rubber hose portion of Adaptor
Tool between the fuel rail and the test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a fuel injector or the fuel rail is leaking.
(13) Testing for fuel pump check valve, filter/
regulator check valve or fuel tube/line leakage:
Clamp off the rubber hose portion of Adaptor Tool
between the vehicle fuel line and test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a leak may be found at a fuel tube/line. If no
leaks are found at fuel tubes or lines, one of the
check valves in either the electric fuel pump or filter/
regulator may be leaking.
Note: A quick loss of pressure usually indicates a
defective check valve in the filter/regulator. A slow
loss of pressure usually indicates a defective check
valve in the electric fuel pump.
The electric fuel pump is not serviced separately.
Replace the fuel pump module assembly. The filter/regulator
may be replaced separately on certain applications.
Refer to Fuel Filter/Fuel Pressure Regulator
Removal/Installation for additional information.
--
Billy_Ray@SPAM.fuse.net (remove SPAM)
2002 Jeep WJ 4 Liter Automatic
Sharing is why we are all here....... or should be.
..
"DougW" <post.replies@invalid.address> wrote in message
news:%J1%e.8397$P34.2425@okepread07...
> McNick did pass the time by typing:
>> It will start up great if you turn it off then start it again, but when
>> you
>> let it sit for about a hou, it will be hard to start again, It is hard to
>> start about 90% of the time, Could you help?
>
> Fuel pressure bleed off. Could be the regulator or the valve in the fuel
> pump is letting the rail pressure drop. Figuring out which one is not
> easy
> without the tools for shutting off the supply lines.
>
> Stick a fuel pressure gauge on there and see what it says.
> (an old R-12 low side gauge makes a good tester since you can tape it
> to the windshield)
>
> In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
> then turn the key off, then back on again, after the buzz then start.
>
> --
> DougW
>
09-30-2005, 12:01 AM
#27
Guest
Posts: n/a
Re: Starting Problems
Info from manual
FUEL PRESSURE LEAK DOWN TEST
Use this test in conjunction with the Fuel Pump
Pressure Test and Fuel Pump Capacity Test.
Check Valve Operation: The electric fuel pump
outlet contains a one-way check valve to prevent fuel
flow back into the tank and to maintain fuel supply
line pressure (engine warm) when pump is not operational.
It is also used to keep the fuel supply line
full of gasoline when pump is not operational. After
the vehicle has cooled down, fuel pressure may drop
to 0 psi (cold fluid contracts), but liquid gasoline will
remain in fuel supply line between the check valve
and fuel injectors. Fuel pressure that has
dropped to 0 psi on a cooled down vehicle
(engine off) is a normal condition. When the electric
fuel pump is activated, fuel pressure should
immediately (1–2 seconds) rise to specification.
Abnormally long periods of cranking to restart a
hot engine that has been shut down for a short
period of time may be caused by:
² Fuel pressure bleeding past a fuel injector(s).
² Fuel pressure bleeding past the check valve in
the fuel pump module.
(1) Disconnect the fuel inlet line at fuel rail. Refer
to Fuel Tubes/Lines/Hoses and Clamps in this section
of the group for procedures. On some engines, air
cleaner housing removal may be necessary before
fuel line disconnection.
(2) Obtain correct Fuel Line Pressure Test Adapter
Tool Hose. Tool number 6539 is used for 5/16” fuel
lines and tool number 6631 is used for 3/8” fuel lines.
(3) Connect correct Fuel Line Pressure Test
Adapter Tool Hose between disconnected fuel line
and fuel rail (Fig. 11).
(4) Connect the 0-414 kPa (0-60 psi) fuel pressure
test gauge (from Gauge Set 5069) to the test port on
the appropriate Adaptor Tool. The fittings on both
tools must be in good condition and free from
any small leaks before performing the proceeding
test.
(5) Start engine and bring to normal operating
temperature.
(6) Observe test gauge. Normal operating pressure
should be 339 kPa 6 34 kPa (49.2 psi 6 5 psi).
(7) Shut engine off.
(8) Pressure should not fall below 30 psi for five
minutes.
(9) If pressure falls below 30 psi, it must be determined
if a fuel injector, the check valve within the
fuel pump module, or a fuel tube/line is leaking.
(10) Again, start engine and bring to normal operating
temperature.
