INTRODUCTION
Use this article to quickly find specifications related to servicing and on-vehicle adjustments. This article may be used for quick reference when you are familiar with proper adjustment procedures and only need a specification.
CAPACITIES
| Application | Cold Crank Amp @ 0°F (-18°C) | Reserve Minutes |
|---|
| 2.5L (VIN E) | 525 | 90 |
| 2.8L (VIN R) | 525 | 90 |
| 3.1L (VIN D) | 525 | 90 |
| 4.3L (VIN Z) |
| Standard | 525 | 90 |
| Heavy Duty | 630 | 115 |
| 5.0L (VIN H) |
| Standard | 430 | 90 |
| Heavy Duty | 525 | 90 |
| 5.7L (VIN K) |
| Standard | 525 | 90 |
| Heavy Duty | 630 | 115 |
| 6.2L (VIN C & J) | 570 | 90 |
| 7.4L (VIN N) | 630 | 115 |
| Application | (1) Quantity - Qts. (L) |
|---|
| Crankcase |
| 2.5L (VIN E) | (2) 3.0 (2.8) |
| 2.8L (VIN R) | (2) 4.0 (3.8) |
| 3.1L (VIN D) | (2) 4.0 (3.8) |
| 4.3L (VIN Z) (3) | (2) 4.0 (3.8) |
| 5.0L (VIN H) | (2) 4.0 (3.8) |
| 5.7L (VIN K) | (2) 4.0 (3.8) |
| 6.2L (VIN C & J) | 7.0 (6.6) |
| 7.4L (VIN N) | (2) 6.0 (5.7) |
| Cooling System (Includes Heater) (4) |
| 2.5L (VIN E) | 11.5 (11.0) |
| 2.8L (VIN R) | 10.5 (10.0) |
| 3.1L (VIN D) | 13.0 (12.3) |
| 4.3L (VIN Z) |
| "C" & "K" Series | 10.9 (10.3) |
| Other Models | 13.5 (12.8) |
| 5.0L (VIN H) | 17.0 (16.0) |
| 5.7L (VIN K) | 17.0 (16.0) |
| 6.2L (VIN C & J) | 25.0 (23.5) |
| 7.4L (VIN N) | 23.0 (22.0) |
| Automatic Transaxle (Dexron-II) (5) |
| 3.1L (VIN D) | 4.0 (3.8) |
| Automatic Transmission (Dexron-II) (5) |
| 2.5L (VIN E) | 5.0 (4.7) |
| 2.8L (VIN R) | 5.0 (4.7) |
| 4.3L (VIN Z) | 5.0 (4.7) |
| V8 Engines |
| THM 400 | 4.2 (4.0) |
| THM 700 | 5.0 (4.7) |
| Manual Transmission |
| 2.5L (VIN E) | (6) 2.2 (2.0) |
| 2.8L (VIN R) | (6) 2.2 (2.0) |
| 4.3L (VIN Z) | (6) 2.2 (2.0) |
| V8 Engines |
| 4-Speed (117 mm) | (7) 4.2 (4.0) |
| 5-Speed (85 mm) | (8) 1.8 (1.7) |
| 5-Speed (109 mm) | (7) 4.2 (4.0) |
| (1) Fluid capacities listed are approximate. Always fill to FULL mark. (2) Does not include oil filter capacity. (3) Use of synthetic 10W-30 motor oil is required on Turbo models. (4) Add 3 qts. (2.8L) coolant for models equipped with rear heater. (5) Drain and refill capacity only. Does not include torque converter. (6) Dexron-II. (7) SAE 80W-90. (8) Manual Transmission Fluid (12345349 or 1052931). |
| (1) | Fluid capacities listed are approximate. Always fill to FULL mark. |
| (2) | Does not include oil filter capacity. |
| (3) | Use of synthetic 10W-30 motor oil is required on Turbo models. |
| (4) | Add 3 qts. (2.8L) coolant for models equipped with rear heater. |
| (5) | Drain and refill capacity only. Does not include torque converter. |
| (8) | Manual Transmission Fluid (12345349 or 1052931). |
SERVICE INTERVALS & SPECIFICATIONS
| Component | Interval (Miles) |
|---|
| Air Filter | 30,000 |
| Coolant | 30,000 |
| Fuel Filter | (1) 60,000 |
| Oil & Filter | (2) 7500 |
| Spark Plugs | 30,000 |
| (1) On diesel engines, replace every 30,000 miles. (2) On diesel engines, replace every 5000 miles. |
| (1) | On diesel engines, replace every 30,000 miles. |
| (2) | On diesel engines, replace every 5000 miles. |
DRIVE BELT TENSION
| Application | (1) Tension - Lbs. (kg) |
|---|
| 2.5L, 2.8L & 3.1L | (1) |
| 4.3L, 5.0L & 5.7L |
| New Belt | 135 (61.2) |
| Used Belt | 90 (40.8) |
| 6.2L Diesel |
| New Belt | 146 (66.2) |
| Used Belt | 67 (30.4) |
| 7.4L |
| New Belt | 129.4-140.6 (58.7-63.8) |
| Used Belt | 84.4-95.6 (38.3-43.4) |
| (1) Serpentine belt tension is maintained automatically by a spring-tensioned idler pulley. No adjustment is necessary. |
| (1) | Serpentine belt tension is maintained automatically by a spring-tensioned idler pulley. No adjustment is necessary. |
ENGINE COMPRESSION
| Application | Compression Ratio |
|---|
| 2.5L (VIN E) | 8.3:1 |
| 2.8L (VIN R) | 8.9:1 |
| 3.1L (VIN D) | 8.9:1 |
| 4.3L (VIN Z) | (1) 9.3:1 |
| 5.0L (VIN H) | 9.3:1 |
| 5.7L (VIN K) | (2) 9.1:1 |
| 6.2L Diesel (VIN C & J) | 21.3:1 |
| 7.4L (VIN N) | 7.9:1 |
| (1) 8.6:1 on Turbo & heavy duty. (2) 8.3:1 on vehicles over 8500 lbs. GVW. |
| (1) | 8.6:1 on Turbo & heavy duty. |
| (2) | 8.3:1 on vehicles over 8500 lbs. GVW. |
COMPRESSION SPECIFICATIONS
VALVE CLEARANCE
Note. All models are equipped with hydraulic lifters. No adjustments are required.
