7_Zero

Car has been throwing fault code 33 for some time now (EGR did not open/ respond during test or if memory code, did not open intermittently - EVP EVR PFE). As far as I can tell the EGR valve is good, I applied vacuum to it and the diaphram opened up and the car stuttered. I know that there is vacuum to the EVR solenoid, but it doesn't get past the solenoid. I have pulled the solenoid off and tested it, one of the lines I can blow through whether the solenoid is on or off as it seems to bleed to the adjacent solenoid. The other line I cannot blow any air through it unless power is applied to the solenoid. Once power is applied air will pass through, however with some difficulty. The instructions on how to test the EVR has gotten me confused. Hopefully someone can help make sense of this.


Aren't the last two lines contradicting themselves? If air does not pass through then it is good, if air does not pass through then it is bad. This doesn't make sense.

Before I have to go and shell out $ for a new EVR, how do I know if it is an EVR problem or if it is something to do with the ECM?

Thanks for your input!

sleeper_inc

I believe its trying to say, that if air passes through with no power then its bad, but if air passes through with power applied it's fine. The only way to know if its the computer or not is to hook a volt meter up to the lines and have the volt meter able to be seen inside the car and go for a drive... If you see voltage then the computer is doing fine (after driving for 10-15 minutes on the high way) if you see no voltage then either the wiring is bad or you connected the voltmeter wrong.

Also, if this code popped up when you where KOER testing then its because the engine was cold I bet. So the code would mean nothing.

speedjunkie92

fault code 33? egr not opening properly

7_Zero

Ok, I lied, it is actually code 34, pretty much the same thing. I attached a vacuum gauge to the solenoid and went for a drive, still nothing. I will have to see what I can rig up with my volt meter. I know that the engine is warm enough as I have pulled this code everytime I ran the test and the engine temp was 175-200 degrees. That and the car didn't pass emissions last time.

speedjunkie92

ok so its EGR not opening properly test condition (R), or insufficent flow of EVP voltage high (sonic) or PFE sensor voltage high or out of specification test condition (O, R, C)

7_Zero

Thanks for the tip with the voltage meter. I unplugged the connector to the solenoid and back probed it. I received a constant 12-13V, figured that couldn't be right so I plugged the connector back into the solenoid and results were much better. After driving for about 15 minutes with the temp at about 150-160 I got blips of .04-.27V with 2V spikes durring slight acceleration. After about 20 minutes I started getting readings from 2V-7.8V during accelerations and going up slight inclines, and upon WOT received 0V like it should, so the computer must be working properly. While at the highest voltage rating of 7.8 it still showed no sign of vacuum at all, so even though I can blow air through the solenoid, it must have too much resistance.

I also applied power to the solenoid while the car was idling and still didn't have any vacuum past the solenoid. I guess I will check the JY.

Thanks again for your help.

mg man 75

Here is info on codes but looks like you know them. Some other may need this.
http://zenseeker.net/4x4/eec_iv_2_digit_codes.htm
How to test system. http://rothfam.com/svo/reference/sensors.pdf
Here is 88 service info. May add more info
http://www.rothfam.com/svo/reference/volumeH/1988/

edzdallas79

um, i would just replace the regulator. i got one for $12 at autozone and it took all of 5 minutes to change and it solved my problem when i had a similar code (but a 3 digit one saying the egr valve wasn't opening)

7_Zero

Do explain if you would, what regulator are you talking about?

edzdallas79

my bad. I meant the solenoid. on mine, the solenoid wasn't opening to send vacuum to the egr valve.

I tried to find info on how to test the regulator which if I remember right was on the top of the valve, but I think I was too confused to do it.