(11) Shut engine off.
(12) Testing for fuel injector or fuel rail leakage:
Clamp off the rubber hose portion of Adaptor
Tool between the fuel rail and the test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a fuel injector or the fuel rail is leaking.
(13) Testing for fuel pump check valve, filter/
regulator check valve or fuel tube/line leakage:
Clamp off the rubber hose portion of Adaptor Tool
between the vehicle fuel line and test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a leak may be found at a fuel tube/line. If no
leaks are found at fuel tubes or lines, one of the
check valves in either the electric fuel pump or filter/
regulator may be leaking.
Note: A quick loss of pressure usually indicates a
defective check valve in the filter/regulator. A slow
loss of pressure usually indicates a defective check
valve in the electric fuel pump.
The electric fuel pump is not serviced separately.
Replace the fuel pump module assembly. The filter/regulator
may be replaced separately on certain applications.
Refer to Fuel Filter/Fuel Pressure Regulator
Removal/Installation for additional information.
--
Billy_Ray@SPAM.fuse.net (remove SPAM)
2002 Jeep WJ 4 Liter Automatic
Sharing is why we are all here....... or should be.
..
"DougW" <post.replies@invalid.address> wrote in message
news:%J1%e.8397$P34.2425@okepread07...
> McNick did pass the time by typing:
>> It will start up great if you turn it off then start it again, but when
>> you
>> let it sit for about a hou, it will be hard to start again, It is hard to
>> start about 90% of the time, Could you help?
>
> Fuel pressure bleed off. Could be the regulator or the valve in the fuel
> pump is letting the rail pressure drop. Figuring out which one is not
> easy
> without the tools for shutting off the supply lines.
>
> Stick a fuel pressure gauge on there and see what it says.
> (an old R-12 low side gauge makes a good tester since you can tape it
> to the windshield)
>
> In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
> then turn the key off, then back on again, after the buzz then start.
>
> --
> DougW
>
FUEL PRESSURE LEAK DOWN TEST
Use this test in conjunction with the Fuel Pump
Pressure Test and Fuel Pump Capacity Test.
Check Valve Operation: The electric fuel pump
outlet contains a one-way check valve to prevent fuel
flow back into the tank and to maintain fuel supply
line pressure (engine warm) when pump is not operational.
It is also used to keep the fuel supply line
full of gasoline when pump is not operational. After
the vehicle has cooled down, fuel pressure may drop
to 0 psi (cold fluid contracts), but liquid gasoline will
remain in fuel supply line between the check valve
and fuel injectors. Fuel pressure that has
dropped to 0 psi on a cooled down vehicle
(engine off) is a normal condition. When the electric
fuel pump is activated, fuel pressure should
immediately (1–2 seconds) rise to specification.
Abnormally long periods of cranking to restart a
hot engine that has been shut down for a short
period of time may be caused by:
² Fuel pressure bleeding past a fuel injector(s).
² Fuel pressure bleeding past the check valve in
the fuel pump module.
(1) Disconnect the fuel inlet line at fuel rail. Refer
to Fuel Tubes/Lines/Hoses and Clamps in this section
of the group for procedures. On some engines, air
cleaner housing removal may be necessary before
fuel line disconnection.
(2) Obtain correct Fuel Line Pressure Test Adapter
Tool Hose. Tool number 6539 is used for 5/16” fuel
lines and tool number 6631 is used for 3/8” fuel lines.
(3) Connect correct Fuel Line Pressure Test
Adapter Tool Hose between disconnected fuel line
and fuel rail (Fig. 11).
(4) Connect the 0-414 kPa (0-60 psi) fuel pressure
test gauge (from Gauge Set 5069) to the test port on
the appropriate Adaptor Tool. The fittings on both
tools must be in good condition and free from
any small leaks before performing the proceeding
test.
(5) Start engine and bring to normal operating
temperature.
(6) Observe test gauge. Normal operating pressure
should be 339 kPa 6 34 kPa (49.2 psi 6 5 psi).
(7) Shut engine off.
(8) Pressure should not fall below 30 psi for five
minutes.
(9) If pressure falls below 30 psi, it must be determined
if a fuel injector, the check valve within the
fuel pump module, or a fuel tube/line is leaking.
(10) Again, start engine and bring to normal operating
temperature.
(11) Shut engine off.
