Scheme 37
Scheme 37: EGR VACUUM MODULATOR
- EGR vacuum modulator may be a 2 port or 3 port depending on application. On 2 port models, disconnect hoses from vacuum modulator. Plug one end of hose connection on EGR vacuum modulator.
- Apply air pressure through remaining port. Air should pass freely through air filter side. On 3 port models, disconnect all hoses. Block "P" and "R" ports. Apply air pressure to "Q" port. (Scheme 37) Air should pass through the air filter side freely.
- On all models, operate engine at specified RPM. See «EGR VACUUM MODULATOR SPECIFICATIONS»(/toyota/camry/v20-1986-1991/remont/testing-diagnostics/#egr-function-testing) table. Repeat previous test procedure. Strong resistance of airflow should be felt. Replace EGR vacuum modulator if resistance is not felt.
Camry (2.5L), Corolla (EFI), Corolla FX-16, MR2, Pickup (Turbo), Tercel Sedan & Van
- Drain cooling system and remove BVSV. Using cool water, cool BVSV to below minimum temperature according to application. See «BVSV SPECIFICATIONS»(/toyota/camry/v20-1986-1991/remont/testing-diagnostics/#egr-function-testing) table.
- On all models except Tercel Sedan, apply air through top port of valve. Air should not exhaust through bottom port. Heat BVSV valve to above maximum temperature according to application. See «BVSV SPECIFICATIONS»(/toyota/camry/v20-1986-1991/remont/testing-diagnostics/#egr-function-testing) table. Apply air in top port. Air should exhaust through lower port. Replace assembly if defective.
- On Tercel Sedan with M/T, a 3 port BVSV is used while a 2 port is used on A/T applications. On both applications, cool BVSV to below minimum temperature. See «BVSV SPECIFICATIONS»(/toyota/camry/v20-1986-1991/remont/testing-diagnostics/#egr-function-testing) table.
- On A/T models, apply air to top port of valve. Air should exhaust from lower port. On M/T models, apply air to the center port. Air should exhaust from the upper and lower ports.
- Heat BVSV valve to above maximum temperature. See «BVSV SPECIFICATIONS»(/toyota/camry/v20-1986-1991/remont/testing-diagnostics/#egr-function-testing) table. On A/T models, apply air to top port. Air should not exhaust through lower port. On M/T models, apply air to the center port. Air should not exhaust through any port. Replace assembly if defective.
Camry (2.0L), Pickup (2.4L Carbureted & Non-Turbo), 4Runner (2.4 EFI) & Celica (2WD)
- Drain cooling system and remove BVSV. Cool BVSV to minimum temperature according to application using cool water. See «BVSV SPECIFICATIONS»(/toyota/camry/v20-1986-1991/remont/testing-diagnostics/#egr-function-testing) table.
- Apply air to the lower port. Air should escape from air filter located on top of valve assembly. Heat BVSV valve to maximum temperature according to application. See «BVSV SPECIFICATIONS»(/toyota/camry/v20-1986-1991/remont/testing-diagnostics/#egr-function-testing) table.
- Apply air to the lower port. Air should exhaust from the upper port but not through the air filter. Replace assembly if defective.
- Ensure modulator filter is clean and in good condition prior to performing test. Clean filter with compressed air if necessary. Disconnect vacuum hose from EGR valve.
- Using a "T" connector, connect a vacuum gauge in EGR valve line. Check that engine starts and runs at idle. This ensures proper seating of EGR valve.
- The BVSV, TVSV, VSV and EGR modulator can be checked with engine coolant below minimum temperature and specified engine RPM in accordance with application. See «EGR SPECIFICATIONS»(/toyota/camry/v20-1986-1991/remont/testing-diagnostics/#egr-function-testing) table. Different valves are used depending on model. (Scheme 38)through (Scheme 53).
- Operate engine with engine coolant below minimum temperature and specified RPM. No vacuum reading should be obtained when operated with engine coolant below minimum temperature.
- Operate engine at normal operating temperature and specified RPM. See «EGR SPECIFICATIONS»(/toyota/camry/v20-1986-1991/remont/testing-diagnostics/#egr-function-testing) table for specified engine RPM. Low vacuum reading should be obtained.
- Vacuum reading of 2.6 in. Hg should be obtained on Cressida and Supra models. On Cressida, Land Cruiser, Pickup and 4Runner (3.0L) and Supra non-turbo models, check that no vacuum is shown at idle. Also check Corolla models with EFI, Corolla FX-16 and the MR2 models at 5000 RPM. No vacuum should exist.
- Disconnect hose from the "R" port of EGR vacuum modulator on all models except the Celica 4WD, Tercel Wagon, Pickup (turbo) and Supra (turbo) models. (Scheme 38)through (Scheme 53).
