No rail pressure at all? 5.9 cr
 

Just out a motor back together with a set of dual pumps that the truck drove into the shop with , set of injectors with only a few passes on them. Went to start truck and have 15psi at pump inlet but zero rail. Bumps to 100 pounds every once in awhile. ,thats it supply flow is plenty. Have checked returns on each pump and back of head along with prv and its dry ,changed one cp3 out and ran it as a single in stock location , makes no difference with fca plugged in or not amf have swapped for new ones even . Any ideas?

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Have also tried 3 other rail sensors and one was bad showing 27,400 all the time and still nothing ,

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Sounds like the FCA went bad.

See this thread, mine went bad and did the exact opposite you are seeing. Depending on the wire that went bad it could see the need for more rail pressure or less rail pressure.

P088 and P0251 - Competition Diesel.Com - Bringing The BEST Together

Swapped them out with new fca on both pump and with them unplugged i should be seeing max rail,, but nothing still

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Have you checked the wiring? If the wiring is bad, which mine was, it will send the wrong signal to the computer. Mine was sending no signal, yours might be sending full signal. Ohm out the wires and see what each one says, what they should say is on the thread that I linked.

Ok will try it

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Checked plug on rail sensor. Showing 5v on one. Ground on other side and .5 on center , .53 is all i see while cranking

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28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM)/Diagnosis and Testing
P0251-CP3 PUMP REGULATOR CONTROL
For a complete wiring diagram Refer to the Wiring Information.

When Monitored:
When the ignition is on.

Set Condition:
The ECM detects a discrepancy between the PWM supplied to the Electronic Fuel Control Actuator and the PWM returned from the Electronic Fuel Control Actuator.


Possible Causes
FUEL PUMP
(K604) FUEL CONTROL ACTUATOR DRIVER OPEN
(K65) RETURN CIRCUIT OPEN FROM FCA TO ECM
(K604) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO EXTERNAL VOLTAGE
(K65) FUEL CONTROL ACTUATOR RETURN CIRCUIT SHORTED TO EXTERNAL VOLTAGE
(K65) FCA RETURN CIRCUIT SHORTED TO (K604) FCA DRIVER CIRCUIT
(K604) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO GROUND
(K604) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO ANOTHER CIRCUIT
(K65) FUEL CONTROL ACTUATOR RETURN CIRCUIT SHORTED TO ANOTHER CIRCUIT
INTERMITTENT CONDITION
ECM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)



1.FUEL PUMP


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1. Ignition on, engine not running.
2. Disconnect the Fuel Control Actuator (FCA) harness connector.
3. Connect an incandescent test light across the Fuel Control Actuator driver circuit and the Fuel Control Actuator return circuit at the fuel control actuator harness connector.
4. Observe the test light.
5. The ECM will perform a self test of the circuit which should momentarily flash the test light brightly, one time, approximately 20 seconds after being connected.


NOTE: Check connectors - Clean/repair as necessary.

NOTE: Compare test light brightness to that of a direct connection to the battery.


Did the light flash brightly?

Yes

Replace the Fuel Pump.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)

No

Go To 2




2.(K604) FUEL CONTROL ACTUATOR DRIVER OPEN


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1. Turn the ignition off.
2. Disconnect the ECM harness connectors.


NOTE: Check connectors - Clean/repair as necessary.
3. Measure the resistance of the FCA driver circuit between the electronic fuel control actuator harness connector and the ECM harness connector.


Is the resistance less than 10 Ohms?

Yes

Go To 3

No

Repair the (K604) Fuel Control Actuator Driver circuit OPEN.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)




3.(K65) RETURN CIRCUIT OPEN


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1. Measure the resistance of the (K65) return circuit between the FCA harness connector and the ECM harness connector.


Is the resistance less than 10 Ohms?

Yes

Go To 4

No

Repair or replace the engine wiring harness.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)




4.(K604) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO EXTERNAL VOLTAGE


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1. Measure the voltage between the (K604) FCA driver circuit in the FCA harness connector and battery negative.


Is the voltage greater than 1 volts?