(12) Testing for fuel injector or fuel rail leakage:
Clamp off the rubber hose portion of Adaptor
Tool between the fuel rail and the test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a fuel injector or the fuel rail is leaking.
(13) Testing for fuel pump check valve, filter/
regulator check valve or fuel tube/line leakage:
Clamp off the rubber hose portion of Adaptor Tool
between the vehicle fuel line and test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a leak may be found at a fuel tube/line. If no
leaks are found at fuel tubes or lines, one of the
check valves in either the electric fuel pump or filter/
regulator may be leaking.
Note: A quick loss of pressure usually indicates a
defective check valve in the filter/regulator. A slow
loss of pressure usually indicates a defective check
valve in the electric fuel pump.
The electric fuel pump is not serviced separately.
Replace the fuel pump module assembly. The filter/regulator
may be replaced separately on certain applications.
Refer to Fuel Filter/Fuel Pressure Regulator
Removal/Installation for additional information.
--
Billy_Ray@SPAM.fuse.net (remove SPAM)
2002 Jeep WJ 4 Liter Automatic
Sharing is why we are all here....... or should be.
..
"DougW" <post.replies@invalid.address> wrote in message
news:%J1%e.8397$P34.2425@okepread07...
> McNick did pass the time by typing:
>> It will start up great if you turn it off then start it again, but when
>> you
>> let it sit for about a hou, it will be hard to start again, It is hard to
>> start about 90% of the time, Could you help?
>
> Fuel pressure bleed off. Could be the regulator or the valve in the fuel
> pump is letting the rail pressure drop. Figuring out which one is not
> easy
> without the tools for shutting off the supply lines.
>
> Stick a fuel pressure gauge on there and see what it says.
> (an old R-12 low side gauge makes a good tester since you can tape it
> to the windshield)
>
> In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
> then turn the key off, then back on again, after the buzz then start.
>
> --
> DougW
>
09-30-2005, 12:01 AM
#28
Guest
Posts: n/a
Re: Starting Problems
Info from manual
FUEL PRESSURE LEAK DOWN TEST
Use this test in conjunction with the Fuel Pump
Pressure Test and Fuel Pump Capacity Test.
Check Valve Operation: The electric fuel pump
outlet contains a one-way check valve to prevent fuel
flow back into the tank and to maintain fuel supply
line pressure (engine warm) when pump is not operational.
It is also used to keep the fuel supply line
full of gasoline when pump is not operational. After
the vehicle has cooled down, fuel pressure may drop
to 0 psi (cold fluid contracts), but liquid gasoline will
remain in fuel supply line between the check valve
and fuel injectors. Fuel pressure that has
dropped to 0 psi on a cooled down vehicle
(engine off) is a normal condition. When the electric
fuel pump is activated, fuel pressure should
immediately (1–2 seconds) rise to specification.
Abnormally long periods of cranking to restart a
hot engine that has been shut down for a short
period of time may be caused by:
² Fuel pressure bleeding past a fuel injector(s).
² Fuel pressure bleeding past the check valve in
the fuel pump module.
(1) Disconnect the fuel inlet line at fuel rail. Refer
to Fuel Tubes/Lines/Hoses and Clamps in this section
of the group for procedures. On some engines, air
cleaner housing removal may be necessary before
fuel line disconnection.
(2) Obtain correct Fuel Line Pressure Test Adapter
Tool Hose. Tool number 6539 is used for 5/16” fuel
lines and tool number 6631 is used for 3/8” fuel lines.
(3) Connect correct Fuel Line Pressure Test
Adapter Tool Hose between disconnected fuel line
and fuel rail (Fig. 11).
(4) Connect the 0-414 kPa (0-60 psi) fuel pressure
test gauge (from Gauge Set 5069) to the test port on
the appropriate Adaptor Tool. The fittings on both
tools must be in good condition and free from
any small leaks before performing the proceeding
test.
(5) Start engine and bring to normal operating
temperature.
(6) Observe test gauge. Normal operating pressure
should be 339 kPa 6 34 kPa (49.2 psi 6 5 psi).
(7) Shut engine off.
(8) Pressure should not fall below 30 psi for five
minutes.
(9) If pressure falls below 30 psi, it must be determined
if a fuel injector, the check valve within the
fuel pump module, or a fuel tube/line is leaking.
