Monitor ICP While Cranking

Purpose:
To determine if the injection control system can supply enough injection control pressure to sustain starting.

Recommended Procedure:
Connect OBDII Scan Tool to the data link connector (DLC) under the dash. Access ICP PID on Scan tool menu nd monitor ICP reading while cranking the engine.

Note: CMP signal is required before injection control pressure is allowed above 400 psi.

If value does not meet the minimum specification, the injectors are not being enabled by the PCM because of insufficient pressure.

Possible Causes:

  • Injection control pressure system leak.
  • Oil reservoir level low.
  • IPR failure.
  • Faulty high pressure pump.


Injection Control Pressure Leak Test 

Removing the ICP sensor and inspecting the level in the oil rail will determine if oil is being supplied to the rail. Removing the inspection plug in the top of the reservoir will help determine if the reservoir is full. A reservoir that drains back after the engine has not been operated for a long period of time can cause a hard start condition.

Purpose:
Isolate the cause of low injection control pressure.

Recommended Procedure:

Right Cylinder Head Check

Remove the high pressure hose from the right cylinder head and cover the fitting on the cylinder head with the appropriate cap from the Fuel/Oil/Turbo Protector Cap Set T94T-9395-AH. Install the plug from the Oil High Pressure Leakage Test Adapter Set D94T-6600-A into the high pressure hose to block it off. Connect the ICP/EBP Adapter Cable D94T-50-A to the ICP sensor. Connect a DVOM between signal return and ICP signal wires on the ICP/EBP Adapter Cable D94T-50-A. Crank the engine and monitor the signal. The DVOM should read 1 to 4 volts.

 CAUTION: The engine may start!

If the engine starts or if injection control pressure is now within specification, the injection control pressure leak has been isolated to the right cylinder head. Inspect the fuel to see if oil is in the fuel. If no oil is present in the fuel, remove the valve cover, crank the engine and inspect the injector body and injector bore area for leakage.

 CAUTION: Oil is under high pressure!

Left Cylinder Head Check

Remove the cap and plug, then reinstall the high pressure hose to the right cylinder head. Remove the high pressure hose from the left cylinder head and cover the fitting on the cylinder head with the appropriate cap from the Fuel/Oil/Turbo Protector Cap Set T94T-9395-AH. Install the ICP adapter from the Oil High Pressure Leakage Test Adapter Set D94T-6600-A into the high pressure hose. Remove the ICP sensor and install the sensor in the end of the ICP adapter. Connect the ICP/EBP Adapter Cable D94T-50-A to the ICP sensor. Connect a DVOM between the signal return and ICP signal wires of the ICP/EBP Adapter Cable D94T-50-A. Crank the engine and monitor the signal. The DVOM should read 1 to 4 volts.

 CAUTION: The engine may start!

If the engine starts or if injection control pressure is now within specification, the injection control pressure leak has been isolated to the left cylinder head.

IPR and High Pressure Pump Test

If injection control pressure is still low after ruling out both cylinder heads as the source of injection control pressure leakage, perform the following steps to isolate the cause.

  • Leave the ICP sensor and ICP adapter connected to the left high pressure hose.
  • Remove the high pressure hose from the right cylinder head and cover the fitting on the cylinder head with the appropriate cap from the Fuel/Oil/Turbo Protector Cap Set T94T-9395-AH.
  • Install the plug from the Oil High Pressure Leakage Test Adapter Set D94T-6600-A into the high pressure hose to block it off.
  • With the high pressure pump effectively deadheaded, crank the engine and monitor the signal.

If injection control pressure is not within specification, replace the Injection Pressure Regulator (IPR) with a known good IPR and retest. If a low pressure condition still exists, the problem is most likely with the high pressure pump or the high pressure pump drive gear.

Tools Required:

  • Fuel/Oil/Turbo Protector Cap Set T94T-9395-AH
  • ICP/EBP Adapter Cable D94T-50-A
  • Oil High Pressure Leakage Test Adapter Set D94T-6600-A
  • Rotunda Digital Volt-Ohm Multimeter (DVOM) 105-00050 or equivalent
  • 1/4-inch drive ratchet or breaker bar to remove inspection plug