IGNITION COIL
| Application | Ohms |
|---|
| All Models | 500-1500 |
HIGH TENSION WIRE RESISTANCE
| Application | Ohms |
|---|
| All Models | 30,000 Maximum |
HIGH TENSION WIRE RESISTANCE
SPARK PLUGS
| Application | AC |
|---|
| 2.5L (VIN E) | R43TS6 |
| 2.8L (VIN R) | R43TSK |
| 3.1L (VIN D) | R43TS |
| 4.3L (VIN Z) |
| Non-Turbo | CR43TS |
| Turbo | CR42TS |
| 5.0L (VIN H) | CR43TS |
| 5.7L (VIN K) | CR43TS |
| 7.4L (VIN N) | CR43TS |
| Application | Gap: In. (mm) | Torque: Ft. Lbs. (N.m) |
|---|
| 2.5L (VIN E) | .060 (1.52) | 17 (23) |
| 2.8L (VIN R) | .045 (1.14) | 22 (30) |
| 3.1L (VIN D) | .045 (1.14) | 18 (24) |
| 4.3L (VIN Z) |
| Non-Turbo | .035 (0.89) | 22 (30) |
| Turbo | .045 (1.14) | 11 (15) |
| 5.0L (VIN H) | .035 (0.89) | 22 (30) |
| 5.7L (VIN K) | .035 (0.89) | 22 (30) |
| 7.4L (VIN N) | .035 (0.89) | 22 (30) |
SPARK PLUG SPECIFICATIONS
Firing Order & Timing Marks (2.5L). Scheme 1
Scheme 1: Firing Order & Timing Marks (2.5L)
Firing Order & Timing Marks (2.8L). Scheme 2
Scheme 2: Firing Order & Timing Marks (2.8L)
Firing Order & Timing Marks (3.1L). Scheme 3
Scheme 3: Firing Order & Timing Marks (3.1L)
Firing Order & Timing Marks (4.3L). Scheme 4
Scheme 4: Firing Order & Timing Marks (4.3L)
Firing Order & Timing Marks (5.0L, 5.7L & 7.4L). Scheme 5
Scheme 5: Firing Order & Timing Marks (5.0L, 5.7L & 7.4L)
Firing Order (6.2L Diesel). Scheme 6
Scheme 6: Firing Order (6.2L Diesel)
IGNITION TIMING
Note. For timing procedures, see appropriate ADJUSTMENTS article in this section.
| Application | (1) Man. Trans. | (2) Auto. Trans. |
|---|
| 2.5L (VIN E) | 8 @ Idle | 8 @ Idle |
| 2.8L (VIN R) | 10 @ Idle | 10 @ Idle |
| 3.1L (VIN D) | 10 @ Idle | 10 @ Idle |
| 4.3L (VIN Z) | 0 @ Idle | 0 @ Idle |
| 5.0L (VIN H) | 0 @ Idle | 0 @ Idle |
| 5.7L (VIN K) | 0 @ Idle | 0 @ Idle |
| 7.4L (VIN N) | 4 @ Idle | 4 @ Idle |
| (1) With transmission in Neutral. (2) With transmission in Neutral or Park. |
| (1) | With transmission in Neutral. |
| (2) | With transmission in Neutral or Park. |
IGNITION TIMING (Degrees BTDC @ RPM)
FUEL PUMP
| Application | Psi (kg/cm 2 ) |
|---|
| 4.3L Turbo (VIN Z) | 35-38 (2.5-2.7) |
| 6.2L Diesel (VIN C & J) | 6-9 (.42-.63) |
| All Others | 9-13 (.63-.91) |
INJECTOR RESISTANCE
| Application | (1) Resistance (Ohms) |
|---|
| 3.1L (VIN D) | 1.2 |
| 4.3L Turbo (VIN Z) | 2.0 |
| All Others | 1.3 |
| (1) Injector resistance specification is at 140°F (60°C). |
| (1) | Injector resistance specification is at 140°F (60°C). |
INJECTOR RESISTANCE SPECIFICATIONS
IDLE SPEED & MIXTURE
Note. Idle mixture on fuel injected models is controlled by the Electronic Control Module (ECM) and is not adjustable.
THROTTLE POSITION SENSOR (TPS)
Note. TPS is adjustable only on 2.8L (VIN R) and 6.2L Diesel engines. For further testing, see the appropriate articles below
- «TESTS W/CODES - DIESEL»(ref-10254)
- «TESTS W/CODES - GASOLINE»(/gmc/sonoma-syclone/1991-1992/remont/testing-diagnostics/#engine-controls-tests-wcodes-gasoline)
| Application | (1) Voltage |
|---|
| 2.8L (VIN R) | .42-.45 |
| 6.2L Diesel (VIN C & J) | (2) .63 |
| (1) At idle RPM or closed throttle. (2) This is TPS voltage ratio. For adjustment procedure, see ADJUSTMENTS article in this section. |
| (1) | At idle RPM or closed throttle. |
| (2) | This is TPS voltage ratio. For adjustment procedure, see ADJUSTMENTS article in this section. |
