VALVE ARRANGEMENT
- I-E-I-E-I-E-I-E (Left Bank, Front-to-Rear).
- E-I-E-I-E-I-E-I (Right Bank, Front-to-Rear).
VALVE CLEARANCE
All engines use hydraulic lifters. No adjustment is required.
GLOW PLUGS
Glow plugs are small 6-volt heaters operated by the electronic controller/glow plug relay assembly. Assembly is located at rear of left cylinder head.
Glow plugs cycle on and off, powered by 12 volts to give rapid heating. Glow plug light on dash should illuminate as plugs cycle on and off. Glow plugs cycle for approximately 25 seconds with ignition on, whether engine starts or not.
On and off cycling varies with system voltage and temperature. A glow plug inhibit switch opens above 125°F (52°C) to prevent glow plug operation. Switch is mounted on coolant crossover passage, at front of engine.
6.2L Diesel Engine Firing Order. Scheme 6
INJECTION PUMP TIMING
- All 6.2L engines are timed both statically and dynamically at assembly. The dynamic timing marks are half circles. Static timing marks are straight lines. Whenever possible, use dynamic timing marks to adjust injection pump timing. If a replacement pump is to be used, adjust injection timing using static marks.
- Check alignment of injection pump timing marks on top of engine front cover and injection pump flange. If timing marks are not aligned, loosen 3 retaining nuts, and align marks on injection pump with marks on front cover. Tighten nuts to 30 ft. lbs. (41 N.m) and adjust throttle linkage.
HOT (SLOW) IDLE RPM
Set parking brake and block drive wheels. Warm engine to normal operating temperature and install Tachometer (J-26925). Adjust curb idle speed screw on pump to obtain curb idle speed. (Scheme 7) See HOT (SLOW) IDLE RPM SPECIFICATIONS table.
| Application | Idle RPM |
|---|---|
| 6.2L | 650 |
HOT (SLOW) IDLE RPM SPECIFICATIONS
COLD (FAST) IDLE RPM
- Set parking brake and block drive wheels. Warm engine to normal operating temperature and install Tachometer (J-26925). Remove connector from fast idle solenoid. (Scheme 7)
- Connect jumper wire from battery positive terminal to solenoid terminal to energize solenoid. Open throttle to ensure plunger is fully extended.
- Adjust fast idle speed by turning plunger hex head. See «COLD (FAST) IDLE RPM SPECIFICATIONS»(/gmc/magnavan-g3500/1985-1993/remont/adjustments/#tune-up-diesel) table. Turn engine off. Remove jumper wire and test equipment. Install fast idle solenoid connector.
| Application | RPM |
|---|---|
| 6.2L | 800 |
COLD (FAST) IDLE RPM SPECIFICATIONS
Scheme 7
6.2L Engine W/Heavy Duty Emissions & Automatic Transmission
- Loosen Vacuum Regulator Valve (VRV) so that it is free to rotate on fuel injection pump. Connect vacuum pump and apply 18-21 in. Hg vacuum to bottom port. (Scheme 8)
- Attach vacuum gauge to top vacuum port. Install.646" (16.41 mm) thick Gauge Block (J-33043-2) between gauge boss on injection pump and wide open throttle valve stop screw on throttle lever (switch on position).
- Rotate throttle shaft and hold it against gauge block. Slowly rotate vacuum regulator valve clockwise (facing valve) until vacuum gauge reads 11-12 in. Hg. Hold valve body in this position, and tighten mounting screws to 54 INCH lbs. (6 N.m). NOTE: Vacuum regulator valve must be set while rotating valve body in a clockwise direction only.
- Check adjustment by releasing throttle shaft, allowing it to return to idle stop position. Rotate throttle shaft back against gauge block and determine if vacuum gauge reading is 11-12 in. Hg. If vacuum reading is outside specifications, reset valve.
- With VRV adjustment set, confirm detent switch point by reading resistance between ignition terminal (Pink/Black wire) and detent terminal (Orange wire). Insert Detent Switch Gauge (J-36142) between wide open throttle stop pin and wide open stop screw on throttle lever. (Scheme 8)
- Rotate throttle lever against gauge. Ohmmeter should show no continuity. Release throttle lever and remove gauge. Slowly rotate throttle to wide open throttle.
- With lever stop screw touching pump stop pin, check switch continuity. Ohmmeter should show 0-1 ohms continuity just before throttle reaches wide open throttle position. If not, repeat entire test procedure.
