What's the correct procedure to check the operation of the EGR system? I don't have any codes yet but I'm just curious whether it even works properly on my 12 year old car or not.

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'88 IROC 305 TPI
Gutted airboxes
160 degree T-stat
Advanced base TPS voltage
Relocated IAT sensor
Momo steering wheel
Ram-air setup coming soon
Flowmaster muffler
Taylor SpiroPro wires
Accel cap and rotor

 

88,

For an engine operating with the O.E.M. PROM in the ECM, the EGR will only operate under several conditions:

* EGR Duty-cycle enabled at 56°C (133°F) CTS;
* EGR Duty-cycle at MAX >80°C (176°F) CTS;
* TPS must be between 1.2 and 4.0 VDC;
* O2 sensor must be varying off the bias voltage;
* MAT must be above 30°C (86°F);
* Engine RPM must be over 1,000.

If all the above conditions exist, the EGR solenoid should be energized. If the ECM does not measure a voltage rise at the EGR control terminal (A4) load sensing resistor, the ECM will set a DTC #32 (#31 for '88-'91 TBI engines).

Once the solenoid is energized, the ECM will wait six seconds to get an increase in the EGR temperature diagnostic sensor input. If the sensor input does not increase, the ECM will set a DTC #32.

This would mean that the system is at least functional. The only other check is to assure that the EGR valve is fully closing. High idle, poor idle quality, low vacuum, and poor throttle response should be present if the valve is not closing properly.

If you can reach the underside of the valve, you can manually operate the valve diaphragm to determine if the pintle is opening and the ports are not clogged.

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Later,
Vader
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"Make Me Bad"
Adobe Acrobat Reader 4.0

 

So basically if the computer isn't throwing any codes and the car's running fine, there is no need to fool around with it right?

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'88 IROC 305 TPI
Gutted airboxes
160 degree T-stat
Advanced base TPS voltage
Relocated IAT sensor
Momo steering wheel
Ram-air setup coming soon
Flowmaster muffler
Taylor SpiroPro wires
Accel cap and rotor

 

Correct.

You know what they say...If it aint broken, don't fix it.

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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R

GO #3

 

While we're on EGRs (again), I get an occassional code 32. So I throw my AutoX on it and watch things for a while, and I notice that the EGR Duty cycle is always either 0, or 100 (I think its actually 99 something). It never reads anything in between. Is this normal? (90, 305 TPI)

 

HELP!, I'm searching about EGR voltage range.

In my wife's V6 the min EGR voltage is 0.8 (MAP @ 44 kpa).

In my V6 the min. EGR voltage is 1.4 (& MAP @ 70 kpa).

I've vacuum leak . Cause could be EGR too many open?


Thanks in advance.

 

I removed my air tubes and going to install non-air headers.....the EGR is part of the emissions, right? Im not going to put that back on either, I should be fine as long as I disable it in the prom, correct?