Compression
Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. See engine analyzer manual for specific instructions.
| WARNING | DO NOT use ignition switch during compression tests. Use a remote starter to crank engine. Fuel injectors on many models are triggered by ignition switch during cranking mode, which can create a fire hazard or contaminate the engine's oiling system. |
| Application | Specification | ||
|---|---|---|---|
| Compression Ratio | |||
| Camry | 9.3:1 | ||
| Celica | |||
| Non-Turbo | 9.5:1 | ||
| Turbo | 8.8:1 | ||
| Corolla | |||
| 4A-FE | 9.5:1 | ||
| 4A-GE | 10.3:1 | ||
| MR2 | |||
| 2.0L | 8.8:1 | ||
| 2.2L | 9.5:1 | ||
| Previa | NA | ||
| Pickup, Tercel & 4Runner | 9.3:1 | ||
| Normal Compression Pressure | |||
| Celica Turbo | 164 psi (11.5 kg/cm 2 ) | ||
| Corolla | 191 psi (13.4 kg/cm 2 ) | ||
| MR2 | |||
| 2.0L | 164 psi (11.5 kg/cm 2 ) | ||
| 2.2L | 178 psi (12.5 kg/cm 2 ) | ||
| Pickup & 4Runner | 171 psi (12.0 kg/cm 2 ) | ||
| Tercel | 185 psi (13.0 kg/cm 2 ) | ||
| All Others | 178 psi (12.5 kg/cm 2 ) | ||
| Minimum Compression Pressure | |||
| Celica Turbo | 164 psi (11.5 kg/cm 2 ) | ||
| MR2 2.0L & Previa | 128 psi (9.0 kg/cm 2 ) | ||
| All Others | 142 psi (10.0 kg/cm 2 ) | ||
| Maximum Variation Between Cylinders | . 14 psi (1.0 kg/cm 2 ) | ||
COMPRESSION SPECIFICATIONS
Exhaust System Backpressure
The exhaust system can be checked with a vacuum or pressure gauge. Remove O2 sensor or air injection check valve (if equipped). Connect a 1-10 psi pressure gauge and run engine at 2500 RPM. If exhaust system backpressure is greater than 2 psi, exhaust system or catalytic converter is plugged.
If a vacuum gauge is used, connect vacuum gauge hose to intake manifold vacuum port and start engine. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge reading slowly drops after stabilizing, exhaust system should be checked for a restriction.
FUEL SYSTEM
Basic diagnosis of fuel system should begin with determining fuel system operation and pressure.
| WARNING | ALWAYS relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components. |
Fuel Pressure Release
Disconnect negative battery terminal. Place container under fitting to be loosened. Use a rag to cover fuel line/component. Slowly loosen fitting, allowing pressurized fuel to spill into container. After fuel system has depressurized, disconnect and plug fitting.
EFI Main Relay
- EFI fuse supplies constant battery voltage to EFI main relay. EFI main relay provides battery voltage to +B terminal of circuit opening relay and engine check connector.
- If fuel pump does not turn on when +B and FP pins are jumpered with ignition on, check EFI main relay. (Scheme 15) Also check EFI main relay circuit. Depending on model, relay may either be turned on directly by ignition switch or by M-REL terminal of ECU. For more information on wiring, see WIRING DIAGRAMS article in this section in this section.
Scheme 15
Circuit Opening Relay
- Circuit opening relay controls fuel pump circuit. ECU receives an input signal at STA terminal when engine is cranking. This starter signal is also applied to terminal STA of circuit opening relay.
- Starter signal energizes circuit opening relay during cranking, which in turn activates fuel pump. On all models except Celica, Corolla (4A-FE) and Tercel, fuel pump switch in airflow meter provides relay ground. On Celica, Corolla (4A-FE) and Tercel, circuit opening relay is grounded by ECU through FC terminal.
Fuel Pump Relay & Fuel Pump Resistor (Celica 2.0L Turbo)
These models use a separate fuel pump relay and resistor between circuit opening relay and fuel pump.
Note. For more information on testing relays and fuel system components, see I - SYS/COMP TESTS article in this section.
Code 12 (No RPM Signal)
ECU will store Code 12 in memory if it does not receive signal from either NE pick-up coil (RPM) or "G" pick-up coil (crank position) terminal within 2 seconds of engine cranking.
