Kevin84Z28

iTrader: (3)

I'd appreciate it if someone could post up a picture of a carburated L69 or LG4 smog diverter valve set up. It's that big dumb black chunk of plastic that's attached to the right side (passenger) of the motor, behind the alternator. I took mine apart to put my headers on and I want to make sure I have the hoses on correctly. Not too long ago I had to buy the diverter valve at $450 so I don't want to mess it up. There are a lot of pictures posted of stock L69's, but that darn intake hose covers the area I need to see.

69-er

I just happen to have my 83 L69 out on the floor waiting to go back in my car. See if these pictures will help. It's all original except the metal pipe to the catalytic converter got corroded next to nothing years ago and I had to splice in a piece of vacuum hose to the diverter.

69-er

More...

69-er

Last ones...

Kevin84Z28

iTrader: (3)

Thanks, thats a huge help. I also got my hands on the GM shop manual. I redid one of your pictures the way it shows for an 84. When you said your tube to the cat corroded, did you then attach the cat hose to the rear air tube? Thats very clever, I would have never thought of that. You'll see that I cut and pasted another air valve on the cat tube. Mine does have that.

Kevin84Z28

iTrader: (3)

On closer inspection of that picture, is the A.I.R. tube just hiding behind the hose that goes to the cat? I didn't realize until I after I posted that picture. Take care of that air diverter valve. My auto parts guy gave it to me for $450, but it lists through the dealer at $680. At NAPA it was $580.

Dens71TA

iTrader: (5)

The top two ports(in a V-shape) are for the right and left exhaust manifolds, the port on the front is for the air pump muffler when air is diverted to atmosphere, and the port on the back is for the converter.

Did you also replace the check valves on the air tubes? What kills the diverter valve is that the check valves start to leak and let moisture back flow up into the A.I.R system and rust up the diverter valve and pump. I don't know why they didn't use stainless steel peices in the diverter valve. Then it would never be a problem.

Kevin84Z28

iTrader: (3)

I replaced two of the three. They didn't use stainless steel because of $$$$$ That could add $15.00 build cost to each vehicle. 240,000 vehicles per year times $15.00 = $3,000,000. And thats just that part. Thats how they come up with the bottom line. Cheap parts where they can, hold off on upgrades. In addition, they do make a good portion of their profits on new parts. Do you think they have the technology to make a lightbulb last a lifetime, they do....

69-er

Yeah, that A.I.R. tube comes out of the A.I.R. manifold right behind the CAT hose.

I just left that line to the CAT disconnected as the pump froze up long before. Not long after I bought the car, I had to replace both A.I.R. manifolds due to complete rust-through. I also replaced the check valves.

Some time around the pump freeze-up, the CAT tube then corroded away. You can also see the top of diverter valve also corroding away. I even live in the Southwest, so I was surprised to see this corrosion.

I've also been looking for a used diverter in case I ever get the system working again. Those prices are outrageous!

Kevin84Z28

iTrader: (3)

Is there a way to tell if a used diverter valve is operable? I guess you'ed have to have some sort of 12v system where you could activate the solenoids to see if they operate. There's no way to open it up and keep it working.

Dens71TA

iTrader: (5)

Yes. You need to remove the solenoids and use a mechanics hand vacuum pump to see if the valves move. The valve for diverting air to atmosphere is usually OK because the ECM typically commands that mode when the engine is above 1500 RPM and won't allow the corrosive engine exhaust to back flow farther into the system. The valve for switching air from the manifolds to the converter is almost always locked up. You can remove the lower diaphram housing by cutting the metal band. I've got a few working again with some penitrating oil.

The solenoids can be tested with a battery charger. They are low current/heavy duty units so they rarely go bad.