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Eric, Automotive Repair Shop Manager
Category: Toyota
Satisfied Customers: 32399
Experience:  20+ yrs. experience as repair shop manager and technician.
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95 Toyota 4runner: EGR Valve..a vacuum smoke test and smoke..metal

Resolved Question:

95 Toyota 4runner EGR Valve question. Did a vacuum smoke test and smoke was coming out of the EGR round metal part. I would think that means it's bad part. The engine hesitates when pressing gas pedal when starting 1 gear through out all gears when rpms up 2500+ it seems to run ok. Is it likely the EGR is bad? and could it be causing the engine problem? Where could I get the part cheaper than $170? I did a exhaust test which tested good. The timing I set forward. It does not run/idle well set to factory. New spark plugs, wires, cap and roter. New timing belt, radiator, waterpump, thermistat (should not matter). Help.
Submitted: 5 years ago.
Category: Toyota
Expert:  Eric replied 5 years ago.



ok you to check for codes and due a vacuun test to check the diagram. Here is below how to do so far testing a possible causes.


Tests/Procedures: 1. Monitor the voltage on the EGR temperature sensor Green/White (GRN/WHT) wire. The voltage needs to drop below 1 volt when the EGR valve is operating. The voltage needs to drop fast, so the Engine Control Module (ECM) knows that the EGR flow is correct.

2. If the EGR temperature sensor voltage does not drop below 1 volt, or is slow to drop, verify that there is correct vacuum (4 to 7 inches) to the EGR valve while driving.

3. If the vacuum is correct, then check the EGR passages for carbon and verify that the EGR temperature sensors ground is good. If the voltage still will not drop, then check for a faulty EGR temperature sensor.

4. If all tests show that everything is working at this time, the EGR Vacuum Switching Valve (VSV) is common to fail intermittently and may need to be replaced.

Potential Causes: Exhaust Gas Recirculation (EGR) Modulator
Restricted Exhaust Gas Recirculation (EGR) Passages
Exhaust Gas Recirculation (EGR) Temperature Sensor
Exhaust Gas Recirculation (EGR) Vacuum Solenoid Valve (VSV)
Restricted Vacuum Ports

Customer: replied 5 years ago.
So you are saying that while engine not running using a vacuum smoke tester, smoke coming out of the EGR valve does not mean its bad? We did find a hose off by doing this test.
Expert:  Eric replied 5 years ago.

no, you test while runniing the engine for a smoke test.

did you redo the test after reconnecting the bad hose?

is the smoke coming from the base of the egr valve or from the middle of the egr valve itself?
Customer: replied 5 years ago.
Out of the silver round top part. There holes underneath smoke coming out of.
Expert:  Eric replied 5 years ago.

ok, that would definitely be a bad EGR valve. And yes, a bad EGR valve can and will cause driveabilty issues such as hesitation, power loss among them.

replace your EGR valve. the cheapest I found one is $152 at
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