- Using additional hose, connect "R" port directly to intake manifold. High vacuum reading should be obtained at specified engine RPM. See «EGR SPECIFICATIONS»(/toyota/camry/v20-1986-1991/remont/testing-diagnostics/#egr-function-testing) table. NOTE: Engine should misfire due to large amounts of exhaust gas being injected into intake manifold.
- Disconnect vacuum gauge and install vacuum hoses. To check EGR valve, apply vacuum directly to EGR valve with engine idling. Engine should run rough. If system did not operate within specifications, each component should be tested. See «COMPONENT TEST»(/toyota/camry/v20-1986-1991/remont/testing-diagnostics/#egr-function-testing)
Scheme 38
Scheme 39
Scheme 40
Scheme 41
Scheme 42
Scheme 43
Scheme 44
Scheme 45
Scheme 46
Scheme 47
Scheme 48
Scheme 49
Scheme 50
Scheme 51
Scheme 52
Scheme 53
| Model | Minimum Temperature | Engine RPM |
| Camry |
| 2.0L | 113°F (45°C) | (1) 2500 |
| 2.5L | 104°F (40°C) | 2500 |
| Celica |
| 2WD | 113°F (45°C) | 2500 |
| 4WD | 129°F (45°C) | 2500 |
| Corolla |
| Carbureted | 122°F (50°C) | 2000 |
| EFI | 95°F (35°C) | 3500 |
| Corolla FX | 122°F (50°C) | 2000 |
| Corolla FX-16 | 95°F (35°C) | 3500 |
| Cressida | 135°F (57°C) | 2500 |
| Land Cruiser | 127°F (53°C) | 2500 |
| MR2 | 95°F (35°C) | 3500 |
| Pickup |
| 2.4L |
| Carbureted | 113°F (45°C) | 3000 |
| EFI | 86°F (30°C) | (2) 3500 |
| 3.0L | 118°F (48°C) | 3500 |
| Supra | 135°F (57°C) | 2500 |
| Tercel |
| Sedan | 104°F (40°C) | 3000 |
| Wagon | 122°F (50°C) | 3000 |
| Van | 104°F (40°C) | 3500 |
| 4Runner |
| 2.4L | 86°F (30°C) | (2) 3500 |
| 3.0L | 118°F (48°C) | 3500 |
| (1) Check at 3500 RPM with hose from EGR to manifold. (2) Check at 3000 RPM with hose from EGR to manifold. |
| (1) | Check at 3500 RPM with hose from EGR to manifold. |
| (2) | Check at 3000 RPM with hose from EGR to manifold. |
EGR VACUUM MODULATOR
| Application | Engine RPM |
| 2-Port Type |
| Celica 4WD | 2500 |
| Pickup (Turbo) | 3500 |
| Supra (Turbo) | 2500 |
| Tercel Wagon | 3000 |
| 3-Port Type |
| Camry |
| 2.0L | 2500 |
| 2.5L | 3500 |
| Celica 2WD | 2500 |
| Corolla |
| Carbureted | 2000 |
| EFI | 3500 |
| Corolla FX | 2000 |
| Corolla FX-16 | 3500 |
| Cressida | 2500 |
| Land Cruiser | 2500 |
| MR2 | 3500 |
| Pickup |
| 2.4L Carbureted | 3000 |
| 2.4L Non-Turbo | 3500 |
| 3.0L | 2500 |
| 4Runner |
| 2.4L | 3500 |
| 3.0L | 2500 |
| Supra (Non-Turbo) | 2500 |
| Tercel Sedan | 3000 |
| Van | 3500 |
EGR VACUUM MODULATOR SPECIFICATIONS
BVSV
| Application | Minimum Temperature | Maximum Temperature |
| Camry |
| 2.0L | 113°F (45°C) | 151°F (66°C) |
| 2.5L | 104°F (40°C) | 129°F (54°C) |
| Celica 2WD | 113°F (45°C) | 151°F (66°C) |
| Corolla (EFI) | 95°F (35°C) | 129°F (54°C) |
| Corolla FX-16 | 95°F (35°C) | 129°F (54°C) |
| Pickup |
| 2.4L Carbureted | 113°F (45°C) | (1) * |
| 2.4L EFI & Turbo | 86°F (30°C) | 111°F (44°C) |
| MR2 | 95°F (35°C) | 129°F (54°C) |
| Tercel Sedan | 104°F (40°C) | 129°F (54°C) |
| Van 2.4L | 104°F (40°C) | 129°F (54°C) |
| 4Runner 2.4L EFI | 86°F (30°C) | 111°F (44°C) |
| (1) California models is 147°F (64°C) and 151°F (66°C) on Federal models. |
| (1) | California models is 147°F (64°C) and 151°F (66°C) on Federal models. |