EGR Valve Question..Chasing a vacuum leak

[rollingbear]

Hay there,
I want to know is the EGR vacuum port supposed to leak down or hold vacuum? mine leaks down to 5psi fast then slowly to 0?? is it supposed to do that??


I am having a horrible time chasing a vacuum leak that flips my a/c dash vents. I have replaced all the vacuum lines i can touch. Seam sealed my vacuum canister, replaced a leaking iwe actuator on pass side, all the pcv elbows replaced, replaced the intake manifold gaskets and also water tested the intake manifold & not a drop..& i haven't found any new leaks. but i still have a p0171 and p0174 lean banks code and my dash vents still flip under load going up a hill. i just replaced a bad fuel pump when the code came on but i pulled and plugged the evap line and the dash vents still flip. its driving me crazy any help or advice
PS i plugged the EGR vac line & it still flips the a/c vents

 

[1955moose]

When I checked my Egr valve awhile back only 2000 5.4 expy, I used a vacuum pump and pumped to about 20 inches at valve and mine held. Usually if the valve doesn't hold you have a bad diaphragm in the valve. Guys am I correct on that test?


Sent from my iPhone using Tapatalk

 

[rollingbear]

Yes that's what i believe to be true.. that it should hold good vacuum.. i went to pick a part and i tested 3 of them and they all leaked down like that. I found one that held good vacuum for a minute and so i got it at pick a part.. but when i got it home and went to install it the next day it leaked down too.. and i was like WTH..so before i go buy a new one for 80 bucks i wanted to know if mine was still good or now.. maybe they were supposed to do that didn't know. but it still doesn't fix my main intake leak problem. I did the cigar smoke test and i can't see any leaks anywhere.

 

[1955moose]

Just had my good friend and master tech get back to me. He said yes the egr should hold vacuum, not drop. Oh by the way he has a 2000 expedition and a 2000 f150. I believe he should know. Looks like your gonna buy a new one!


Sent from my iPhone using Tapatalk

 

[rollingbear]

thank you for the reply.. its what i thought. bummer. & the suck thing is it still doesn't fix my main problem of the lean bank codes ..just a preferential problem.