EGR Function Testing Toyota MR2 W10

Scheme 32

1. 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.
2. 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 32) Air should pass through the air filter side freely.
3. On all models, operate engine at specified RPM due to model application. See «EGR VACUUM MODULATOR SPECIFICATIONS»(/toyota/mr2/w10-1984-1990/remont/testing-diagnostics/#egr-function-testing) table. Repeat previous test procedure. Strong resistance of air flow should be felt. Replace EGR vacuum modulator if resistance is not felt.

Corolla (EFI), Land Cruiser, MR2, Pickup (Turbo), 4Runner, Tercel Sedan & Van

1. Drain cooling system and remove BVSV. Cool BVSV to minimum temperature according to application using cool water. See «BVSV SPECIFICATIONS»(/toyota/mr2/w10-1984-1990/remont/testing-diagnostics/#egr-function-testing) table.
2. On all models except Tercel Sedan, apply air through top port of valve. Air should not exhaust through bottom port. Heat BVSV valve to maximum temperature according to application. See «BVSV SPECIFICATIONS»(/toyota/mr2/w10-1984-1990/remont/testing-diagnostics/#egr-function-testing) table. Apply air in top port. Air should exhaust through lower port. Replace assembly if defective.
3. On Tercel Sedan with M/T, a 3 port BVSV is used while a 2 port is used on A/T applications. Cool BVSV to minimum temperature according to application using cool water. See «BVSV SPECIFICATIONS»(/toyota/mr2/w10-1984-1990/remont/testing-diagnostics/#egr-function-testing) table.
4. 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.
5. Heat BVSV valve to maximum temperature according to application. See «BVSV SPECIFICATIONS»(/toyota/mr2/w10-1984-1990/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.

Pickup (Carbureted & Non-Turbo), 4Runner (Non-Turbo) & Celica

1. Drain cooling system and remove BVSV. Cool BVSV to minimum temperature according to application using cool water. See «BVSV SPECIFICATIONS»(/toyota/mr2/w10-1984-1990/remont/testing-diagnostics/#egr-function-testing) table.
2. 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/mr2/w10-1984-1990/remont/testing-diagnostics/#egr-function-testing) table.
3. Apply air to the lower port. Air should exhaust from the upper port but not through the air filter. Replace assembly if defective.

Corolla (Carbureted) & Tercel Wagon

1. Drain cooling system and remove TVSV. Cool TVSV to 45°F (7°C). Apply air pressure to port "J". (Scheme 33) Air should escape from ports "M" and "L".
2. Apply air pressure to port "K". Air should escape from port "N." Heat TVSV to 63-122°F (17-50°C). Apply air pressure to port "K". Air should escape from ports "N" and "L". Apply air pressure to port "J". Air should escape from port "M".
3. Heat TVSV to 154°F (68°C). Apply air pressure to port "K". Air should escape from ports "M" and "L". Apply air pressure to port "J". Air should not escape from any ports. Replace assembly if defective.

Scheme 33

Corolla (EFI) & MR2

1. Connect battery terminals to VSV terminals. Apply air pressure to the inside port closest to valve assembly. Air should escape from outer port. Disconnect battery terminals. Air should now escape from air filter at end of valve assembly.
2. Using ohmmeter, check for continuity between terminals and VSV body. If continuity exists, unit is shorted. Replace valve if defective.
3. Using ohmmeter, measure resistance between both terminals of valve assembly. Resistance should be 33-39 ohms at 68°F (20°C). Replace valve if resistance is not within specification.

Cressida & Supra (Non-Turbo)

1. Connect battery terminals to VSV terminals. Apply air pressure to the inside port closest to valve assembly. Air should escape from outer port. Disconnect battery terminals. Air should not escape from outer port.
2. Using ohmmeter, check for continuity between terminals and VSV body. If continuity exists, unit is shorted. Replace valve if defective.
3. Using ohmmeter, measure resistance between both terminals of valve assembly. Resistance should be 38-44 ohms at 68°F (20°C). Replace valve if resistance is not within specification.