(10) Again, start engine and bring to normal operating
temperature.
(11) Shut engine off.
(12) Testing for fuel injector or fuel rail leakage:
Clamp off the rubber hose portion of Adaptor
Tool between the fuel rail and the test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a fuel injector or the fuel rail is leaking.
(13) Testing for fuel pump check valve, filter/
regulator check valve or fuel tube/line leakage:
Clamp off the rubber hose portion of Adaptor Tool
between the vehicle fuel line and test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a leak may be found at a fuel tube/line. If no
leaks are found at fuel tubes or lines, one of the
check valves in either the electric fuel pump or filter/
regulator may be leaking.
Note: A quick loss of pressure usually indicates a
defective check valve in the filter/regulator. A slow
loss of pressure usually indicates a defective check
valve in the electric fuel pump.
The electric fuel pump is not serviced separately.
Replace the fuel pump module assembly. The filter/regulator
may be replaced separately on certain applications.
Refer to Fuel Filter/Fuel Pressure Regulator
Removal/Installation for additional information.
--
Billy_Ray@SPAM.fuse.net (remove SPAM)
2002 Jeep WJ 4 Liter Automatic
Sharing is why we are all here....... or should be.
..
"DougW" <post.replies@invalid.address> wrote in message
news:%J1%e.8397$P34.2425@okepread07...
> McNick did pass the time by typing:
>> It will start up great if you turn it off then start it again, but when
>> you
>> let it sit for about a hou, it will be hard to start again, It is hard to
>> start about 90% of the time, Could you help?
>
> Fuel pressure bleed off. Could be the regulator or the valve in the fuel
> pump is letting the rail pressure drop. Figuring out which one is not
> easy
> without the tools for shutting off the supply lines.
>
> Stick a fuel pressure gauge on there and see what it says.
> (an old R-12 low side gauge makes a good tester since you can tape it
> to the windshield)
>
> In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
> then turn the key off, then back on again, after the buzz then start.
>
> --
> DougW
>
FUEL PRESSURE LEAK DOWN TEST
Use this test in conjunction with the Fuel Pump
Pressure Test and Fuel Pump Capacity Test.
Check Valve Operation: The electric fuel pump
outlet contains a one-way check valve to prevent fuel
flow back into the tank and to maintain fuel supply
line pressure (engine warm) when pump is not operational.
It is also used to keep the fuel supply line
full of gasoline when pump is not operational. After
the vehicle has cooled down, fuel pressure may drop
to 0 psi (cold fluid contracts), but liquid gasoline will
remain in fuel supply line between the check valve
and fuel injectors. Fuel pressure that has
dropped to 0 psi on a cooled down vehicle
(engine off) is a normal condition. When the electric
fuel pump is activated, fuel pressure should
immediately (1–2 seconds) rise to specification.
Abnormally long periods of cranking to restart a
hot engine that has been shut down for a short
period of time may be caused by:
² Fuel pressure bleeding past a fuel injector(s).
² Fuel pressure bleeding past the check valve in
the fuel pump module.
(1) Disconnect the fuel inlet line at fuel rail. Refer
to Fuel Tubes/Lines/Hoses and Clamps in this section
of the group for procedures. On some engines, air
cleaner housing removal may be necessary before
fuel line disconnection.
(2) Obtain correct Fuel Line Pressure Test Adapter
Tool Hose. Tool number 6539 is used for 5/16” fuel
lines and tool number 6631 is used for 3/8” fuel lines.
(3) Connect correct Fuel Line Pressure Test
Adapter Tool Hose between disconnected fuel line
and fuel rail (Fig. 11).
(4) Connect the 0-414 kPa (0-60 psi) fuel pressure
test gauge (from Gauge Set 5069) to the test port on
the appropriate Adaptor Tool. The fittings on both
tools must be in good condition and free from
any small leaks before performing the proceeding
test.
(5) Start engine and bring to normal operating
temperature.
(6) Observe test gauge. Normal operating pressure
should be 339 kPa 6 34 kPa (49.2 psi 6 5 psi).
(7) Shut engine off.
(8) Pressure should not fall below 30 psi for five
minutes.
(9) If pressure falls below 30 psi, it must be determined
if a fuel injector, the check valve within the
fuel pump module, or a fuel tube/line is leaking.
