EGR valve delete

Hi and thanks for using 2CarPros.com.

You should replace the EGR if it is bad. The bottom line, there is a check engine light and it will set if the EGR is removed. The light may not come on right away. However, once the computer goes through test sequences, it will eventually come on. Additionally, removing the EGR will increase the emissions produced by the engine, specifically, nox gases. Removing the EGR will end up setting other codes, too. Also, there could be a code already stored in the system. Here are directions on how to check an OBD1 system:

https://www.2carpros.com/articles/retrieve-trouble-codes-for-chrysler-dodge-plymouth-odb1-1995-and-earlier-car-mini-van-and-light-trucks

Check to see if there are codes. Honestly, the EGR does hardly anything at low idle speeds. Very little exhaust gases are recirculated at low engine speeds. If there were higher amounts, the engine would not run. Have you checked for a vacuum leak? Have you checked fuel pump pressure?

Let me know.
Joe

Happy to help.

I have to be honest. What you are describing sounds like a bad idle air control valve (IAC). It is located on the front of the throttle body and its only job is to maintain engine idle speed. What I suggest is to remove it and check to see if there is any issues with carbon. Also, have a helper turn the key on and off to see if the small pintle on the end moves.

Here are the directions for removal and replacement. It is really simple. The picture attached shows its location.

AC Motor Removal
REMOVAL

1. Remove air cleaner assembly.
2. Disconnect the negative battery terminal.
3. Disconnect the Idle Air Control (IAC) motor wiring connector.
4. Remove the Torx head mounting screws (2), and remove the IAC from throttle body.

INSTALLATION

1. Install new IAC motor.

NOTE: If the pintle measures more than 1 in (25 mm), it must be retracted by using the IAC exerciser (Tool # 7558). The battery must be connected for this procedure.

2. Install the Torx head retaining screws, torquing them to 20 in-lbs (2 Nm).
3. Connect the IAC motor electrical connector.
4. Connect the negative battery cable.
5. Install the air cleaner assembly.
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Here are specific directions for testing:

IDLE AIR CONTROL (IAC) MOTOR
CAUTION: Proper safety precautions must be taken when testing the Idle Air Control (IAC) motor.

NOTE: To perform a complete test of IAC motor and its circuitry, refer to appropriate Powertrain Diagnostics Chart. To test the IAC motor only, special IAC motor exerciser tool number 7558 may be used.

Set the parking brake and block the drive wheels
Route all tester cables away from the cooling fans, drive belt, pulleys and exhaust components
Provide proper ventilation while operating the engine
Always return the engine idle speed to normal before disconnecting the exerciser tool.

PROCEDURE
1. With the ignition OFF, disconnect the IAC motor wire connector at throttle body.

2. Plug the exerciser tool (7558) harness connector into the IAC motor.

3. Connect the red clip of exerciser tool (7558) to battery positive terminal. Connect the black clip to negative battery terminal. The red light on the exerciser tool will be illuminated when the exerciser is properly connected to battery.

4. Start engine.

When the switch is in the HIGH or LOW position, the light on the exerciser tool will flash. This indicates that voltage pulses are being sent to the IAC stepper motor.

5. Move the switch to the HIGH position. The engine speed should increase. Move the switch to the LOW position. The engine speed should decrease.

a. If the engine speed changes while using the exerciser tool, the IAC motor is functioning properly. Disconnect the exerciser tool and connect the IAC stepper motor wire connector to the stepper motor.

b. If the engine speed does not change, turn the ignition OFF and proceed to step 6. Do not disconnect exerciser from the IAC stepper motor.

6. Remove the IAC stepper motor from the throttle body.

CAUTION: When checking IAC motor operation with the motor removed from the throttle body, do not extend the pintle more than 6.35 mm (0.250 in). If the pintle is extended more than this amount, it may separate from the IAC stepper motor. The IAC motor must be replaced if the pintle separates from the motor.

7. With the ignition OFF, cycle the exerciser tool switch between the HIGH and LOW positions. Observe the pintle. The pintle should move in-and-out of the motor.

a. If the pintle does not move, replace the IAC motor. Start the engine and test the replacement motor operation as described in step (5).

b. If the pintle operates properly, check the IAC motor bore in the throttle body bore for blockage and clean as necessary. Install the IAC motor and retest. If blockage is not found, refer to the DRB II scan tool and the appropriate Powertrain Diagnostics Procedures service manual.

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Take a look at this link. The first thing it talks about is the IAC and what problems may occur. In general, it discusses idle issues.

https://www.2carpros.com/articles/engine-idles-too-high

Let me know if this helps.

Take care,
Joe

Yes, there can be a build up. Also, make sure it is working. You may have a bad or damaged connections. Read through the link that I sent. It discusses possible issues with the IAC system.

The problem with vehicles which have so many sensors and computers to operate them is one can never tell what the problem is coming from. To answer your question, yes. It could run rich all the time if the computer thinks more air in going into the engine than actually is.

I was thinking about this issue. This vehicle has a coolant temperature sensor that sends a signal to the computer. It tells the computer the coolant's temperature, and from that the computer decides how rich or lean to make the fuel mixture. For example, if the sensor is telling the computer it is 5 degrees F, the fuel mixture will be rich. Check that component. I have attached the component location and directions for testing it.

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COOLANT TEMPERATURE SENSOR
Coolant Temperature Sensor Test
NOTE:
To perform a complete test of the Coolant Temperature Sensor and its circuitry, refer to the DRB II diagnostic tester. Also refer to the appropriate DIAGNOSTIC CHARTS. To test the sensor only, refer to the following:

PROCEDURE

1. Turn the ignition key to the OFF position.

2. Disconnect wire connector from coolant temperature sensor.

NOTE: Engines with air conditioning: When removing the connector from sensor, do not pull directly on wiring harness. Fabricate an L shaped hook tool from a coat hanger (approximately eight inches long). Place the hook part of tool under the connector for removal. The connector is snapped onto the sensor. It is not equipped with a lock type tab.

3. Connect one lead of ohmmeter to one terminal of coolant temperature sensor.

4. Connect the other lead of ohmmeter to remaining terminal of coolant temperature sensor.

For resistance (in ohms) at given temperatures, See SPECIFICATIONS.

Replace sensor if resistance readings are incorrect.

.

TEMPERATURE RESISTANCE (OHMS)

°C °F MIN MAX
.

-40 -4O 291,490 381,710

-20 -4 85,850 108,390

-10 14 49,250 61,430

0 32 29,330 35,990

10 50 17,990 21,810

20 68 11,370 13,610

25 77 9,120 10,880

30 86 7,370 8,750

40 104 4,900 5,750

50 122 3,330 3,880

60 14O 2,310 2,670

70 158 1,630 1,870

80 176 1,170 1,340

90 194 860 970

100 212 640 720

110 230 480 540

120 248 370 410

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Check how much resistance is in the switch in relationship to the ambient temperature. Let me know the results.

Joe

What was the temperature when tested?

If your readings are correct, the sensor is bad.

Joe is one of our best! Please let us know what happens.

Cheers, Ken

Happy to help. Let us know if you have questions in the future.

Take care,
Joe