EGR VALVE..

[Tyler]

I searched the boards and the technical database for answers.. but no luck..


what is the EGR valve and where is it located?

thx

[ September 18, 2002: Message edited by: Tyler ]</p>

[Tyler]

thanks for the replies.. i really appreciate it [img]graemlins/thumbsdown.gif[/img] :rolleyes:

[AZ3.8Camaro]

It recirculates some exhaust gas into you intake, Its for emissons, i don't know much about it, but I just thought I would tell you what I know so you didn't feel ignored, someone who knows will answer sooner or later.

[Blizzard96]

Recirculates some exhaust gas to be reburned (I think) and lower temps. Its an emission thing...I know here in California, you won't pass if its bad.

Its the little cylinder thing on the driver side with a wire going into it.

[HankHill]

<blockquote>quote:</font><hr>Originally posted by Tyler:
I searched the boards and the technical database for answers.. but no luck..
what is the EGR valve
[ September 18, 2002: Message edited by: Tyler ]<hr></blockquote>

Here's an explanation I found on the Olds site. More then anyone wants to know about the EGR valve [img]smile.gif[/img]
Purpose
The EGR system is used to lower NOx (oxides of of nitrogen) emissions levels caused by high combustion temperatures. It does this by decreasing combustion temperature.
The main element of the system is an EGR valve operated by vacuum, and mounted on the intake manifold.
The EGR valve feeds small amounts of exhaust gas back into the combustion chamber.
Operation
The EGR valve is opened by ported manifold vacuum to let exhaust gas flow into the intake manifold. The exhaust gas then moves with the air/fuel mixture into the combustion chamber. If too much exhaust gas enters, combustion will not occur. For this reason, very little exhaust gas is allowed to pass throw the valve, especially at idle. The EGR valve is usually open under the following conditions:
 Warm engine operation.
 Above idle speed.
The amount of exhaust gas recirculated is controlled by variations in vacuum and in some cases, exhaust back pressure
 Port EGR valve (3.8L)
This valve is controlled by a flexible diaphram which is spring loaded to hold the valve closed. Ported vacuum applied to the top side of the diaphragm overcomes spring pressure and opens the valve in the exhaust gas port. This allows exhaust gas to be pulled into the intake manifold and enter the engine cylinders.

EGR Control
To regulate EGR flow, an ECM controlled solenoid is used in the vacuum line. The ECM uses information from various combinations of the following sensors to regulate the solenoid:
 Coolant Temperature
 Throttle Position (TPS)
 Manifold Absolute Pressure (MAP) or vacuum.
 Park/Neutral switch.
 Distributor (RPM signal).

Pulse Width Modulated EGR Control (3.8L)
During cold engine operation, a "pulse width modulated" signal from the ECM energizes the EGR solenoid blocking vacuum to the EGR valve. "Pulse Width Modulation" means the ECM turns the solenoid on and off many times a second and varies the amount of "on" time ("pulse width") to vary the amount of EGR. The solenoid is also energized during cranking and at wide open throttle. When the engine warms up, the EGR solenoid is turned off and the EGR works on normal port vacuum and exhaust backpressure signals.
A diagnostic switch is part of the control and monitors vacuum to the EGR valve. This switch will trigger a "Service Engine Soon" light, and set a code in the event of a vacuum circuit failure.

Results of Incorrect EGR System Operation

Too much EGR tends to weaken combustion, causing the engine to run roughly or stop. With too much EGR at idle, cruise, or cold operation, any of the following conditions may happen:
 Engine stops after cold start.
 Engine stops at idle after deceleration.
 Car surges during cruise.
 Rough idle.
If the EGR valve should stay open all of the time, the engine may not idle.

Too little or no EGR flow allows combustion temperatures to get too high during acceleration and load conditions. This could case:
 Spark Knock (detonation).
 Engine overheating
 Emissions test failure.
You read this far....now your an expert on EGR

HH

[sped214]

it's mounted on your drivers side exhaust manifold. it's a black tube looking thing with a wire connector coming out the top.