Electra Estate Wagon V8-350 5.7L DSL VIN N FI (1984)
Diesel MFI Pump: Technical Service Bulletins
Checking Injection Pump Housing Fuel Pressure - Except California
Tools Required:
J-28552 Gage or any accurate 0-105 kPa (0-15 psi) Pressure Gage J-34151 Housing Pressure Adapter J-29657 Manifold Screen Covers - V-6 Diesel
Engine J-26925 Tachometer J-26996-1 Air Crossover Cover J-26996-10 Manifold Screen Covers - V-8 Diesel Engine
Figures 3 and 4 are diagnostic flow charts for checking housing pressure to determine if it is correct and also what to do if it isn't. Next to some "Boxes"
in the chart are footnotes ("A", "B", etc.). These footnotes are listed below. This was done to reduce "clutter" in the chart. Refer to the footnotes as
required.
"A"
1.
Block the drive wheels and firmly apply the parking brake. Shift the transmission/transaxle to "P" (Park).
2.
Start the engine and let run at idle until fully warmed up. Then shut off the engine.
3.
Remove the air cleaner and install air crossover cover J-26996-1.
4.
Disconnect the fuel return pipe from the pump.
5.
Remove the return line connector and housing pressure regulator as an assembly.
6.
Install adapter J-34151 in the pump cover.
7.
Install the return line connector and housing pressure regulator into J-34151 and connect the return pipe to the return line connector.
8.
Attach a pressure gage to J-34151.
9.
Install J-26925 tachometer.
10.
Disconnect the HPAA lead.
11.
Start the engine. Inspect for fuel leaks and correct them.
12.
Increase the idle speed to 1,000 rpm and note pressure.
"B"
1.
Shut off the engine.
2.
Remove the line fitting from the pressure regulator.
3.
Insert a 1/8" HEX key into the pressure regulator (Figure 2). Rotate the adjustment screw clockwise to increase pressure, counterclockwise to
decrease pressure. Adjust the pressure regulator to obtain 68.95 kPa (10 psi). One turn of the screw will change housing pressure 22 kPa (3.2 psi).
4.
Check and reset timing. See "Checking and/or Adjusting Timing," in Section 6C5 of the 1984 Chassis Service Manual.
"C"
When housing pressure is this low, the HPCA pressure regulator check ball is either not seated or partially seated because of a fault in the pressure
regulator.
1.
Remove the pressure regulator from the adapter.
2.
Using a maximum of 207 kPa (30 psi) of air pressure, blow through the regulator from the pump side first and then from the outlet side. The check
ball should seat when blowing through the outlet side.
CAUTION: Safety glasses must be worn when using compressed air to avoid injury to the eyes.
3.
Replace the pressure regulator if it is faulty. If debris is found in the regulator, remove the injection pump cover to determine the source.
"D"
1.
Disconnect the HPAA solenoid at the pump to HPAA pipe.