(10) Again, start engine and bring to normal operating
temperature.
(11) Shut engine off.
(12) Testing for fuel injector or fuel rail leakage:
Clamp off the rubber hose portion of Adaptor
Tool between the fuel rail and the test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a fuel injector or the fuel rail is leaking.
(13) Testing for fuel pump check valve, filter/
regulator check valve or fuel tube/line leakage:
Clamp off the rubber hose portion of Adaptor Tool
between the vehicle fuel line and test port “T” on
Adapter Tool. If pressure now holds at or above 30
psi, a leak may be found at a fuel tube/line. If no
leaks are found at fuel tubes or lines, one of the
check valves in either the electric fuel pump or filter/
regulator may be leaking.
Note: A quick loss of pressure usually indicates a
defective check valve in the filter/regulator. A slow
loss of pressure usually indicates a defective check
valve in the electric fuel pump.
The electric fuel pump is not serviced separately.
Replace the fuel pump module assembly. The filter/regulator
may be replaced separately on certain applications.
Refer to Fuel Filter/Fuel Pressure Regulator
Removal/Installation for additional information.
--
Billy_Ray@SPAM.fuse.net (remove SPAM)
2002 Jeep WJ 4 Liter Automatic
Sharing is why we are all here....... or should be.
..
"DougW" <post.replies@invalid.address> wrote in message
news:%J1%e.8397$P34.2425@okepread07...
> McNick did pass the time by typing:
>> It will start up great if you turn it off then start it again, but when
>> you
>> let it sit for about a hou, it will be hard to start again, It is hard to
>> start about 90% of the time, Could you help?
>
> Fuel pressure bleed off. Could be the regulator or the valve in the fuel
> pump is letting the rail pressure drop. Figuring out which one is not
> easy
> without the tools for shutting off the supply lines.
>
> Stick a fuel pressure gauge on there and see what it says.
> (an old R-12 low side gauge makes a good tester since you can tape it
> to the windshield)
>
> In the meanwhile turn the key on, wait for the fuel pump to stop buzzing
> then turn the key off, then back on again, after the buzz then start.
>
> --
> DougW
>
09-30-2005, 10:56 PM
#29
Guest
Posts: n/a
Re: Starting Problems
McNick proclaimed:
> I have a 1998 Jeep Grand Cherokee, and for about two weeks now its taking
> alot longer to start, normally it will start right up within the first
> crank, but now it will crank over 5 to 6 times before starting... What
> could that be?
>
Better than cranking 12-16 times?
Turn the key on without starting. Count to 5. Turn the key off, and
then go straight to start. If that solves it, is simple fuel leakdown
which is easier to ignore than cure. Other than that, when is the
last time you had the vehicle serviced such as plugs, etc.?
> I have a 1998 Jeep Grand Cherokee, and for about two weeks now its taking
> alot longer to start, normally it will start right up within the first
> crank, but now it will crank over 5 to 6 times before starting... What
> could that be?
>
Better than cranking 12-16 times?
Turn the key on without starting. Count to 5. Turn the key off, and
then go straight to start. If that solves it, is simple fuel leakdown
which is easier to ignore than cure. Other than that, when is the
last time you had the vehicle serviced such as plugs, etc.?
09-30-2005, 10:56 PM
#30
Guest
Posts: n/a
Re: Starting Problems
McNick proclaimed:
> I have a 1998 Jeep Grand Cherokee, and for about two weeks now its taking
> alot longer to start, normally it will start right up within the first
> crank, but now it will crank over 5 to 6 times before starting... What
> could that be?
>
Better than cranking 12-16 times?
Turn the key on without starting. Count to 5. Turn the key off, and
then go straight to start. If that solves it, is simple fuel leakdown
which is easier to ignore than cure. Other than that, when is the
last time you had the vehicle serviced such as plugs, etc.?
> I have a 1998 Jeep Grand Cherokee, and for about two weeks now its taking
> alot longer to start, normally it will start right up within the first
> crank, but now it will crank over 5 to 6 times before starting... What
> could that be?
>
Better than cranking 12-16 times?
Turn the key on without starting. Count to 5. Turn the key off, and
then go straight to start. If that solves it, is simple fuel leakdown
which is easier to ignore than cure. Other than that, when is the
last time you had the vehicle serviced such as plugs, etc.?
