Erik the Red
NAXJA Forum User
- Location
- Northern california
Thanks to an overzealous smog technician, my Comanche failed its smog test because there was no vacuum at the egr transducer. I had to take apart my egr and egr transducer circuit to clean out the little backpressure tube, which was clogged, and now I have to take my truck back to have it rechecked. Problem is, while the backpressure tube is now clear I'm worried the egr/transducer system is still not up to snuff.
My first question: is the egr valve open or closed at idle? It appears that the transducer actuates the egr valve (the valve stem pulls away from the manifold) when I rev the engine but then reverts once the engine attains the higher rpm. My question is, when exactly should the egr valve actuate? Should it open only while the engine is revved or should it also stay open at, say 2000-3000 rpm? Should it be open at idle? My Haynes and Chiltons manuals don't explain when precisely the egr valve should actuate.
What's so frustrating about this is that I live in an area of California where oxides of nitrogen aren't even tested for. My truck passed the emissions test...it failed the "functional" test because the technician took it upon himself to hook a mityvac to the transducer and found that it didn't have 5lbs of vacuum. Sheesh.
Any insight on this is much appreciated.
Erik
88 Comanche
4.0 engine
My first question: is the egr valve open or closed at idle? It appears that the transducer actuates the egr valve (the valve stem pulls away from the manifold) when I rev the engine but then reverts once the engine attains the higher rpm. My question is, when exactly should the egr valve actuate? Should it open only while the engine is revved or should it also stay open at, say 2000-3000 rpm? Should it be open at idle? My Haynes and Chiltons manuals don't explain when precisely the egr valve should actuate.
What's so frustrating about this is that I live in an area of California where oxides of nitrogen aren't even tested for. My truck passed the emissions test...it failed the "functional" test because the technician took it upon himself to hook a mityvac to the transducer and found that it didn't have 5lbs of vacuum. Sheesh.
Any insight on this is much appreciated.
Erik
88 Comanche
4.0 engine