Code 13 (No RPM Signal)
ECU will store Code 13 in memory if it does not receive signal from NE pick-up coil (RPM) terminal when engine speed is above 1000 RPM.
Code 14 (Ignition Signal Problem)
ECU will store Code 14 in memory if it does not receive IGF (ignition detection) signal a specified number of times. Refer to the CODE 14 SET SPECIFICATIONS table.
| Application | No. Times W/O IGF Signal | |
|---|---|---|
| Camry, Celica (2.2L) | ||
| Pickup (2.4L) & 4Runner (2.4L) | 4-5 | |
| Celica (1.6L) & Tercel | 4 | |
| Celica (2.0L) & MR2 | 8-11 | |
| Previa | 8-9 | |
CODE 14 SET SPECIFICATIONS
Camry (2.0L) & Tercel
- Measure pick-up coil resistance between terminals "G" and G(-) and between terminals NE and G(-). (Scheme 16)
- If resistance is not within specification, replace distributor. See «DISTRIBUTOR PICK-UP COIL RESISTANCE»(ref-21012-S30476955402001010300000) table. If resistance is within specification, proceed to «PICK-UP COIL AIR GAP CHECK»(ref-21012-S09423188202001010300000).
Pick-up Coil Connector ID (Camry & Tercel) Toyota Motor Sales, U.S.A., Inc. Scheme 16
Celica (1.6L) & Corolla (4A-FE)
- Measure pick-up coil resistance between terminals G(+) and G(-) and between terminals NE(+) and G(-). (Scheme 17)
- If resistance is not within specification, replace distributor. See «DISTRIBUTOR PICK-UP COIL RESISTANCE»(ref-21012-S30476955402001010300000) table. If resistance is within specification, proceed to «PICK-UP COIL AIR GAP CHECK»(ref-21012-S09423188202001010300000).
Pick-up Coil Connector ID (Celica 1.6 & Corolla 4A-FE) Toyota Motor Sales, U.S.A., Inc. Scheme 17
Celica (2.0L), MR2 (2.0L) & Previa
- Measure resistance of pick-up coil between terminals G1 and G(-), G2 and G(-) and NE and G(-). (Scheme 18)
- If resistance is not within specification, replace distributor. See «DISTRIBUTOR PICK-UP COIL RESISTANCE»(ref-21012-S30476955402001010300000) table. If resistance is within specification, proceed to «PICK-UP COIL AIR GAP CHECK»(ref-21012-S09423188202001010300000).
Pick-up Coil Connector ID (Celica 2.0L, MR2 2.0L & Previa) Toyota Motor Sales, U.S.A., Inc. Scheme 18
Celica (2.2L) & MR2 (2.2L)
- Measure pick-up coil resistance between terminals G1 and G(-) and between NE and G(-). (Scheme 19)
- If resistance is not within specification, replace distributor. See «DISTRIBUTOR PICK-UP COIL RESISTANCE»(ref-21012-S30476955402001010300000) table. If resistance is within specification, proceed to «PICK-UP COIL AIR GAP CHECK»(ref-21012-S09423188202001010300000).
Pick-up Coil Connector ID (Celica 2.2L & MR2 2.2L) Toyota Motor Sales, U.S.A., Inc. Scheme 19
Corolla (4A-GE)
- Measure pick-up coil resistance between terminals G(+) and G(-) and between NE(+) and NE(-). (Scheme 20)
- If resistance is not within specification, replace distributor. See «DISTRIBUTOR PICK-UP COIL RESISTANCE»(ref-21012-S30476955402001010300000) table. If resistance is within specification, proceed to «PICK-UP COIL AIR GAP CHECK»(ref-21012-S09423188202001010300000).
Pick-up Coil Connector ID (Corolla 4A-GE) Toyota Motor Sales, U.S.A., Inc. Scheme 20
Pickup (2.4L) & 4Runner (2.4L)
- Measure resistance of pick-up coil between terminals NE (+) and NE (-). (Scheme 21)
- If resistance is not within specification, replace distributor. See «DISTRIBUTOR PICK-UP COIL RESISTANCE»(ref-21012-S30476955402001010300000) table. If resistance is within specification, proceed to «PICK-UP COIL AIR GAP CHECK»(ref-21012-S09423188202001010300000).