Scheme 8
EMISSION CONTROL
For information on emission control systems, see EMISSION CONTROL SYSTEMS section.
FUEL SYSTEM
| Application | Model |
|---|---|
| 6.2L | Stanadyne Diesel Injection |
DIESEL FUEL INJECTION
BATTERIES
All V8 diesel vehicles use two 12-volt, negative ground, sealed-top Delco batteries. Batteries are located on each side of engine compartment and are wired in parallel.
| Application | Cold Crank Amps @ 0°F (-18°C) | Reserve Capacity Minutes |
|---|---|---|
| All Models | 570 | 90 |
BATTERY SPECIFICATIONS
SERVICE INTERVALS
| Component | Interval (Miles) | |
|---|---|---|
| Air Cleaner Element | ||
| Light Duty Emissions | 30,000 | |
| Heavy Duty Emissions | 15,000 | |
| Coolant | 30,000 | |
| Oil & Filter | 5000 | |
REPLACEMENT INTERVALS
BELT ADJUSTMENT
Note. Tension in Lbs. (Kg) Using Strand Tension Gauge.
| Application | New Belt | (2) Used Belt | |
|---|---|---|---|
| "G", "P", "R" & "V" | |||
| A/C | 169 (77) | 90 (41) | |
| Alternator | 146 (66) | 67 (30) | |
| Power Steering | 146 (66) | 67 (30) | |
| (1) All "C" & "K" series trucks use a single serpentine belt. Proper belt tension is maintained by an automatic tensioner. (2) Any belt in operation 10 minutes or more. | |||
| (1) | All "C" & "K" series trucks use a single serpentine belt. Proper belt tension is maintained by an automatic tensioner. |
| (2) | Any belt in operation 10 minutes or more. |
BELT ADJUSTMENT (1)
CAPACITIES
| Application | Qts. (L) |
|---|---|
| "G" Series | 25.5 (24.1) |
| All Others | 25 (23.7) |
COOLING SYSTEM CAPACITIES
| Application | Qts. (L) |
|---|---|
| All Models | 7.0 (6.6) |
ENGINE OIL CAPACITIES
| Application | Qts. (L) | ||
|---|---|---|---|
| Automatic Transmission (Dexron II) | |||
| THM 400/475 | |||
| Overhaul | 10.5 (10.0) | ||
| Refill | 4.2 (4.0) | ||
| THM 700-R4 | |||
| Overhaul | 11.5 (10.9) | ||
| Refill | 5.0 (4.7) | ||
| Manual Transmission | |||
| 4-Speed (M20 - SAE 80W/90) | 4.2 (4.0) | ||
| 4-Speed Overdrive (MY6 - Dexron II) | 4.2 (4.0) | ||
| Front Axle (SAE 80W-90 GL5) | |||
| 8 1/2" Ring Gear (K15/25 & V10-20/15-25) | 1.8 (1.7) | ||
| 9 3/4" Ring Gear (Dana - K35 & V20/25) | 2.3 (2.2) | ||
| Rear Axle (SAE 80W-90 GL5) | |||
| 8 1/2" Ring Gear | (1) 4.2 (2.0) | ||
| 9 1/2" Ring Gear | (1) 5.5 (2.6) | ||
| 9 3/4" Ring Gear (Dana) | (1) 5.5 (2.6) | ||
| 10 1/2" Ring Gear | (1) 5.5 (2.6) | ||
| 12" Ring Gear (Rockwell) | (1) 14.0 (6.6) | ||
| Transfer Case (Dexron II) | |||
| Borg-Warner 1370 | 2.8 (2.6) | ||
| New Process 205 | (1) 5.2 (2.5) | ||
| New Process 241 | (1) 2.8 (1.3) | ||
| (1) Capacities listed are in pints (Liters). | |||
| (1) | Capacities listed are in pints (Liters). |
AXLE, TRANSFER CASE & TRANSMISSION CAPACITIES
| Application | Ozs. | |
|---|---|---|
| "C" & "K" Series | 40 | |
| "G" Series | ||
| Front (C60) System | 56 | |
| Rear (C69) System | 72 | |
| "R" & "V" Series | ||
| Front (C60) System | 52 | |
| Rear (C69) System | 84 | |
A/C SYSTEM REFRIGERANT CAPACITIES
See also:
• HOT (SLOW) IDLE RPM SPECIFICATIONS