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Old 08-11-2007, 01:13 PM
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Originally Posted by hon_jr
Wow! Okay, questions: what's an EFE, as listed on the diagram? That diagram looks like it might work, but it only shows the lefthand PCV valve. I assume the righthand one just tees in at the same point?

The Air Management Valve: is that for the smog pump? The smog pump and associated plumbing are missing, except for the righthand exhaust manifold still has the AIR tubes in place... I'm wondering what to do about this, too....

Actually, I won't know if that diagram works till I'm out in the heat (103 expected!) tomorrow. But the tubes that I have already identified appear to be the same configuration. What are the differences with the other 6 diagrams? And why so many configurations? Ergh.

Anyway, thanks for the help! And so fast, too! Dude!

EFE = Exhaust Fume Efficiency valve, also known as the heat riser valve on the right hand exhaust manifold. when cold, it keeps the right hand exhaust manifold closed to allow in speedy heating of the choke stove tube for the choke.

all of the vacuum diagrams i have show the PCV on the left hand side. either side doesnt matter, as long as its plumbed the same way as shown.

yes, the Air Management Valve is for the smog pump. its a valve that comes directly off one of the smog pump tubes. if youre missing some of the smog (A.I.R.) plumbing, you can either replace all of it (if emissions in your state require it to be there) or remove all of it and plug the exhaust manifolds with steel pipe plugs. a friend of mine has an 85ish Bonneville with a 305 and all of the smog equipment is capped off. it passed Texas emissions (which is only a visual inspection in my area) although for my car, they failed me for not having an EGR valve in place.

also, the EFE TVS and Purge TVS are Thermal Vacuum Switches, also known as ported vacuum switch. these are color specific as for what temperature they operate. through my own research, ive concluded that the Yellow = EFE, Purple = EGR, and Blue = Distributor.

as for the rest of the diagrams, they all look to be similar in routing, with only component location being different.

if you look at the upper left hand corner of the pic i posted, it says YCL. this is the emissions label identification. if you still have the original fan shroud, thats where the decal would be located. do you, by chance know what the code is for your vehicle ?

as for the diagrams, im getting them straight from my Chiltons manual for 78-87 GM midsize vehicles.

im glad i could be of assistance to you. holler back if you need more help.

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