Diesel Engine/Fuel System - Checklist/Diagnostic Charts
Number: 84-131
Section: 6C (VI)
Date: May, 1984
Subject: ENGINE AND FUEL SYSTEM CHECKLIST AND DIAGNOSTIC CHARTS - 6.2L DIESEL ENGINE
Model and Year: 1982-84 "C", "K", AND "P" TRUCK
AND 1983-84 "G" VAN
TO: ALL CHEVROLET DEALERS
The following checklist and diagnostic charts are provided as an aid to technicians for servicing the 6.2L diesel engine. Before removing the fuel injection pump from the engine, the Automotive Diesel Diagnostic Checklist should be completed. A copy of the checklist should accompany the pump when sent for repairs.
AUTOMOTIVE DIESEL DIAGNOSTIC CHECKLIST
Dealer Name_____________________________ Tel. No_________________________ Date_____________________________
Vehicle Make/Model__________________________ VIN_____________________________ Mileage
Vehicle Technician's Name__________________________________________________________
Pump Model No._____________________________ Serial No_____________________________
The following checks are to be performed by the vehicle service technician prior to removing the pump from the engine repairs to assure proper service and warranty consideration. and sending it to a Stanadyne repair agency. A copy of this completed form should accompany the pump when sent for
ENGINE CONDITION
Perform Diagnostic Checks in the Numerical Order Indicated After Each "Engine Condition"
[] Engine Will Not Start 1, 2, 12, 3, 5, 7, 4 [] White Exhaust Smoke 17, 6, 8, 3, 11, 10, 4
[] Engine Starts Hard, 1, 3, 12, 5, 6, 7, 10, 4 [] Engine Stalls 5, 11, 15, 12, 16
[] Rough Idle 5, 7, 3, 11, 8, 16, 10, 4 [] Lack of Power 13, 9, 8, 6, 11, 14, 10
[] Engine Misfires or Runs Rough 5, 8, 6, 11, 10, 7, 16, 12 [] Poor Fuel Economy 9, 8, 6, 11, 14, 10
[] Black Exhaust Smoke 9, 8, 6, 14, 10, 4 [] Fuel Leak (See Illustrations Below)
DIAGNOSTIC CHECKS
Prior to performing any diagnostic checks, ensure that vehicle
Yes No has sufficient clean, quality fuel in tank. Collect a sample of
[] [] Fuel OK fuel in a clear container and visually examine for cloudiness,
solid particles or water contamination.
Yes No Yes No
[] [] 1. Cranking Speed OK_____ [] [] 10. Nozzles Test OK on Pop Tester (Especially Seat
RPM___Cold RPM____Hot Leakage and Opening Pressure)______
[] [] 2. Fuel Shutoff Solenoid OK [] [] 11. Pump Housing Pressure OK (Note 3)
[] [] 3. Glow Plugs Operational Pressure____ per Maximum
[] [] 4. Compression Checked [] [] 12. Adequate Fuel Supply (Note 4)
[] [] 5. Return Fuel Free of Air Bubbles Pressure____per Volume____pints
[] [] 6. Timing OK (Note 1) [] [] 13. Full Throttle Travel
[] [] 7. Lines Bled [] [] 14. EGR/EPR Valves Functioning
[] [] 8. Advance Functioning (Note 2) [] [] 15. Continuous Voltage to Shutoff Solenoid
[] [] 9. Air Cleaner OK [] [] 16. Governor Flex. Ring Intact
[] [] 17. HPCA Solenoid Functioning
If Pump is Sent to Stanadyne Repair Agency Specify Type of Repair Requested____________________________________
CIRCLE LEAKAGE POINT:
CIRCLE LEAKAGE POINT
FIGURE 1 - DEPRESSING ROCKER LEVER:
Note 1 Check pump alignment marks and set to factory specifications.
Note 2 (See Figure 1) Depress rocker lever on side of pump. Engine sound and speed should change.
FIGURE 2 - CHECKING HOUSING PRESSURE (12 PSI MAX.):
Note 3 (See Figure 2) To check housing pressure, disconnect fuel return line, remove return line connector from top of pump and install gauge adapter. Reinstall return line connector to gouge adapter and reconnect fuel return line. Start engine. Housing pressure at
idle should be no more than 12 psi. If higher, correct restriction In fuel return line or replace connector.
FIGURE 3 - CHECKING SUPPLY PRESSURE (2 PSI MIN.):
Note 4 (See Figure 3) To check fuel supply pressure, install gauge between filter and injection pump inlet. Pressure at idle to be 2 psi minimum. To perform volume check, disconnect fuel supply line from filter inlet, add extension hose, and route to a graduated container that can hold at least 1 quart. Disconnect pink lead from electric fuel shutoff solenoid 15 on top of pump and crank for 15 seconds. Fuel pump should supply a minimum of 1/2 pint. If less, correct restriction in fuel supply system.
FIGURE 1 - DEPRESSING ROCKER LEVER:
Depressing Rocker Lever
Idling engine sound should change when lever is depressed. If it does not, pump should be removed and sent to an authorized agency for repairs.
Engine Diagnostic Chart:
ENGINE DIAGNOSTIC CHART
FUEL SYSTEM DIAGNOSTIC CHART:
FUEL SYSTEM DIAGNOSTIC CHART
FUEL SYSTEM NOZZLE DIAGNOSTIC CHART:
FUEL SYSTEM NOZZLE DIAGNOSTIC CHART
TIMING METERS
Diesel engine timing meters have the capability of checking engine timing and rpm. These meters can be used to perform diagnostic checks on the 6.2 liter diesel engine. The 6.2 liter engine's injection pump timing must be set to static specifications outlined in the Service Manual or appropriate Truck Service Bulletin.
TIMING METERS AND DIAGNOSTIC PROCEDURES
The timing meter's timing capability and tachometer can be used to check the injection pump's housing pressure cold advance and rocker arm mechanical light load advance functions for operation. These checks may indicate if the pump's advance solenoid, advance piston assembly and cam ring are functioning and not binding or seized.
PROCEDURE
1. Place the transmission selector in park, (neutral with manual transmission) apply the parking brake and block the wheels.
2. Start the engine and let idle until fully warmed up. Then shut off engine.
3. Clean any dirt from the engine probe holder (rpm counter) and crankshaft balancer rim.
4. Attach the timing meter, following manufacturer's instructions.
5. Start engine and adjust idle to 650 rpm. Note engine timing and rpm readings.
HOUSING PRESSURE COLD ADVANCE CHECK
Disconnect advance solenoid's terminal wire at the injection pump. Attach a jumper wire to the battery positive terminal and touch injection pump's advance solenoid terminal. Note engine timing and rpm readings.
When the advance is functioning properly, the engine's timing will advance approximately 3 to 5 degrees and rpm will increase when the solenoid is energized.
ROCKER ARM MECHANICAL LIGHT LOAD ADVANCE CHECK (FIGURE 1)
Using a ten-inch long screwdriver, push the injection pump's rocker arm (at lower end) towards injection pump. Note engine timing and rpm readings.
When the rocker arm mechanical light load advance is functioning properly, the engine's timing will retard approximately 3 to 5 degrees and rpm will decrease.
Injection pump removal is normally required to repair the pump's internal mechanical advance.
Engine rpm may require readjustment to emission label specifications when diagnostic procedures are completed.