Pick-up Coil Connector ID (Pickup & 4Runner) Toyota Motor Sales, U.S.A., Inc. Scheme 21
| Application | Ohms | |
|---|---|---|
| Celica (1.6L) & Corolla (4A-FE) | 140-180 | |
| Celica (2.0L), MR2 (2.0L) & Previa | ||
| Pick-Up Coil G1 | 125-190 | |
| Pick-Up Coil G2 | 125-190 | |
| Pick-Up Coil NE | 155-240 | |
| Celica (2.2L) & MR2 (2.2L) | 150-230 | |
| Tercel | ||
| Gray | 265-420 | |
| Green | 370-530 | |
| All Others | ||
| Gray | 130-210 | |
| Green | 185-265 | |
DISTRIBUTOR PICK-UP COIL RESISTANCE
PICK-UP COIL AIR GAP CHECK
- Using a flat, non-magnetic feeler gauge, check air gap between signal rotor and pick-up coil projection. (Scheme 22)-37.
- Air gap should be within specification. See «PICK-UP COIL ADJUSTMENT»(ref-21012-S17293931622001010300000) table. If air gap is not within specification, replace distributor.
| Application | In. (mm) |
|---|---|
| Camry, Celica (Non-Turbo) & Corolla (4A-FE) | (1) At least .008 (.20) |
| Celica (Turbo), Corolla (4A-GE), MR2, Pickup, Previa, Tercel & 4Runner | (1) .008-.016 (.20-.40) |
| (1) Replace distributor if not within specification. | |
| (1) | Replace distributor if not within specification. |
PICK-UP COIL ADJUSTMENT
Scheme 22
Scheme 23
Scheme 24
Scheme 25
Scheme 26
Scheme 27
IDLE SPEED & IGNITION TIMING
Ensure idle speed and ignition timing are set to specification. For adjustment procedures, see ADJUSTMENTS article in this section.
IDLE SPEED
| Application | RPM | |||
|---|---|---|---|---|
| Camry | (1) 650 | |||
| Celica | ||||
| 1.6L | 800 | |||
| 2.0L | 750-850 | |||
| 2.2L | (1) 650 | |||
| Corolla | ||||
| 4A-FE | ||||
| 2WD | ||||
| Federal | 700 | |||
| California | 800 | |||
| 4WD | 800 | |||
| 4A-GE | 800 | |||
| MR2 | ||||
| 2.0L | 750-850 | |||
| 2.2L | 650 | |||
| Pickup | ||||
| 4WD & A/T | 850 | |||
| All Others | 750 | |||
| 4Runner | 750 | |||
| Previa | 750 | |||
| Tercel | 800 | |||
| (1) Idle speed with jumper wire removed is 650-750 RPM. | ||||
| (1) | Idle speed with jumper wire removed is 650-750 RPM. |
IDLE SPEED SPECIFICATIONS
IGNITION TIMING
| Application | (2) Base Timing | Advance Timing | |
|---|---|---|---|
| Camry & Celica | |||
| 1.6L | 10 @ Idle | 5-15 @ Idle | |
| 2.0L | 10 @ 750 | 14-19 @ Idle | |
| 2.2L | 10 @ 700 | 13-22 @ Idle | |
| Corolla | |||
| 4A-FE | 10 @ 800 | 5-15 @ Idle | |
| 4A-GE | 10 @ 800 | 16 @ Idle | |
| MR2 | |||
| 2.0L | 10 @ Idle | 12-21 @ Idle | |
| 2.2L | 10 @ Idle | 13-22 @ Idle | |
| Pickup & 4Runner | 5 @ Idle | 10-14 @ Idle | |
| Previa | 5 @ Idle | 12 @ Idle | |
| Tercel | 10 @ Idle | 7-17 @ Idle | |
| (1) Degrees BTDC @ RPM (2) With check connector terminals TE1 and E1 jumpered. | |||
| (1) | Degrees BTDC @ RPM |
| (2) | With check connector terminals TE1 and E1 jumpered. |
IGNITION TIMING (1)
SUMMARY
If no faults were found while performing BASIC TESTING , proceed to TESTS W/CODES article in this section. If no hard codes are found in self-diagnostics, proceed to TESTS W/O CODES article in this section for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.