Yes

Repair the (K604) FCA driver circuit shorted to external voltage.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)

No

Go To 5




5.(K65) FUEL CONTROL ACTUATOR RETURN CIRCUIT SHORTED TO EXTERNAL VOLTAGE


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1. Measure the voltage between the (K65) FCA return circuit in the FCA harness connector and battery negative.


Is the voltage greater than 1 volts?

Yes

Repair the (K65) FCA return circuit shorted to external voltage.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)

No

Go To 6




6.(K65) FCA RETURN CIRCUIT SHORTED TO (K604) FCA DRIVER CIRCUIT


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1. Measure the Resistance between the return circuit in the FCA harness connector and Driver circuit.


Is the resistance less than 10 Ohms?

Yes

Repair the (K65) FCA Return circuit shorted to (K604) FCA Driver circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)

No

Go To 7




7.(K604) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO GROUND


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1. Measure the resistance between the (K604) FCA driver circuit in the FCA harness connector and battery negative.


Is the resistance less than 10 Ohms?

Yes

Repair the (K604) FCA driver circuit shorted to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)

No

Go To 8




8.(K604) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO ANOTHER CIRCUIT


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1. Measure the resistance between the (K604) FCA driver circuit in the ECM harness connector and all other circuits in the ECM connectors.


Is the resistance less than 10 Ohms?

No

Go To 9

Yes

Repair the (K604) FCA driver circuit shorted to another circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)




9.(K65) FUEL CONTROL ACTUATOR RETURN CIRCUIT SHORTED TO ANOTHER CIRCUIT


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1. Measure the resistance between the (K65) FCA Return circuit in the ECM harness connector and all other circuits in the ECM connectors.`


Is the resistance less than 10 Ohms?

No

Go To 10

Yes

Repair the (K65) FCA Return circuit shorted to another circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)




10.ECM


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1. Reconnect the ECM harness connectors.
2. Ignition on, engine not running.
3. Disconnect the Electronic Fuel Control Actuator connector.
4. Connect an incandescent test light across the Fuel Control Actuator driver pin and the Fuel Control Actuator return wire at the fuel control actuator connector.
5. Observe the test light.
6. The ECM will perform a self test of the circuit which should momentarily flash the test light brightly, one time, approximately 20 seconds after being connected.


NOTE: Compare test light brightness to that of a direct connection to the battery.


Did the light flash brightly?

Yes

Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)

No

Replace the ECM.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)

28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM)/Diagnosis and Testing
P0088-FUEL RAIL PRESSURE SIGNAL IS ABOVE MAX LIMIT




For a complete wiring diagram Refer to the Wiring Information.

When Monitored:
Engine running.

Set Condition:
Fuel pressure is above a calibrated value for a calibrated amount of time.


Possible Causes
FUEL CONTROL ACTUATOR (FCA)
FUEL PRESSURE SENSOR
INTERMITTENT CONDITION

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)



1.Fuel Pressure Sensor


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1. Using the scan tool, compare the scan tool reading for fuel pressure set point to the scan tool reading for actual fuel pressure.


Does the actual fuel pressure correlate with the fuel pressure setpoint while operating the engine over various operating conditions?

Yes

Go To 2

No

Check the electrical connector of the Fuel Control Actuator, if the connection is tight, replace the fuel control actuator.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)




2.FUEL PUMP


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1. Turn the ignition on.
2. Disconnect the Electronic Fuel Control Actuator connector.
3. Connect an incandescent test light across the Fuel Control Actuator driver pin and the Fuel Control Actuator return wire at the fuel control actuator connector.
4. Observe the test light.
5. The ECM will perform a self test of the circuit which should momentarily flash the test light brightly, one time, approximately 20 seconds after being connected.


NOTE: Compare test light brightness to that of a direct connection to the battery.
6.


Did the light flash brightly?

Yes

Replace the fuel pump.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)

No

Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)

Those two should help you. If you have access to a fancy scan tool that will run diagnosis it will save those step and is how I found my issue.

I dont believe its a eletrical issue, as after cranking you can pull a injection line and they will ne empty still

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Guess you need to send the pumps out to be checked then.

So we got it running ,it was at my fault thay it didn't build rail

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What was it?

Misaligned feed tube because of a sealing washer on injector gone missing ,not proud of it

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Always check return flow on a CR

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