Testing EGR Valve
 

Hello all,
1993 2.2, did not pass smog for High NOx, tech says could be EGR. The car has 213K and have never done any maint on the EGR in terms of cleaning ports or replace EGR valve.

Question: I put a hand vac pump on the EGR port and try to hold vac at 10 in.HG to see if the diaphragm will actuate but nothing. Wont hold Vac.

Does this indicate torn diaphragm and the EGR needs to be replaced, or will a good cleaning of the EGR valve body itself maybe fix it to working condition.

thx
bw

You can pull the valve off and check the ports, if the ports are clear and the valve pintle lifts when you apply vacuum, then you have a control issue...this system has a lift position sensor and a solenoid valve controlling it.

Thx, pulled the EGR, when apply vac the valve pintle lifts and then retracts right away. Is this normal? There is a lot of soot that I will clean out but it seems to move freely. Can the sensor be checked? or replaced separately. It appears that the only way to change the sensor is to buy a new Valve. When you say control issue, dose this mean that if the ports, runners are clogged then this contributing to the problem?

thx
Bw

if you apply vacuum and the valve lifts and then loses vacuum and drops right away, the valve is bad. clean the ports while you're at it as well.

by control, i'm referring to the ecm, but your valve is bad, so it needs to be addressed first anyway.

Thanks for the reply Dr. If I plug both openings on the ERG on the bench it holds vacuum. Are you saying that it should hold VAC with the ports open to atmosphere?

thx
Bw

i'm fairly sure the valve is bad, but send me your email and i'll get you the specific diagnostic procedure...it's pretty straight forward and we won't be guessing.

I cant find anywhere on the forum to send you a private message

click on my screen name and it will give you the option of send a pm

Sounds like it.