Supra (Turbo)

1. Connect battery terminals to VSV terminals. Apply air pressure to the port located next to air filter. Air should escape from port located in opposite end of valve assembly.
2. Disconnect battery terminals. Air should now escape through air filter. Using ohmmeter, check for continuity between terminals and VSV body. If continuity exists, unit is shorted. Replace valve if defective.
3. Using ohmmeter, measure resistance between both terminals of valve assembly. Resistance should be 38-44 ohms at 68°F (20°C). Replace valve if resistance is not within specification.

Land Cruiser

1. Connect battery terminals to VSV terminals. Apply air pressure to the inside port closest to valve assembly on the double port end of valve. Air should escape from outer port on double port end of valve.
2. Disconnect battery terminals. Air should now escape from end port on opposite end of valve. Using ohmmeter, check for continuity between terminals and VSV body. If continuity exists, unit is shorted. Replace valve if defective.
3. Using ohmmeter, measure resistance between both terminals of valve assembly. Resistance should be 38-43 ohms at 68°F (20°C). Replace valve if resistance is not within specification.

Pickup & 4Runner (Turbo)

1. Using vacuum pump, apply 1.18 in. Hg to port "S". (Scheme 34) With vacuum applied air should be drawn in at port "Z". Remove vacuum supply.
2. Apply air pressure at port "Z". Air should escape through air filter. Replace valve assembly if defective.

Scheme 34

VACUUM CHECK VALVE

Apply air pressure to one side of check valve. Air pressure should flow easily in one direction and should not flow through valve when air pressure is reversed.

Cressida & Supra

Temperature sensor resistance should be tested. See COMPUTERIZED ENGINE CONTROL article in the COMPUTER CONTROLS section.

EGR SYSTEM

1. 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.
2. 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.
3. The BVSV, TVSV, VSV and EGR modulator can be checked with engine coolant at certain temperatures and engine RPM in accordance with application. See «EGR SYSTEM SPECIFICATIONS»(/toyota/mr2/w10-1984-1990/remont/testing-diagnostics/#egr-function-testing) table. Different valves are used depending on model.
4. Operate engine at minimum temperature and RPM. No vacuum reading should be obtained when operated at minimum temperature. Operate engine at normal operating temperature and specified RPM.
5. Low vacuum reading should be obtained. Vacuum reading of 2.6 in. Hg should be obtained on Cressida and Supra models. On Cressida and non-turbo Supra models, check that no vacuum is shown at idle. Corolla models with EFI and the MR2 models should be checked at 5000 RPM showing no vacuum.
6. Disconnect hose from the "R" port of EGR vacuum modulator on all models except the Tercel Wagon, Pickup, 4Runner with EFI and turbocharged Supra. (Scheme 35)through (Scheme 47)..
7. Using additional hose, connect "R" port directly to intake manifold. High vacuum reading should be obtained at specified RPM. See «EGR SYSTEM SPECIFICATIONS»(/toyota/mr2/w10-1984-1990/remont/testing-diagnostics/#egr-function-testing) table. Disconnect vacuum gauge and install vacuum hoses. NOTE: Engine should misfire due to large amounts of exhaust gas being injected into intake manifold.
8. 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/mr2/w10-1984-1990/remont/testing-diagnostics/#egr-function-testing).

Scheme 35

Scheme 36

Scheme 37

Scheme 38

Scheme 39

Scheme 40

Scheme 41

Scheme 42

Scheme 43

Scheme 44

Scheme 45

Scheme 46

Scheme 47

EGR SYSTEM SPECIFICATIONS

EGR VACUUM MODULATOR

EGR VACUUM MODULATOR SPECIFICATIONS

BVSV

BVSV SPECIFICATIONS

See also:
• EGR VACUUM MODULATOR SPECIFICATIONS