EGR Valve Acting Strange *Pulled Codes*

Sorry, double post - my ISP hiccuped...

Code 33 - Insufficient EGR flow detected.
Look for vacuum leaks, cracked vacuum lines, failed EGR vacuum regulator. Check to see if you have 10” of vacuum at the EGR vacuum connection coming from the intake manifold. Look for electrical signal at the vacuum regulator solenoid valves located on the rear of the passenger side wheel well. Using a test light across the electrical connector, it should flicker as the electrical signal flickers. Remember that the computer does not source any power, but provides the ground necessary to complete the circuit. That means one side of the circuit will always be hot, and the other side will go to ground or below 1 volt as the computer switches on that circuit.
Check for resistance between the brown/lt green wire on the EGR sensor and pin 27 on the computer: you should have less than 1.5 ohm.
See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/


Diagram courtesy of Tmoss & Stang&2birds




http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

EGR test procedure courtesy of cjones

to check the EGR valve:
bring the engine to normal temp.
connect a vacuum pump to the EGR Valve
apply 5in vacuum to the valve.
if engine stumbled or died then EGR Valve and passage(there is a passageway through the heads and intake) are good.
if engine did NOT stumble or die then either the EGR Valve is bad and/or the passage is blocked.
if engine stumbled, connect vacuum gauge to the hose coming off of the EGR Valve
snap throttle to 2500 RPM (remember snap the throttle don't hold it there).
did the vacuum gauge show about 5in vacuum?

if not, check for manifold vacuum at the EGR vacuum valve.
if you have manifold vacuum then connect vacuum gauge to the EGR valve side of the vacuum valve and snap throttle to 2500 RPM.
should read about 5in vacuum

The operation of the EGR vacuum regulator can be checked by using a test light applied across the wiring connector. Jumper the computer into self test mode and turn the key on but do not start the engine. You will hear all the actuators (including the EVR vacuum regulator) cycle. Watch for the light to flicker: that means the computer has signaled the EGR vacuum regulator successfully.

savegoodautonfg said:

If i disconnect the plug that goes into the egr should anything happen while engine is running?

Click to expand...

No.

savegoodautonfg said:

Where can i buy the vacuum pump/vacuum test
Can you give me a link to a cheap one?

2 things jrichker,

if not, check for manifold vacuum at the EGR vacuum valve.
if you have manifold vacuum then connect vacuum gauge to the EGR valve side of the vacuum valve and snap throttle to 2500 RPM.
should read about 5in vacuum

Ok when it says manifold vacuum at egr vacuum valve, can you explain that a lil better?

vacuum gauge to the EGR valve side of the vacuum valve, can you explain that a lil better?

Click to expand...

As for vacuum a Mighty Vac is handy little tool. Most auto parts stores have them, and so does Harbor Freight Tools. However, I am cheap and usually use plain old engine vacuum & a vacuum gauge.

The idea is that you have engine vacuum at the input to the EVR regulator located on the passenger strut tower. Then you measure the vacuum on the output of the EVR to be sure you have 3-5" of vacuum when you goose the throttle up to 2500 RPM.