Hi folks,

I am having problems with my 2006 Liberty CRD (99k miles). The engine will not build rail pressure. This may be related to a previous issue where the engine suddenly died but would run when primed. I installed the Sasquatch lift pump & engine started up and ran at idle. When I tried to increase engine speed, the engine died and hasn't run since. I have confirmed rail pressure is not building as it should. What I’ve done:

1. Bleed line at each injector (several times),
2. Removed return line at regulating valve on rail and confirmed NO fuel flow during cranking
3. Confirmed no fuel through injector return line
4. Installed temporary 10k digital gauge at #1 injector port and cranked engine, no pressure build (<100 PSIG).
5. Cracked line from pump and confirmed fuel pulses from pump, although hard to quantify amount.
6. Replaced fuel solenoid valve on back of CP3 pump. No change.
7. New filter head recently installed.

Lift pump is working. I crack filter head outlet connection and turn key on, fuel flows. One thing that seems unusual is the in-tank pump will flow through to the injector rail. I can crack inlet line from pump at rail and turn key on and fuel will flow without cranking.

I am reticent to replace the CP3 pump as I have read in many places that it rarely fails. I am running out of options, however. Does anyone have any suggestions? If the CP3 pump needs replacing, is there any positive experience using a rebuilt pump?

Thx - JBA

Maybe this could be of help? Each item must be ruled out individually to determine the exact cause of a no start condition due to improper fuel pressure.

FUEL SYSTEM DIAGNOSIS
Items that can cause a “No Start” condition:

1. **Air in fuel**, leak on suction supply to CP3, stopped up fuel filter, etc...(Inadequate fuel supply to CP3 will prevent injection pump from supplying proper fuel pressure to fuel rail)
2. Weak battery, low voltage. (voltage level dropping below minimum required voltage for ECM to function properly. ~8 volts or less at ECM)
3. Crankshaft Position Sensor faulty (loss of signal) (If no CPS signal is present, the ECM will not allow engine to start/run)
4. Camshaft Position Sensor faulty (loss of signal)
5. Cascade/Overflow Valve (on top of CP3) Regulates lubrication to internal parts of the injection pump and regulates the fuel pressure to the fuel quantity solenoid valve on the back of CP3 injection pump. Also, controls the amount of fuel being returned to the fuel tank via the fuel return line.
6. Fuel Pressure Solenoid (on end of fuel rail) aka: Fuel Rail Pressure Control Valve (The fuel pressure solenoid controls and maintains the rail pressure constant along with a control current provided by the engine control module (ECM)) Leaking fuel pressure solenoid (on end of fuel rail). There should be no fuel coming out of the solenoid return line while cranking the engine. Perform the fuel rail pressure solenoid leak quantity test to determine if it is faulty. If the injectors check good, the fuel pressure solenoid should hold 870-1450 psi when unplugged during cranking.
7. Fuel Rail Pressure Sensor (on side of fuel rail) A faulty pressure sensor could be giving the ECM incorrect pressure information and prevent the engine from starting.
8. Fuel Injector (leaking by not allowing fuel rail pressure to build up to required operating pressure) Monitor rail pressure and see if you have over 3600 PSI, or 1.0 volt, during cranking. If not, one or more internally leaking injectors can cause a hard start. See injector section in FSM for further diagnostics. No smoke from the tailpipe after about 10 seconds of cranking means no fuel is getting into the cylinders. Buy Genuine Bosch OE Injectors
9. Fuel Quantity Solenoid (on back of CP3) The Fuel Control Actuator solenoid valve is a pulse-width modulated valve that controls the amount of fuel sent or delayed to the high-pressure pump elements inside the high-pressure pump. If all of the above tests pass and rail pressure is still below spec, try unplugging the Fuel Quantity Control Valve (FCA) on the CP pump and see if the rail pressure increases, if not, the CP3 injection pump could be bad.

**No. 1 cause of No Start Condition!

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