[LYVFD8142]

To fix code 33 try the following using the Haynes manual:

1) Remove the EVP sensor from the EGR and test the EVP, if tested bad replace the EVP.
2) Spray a little lub inside the EGR valve on the wall and then use a screw driver and put it through one of the holes in the bottom of the EGR and push up (not the hard). If it's stuck that should free it up.
3) Put the EVP sensor back on the EGR and test the EGR by applying vacuum on the EGR. You should hear the plate inside the EGR move. If it still fails you may need to replace the EGR valve if still testing bad.

Thanks to Steve83 with helping me fix that yesterday.

To fix code 51 just replace the ECT sensor. The ECT is located right above the water pump and uses a 1" deep socket to remove. Have the new ECT ready with the tape on the threads because once you remove the old one radiator fluid will start pouring out, have quick hands and you can replace it with minimal lose of fluid.

To fix code 67 push the clutch in when doing the test. Make sure you chalk the tires.

 

[LYVFD8142]

I was thinking 67 was the clutch code, a friend was trying to do the test and he forgot to push his clutch in when doing it.

The ECT on my 89 is by the distributor in the center of the motor (up front). It has a connector with 2 wires going to it.

 

[LYVFD8142]

I will try and take you a picture of where mine was located so you can see if it matches up to yours.

 

[LYVFD8142]

The ECT sensor (device that connects to the EEC unit) is different than the temperature sending unit (Temp gauge in dash). The ECT can affect the idle if the EEC computer thanks its running to hot then it may adjust the timing to try and cool itself down.

Tell the auto part monkey that you need the ECT sensor, it will have a plug with 2 prongs inside of it.(ECT sensor and Temperature Sending Unit - Temp gauge)

 

[LYVFD8142]

Pictures will help out a lot. I will try and look at mine tonight when I get home as well.

 

[LYVFD8142]

The EGR code 33 is pretty simple to check using the Haynes manual, your checking to see if you have +5v and the checking the ohms across 2 pins. More than likely yours did the same thing as mine and the diaphragm inside the EGR valve got stuck. I was able to push on it with a screw driver from the holes on the bottom of the valve (you don't need to take it off).