Plug for '79 SC EGR Airbox Hole

[OsoMoore]

When I removed my CIS on my SC without an engine drop, the worst part was getting the EGR valve off, and the intake runner bolt behind it. When I put it back together, I would like to leave the EGR valve in a box for some future poor soul.

The pipe to the exhaust was already capped by a previous owner, and I can easily cap the vacuum intakes on the throttle body. But I'm not sure how to best cap the airbox hole. I'm looking for any bright ideas, or possible sources of a plug that will fit it tightly.

[timmy2]

PM Tony, he may have one from an old Airbox kicking around to measure for you.
(Boyt911sc)

[timmy2]

Or just take the airbox to the hardware store and find a plug.

[OsoMoore]

The 15mm hole is looking fairly difficult to plug cleanly. It is all metal at it's opening. Maybe I can epoxy something across it, and assume that it will be drilled through safely by someone eventually wanting the hole back?

I'm close to just putting the EGR back in, and all the attendant cursing during CIS reinstallation.

[boyt911sc]

Originally Posted by OsoMoore

When I removed my CIS on my SC without an engine drop, the worst part was getting the EGR valve off, and the intake runner bolt behind it. When I put it back together, I would like to leave the EGR valve in a box for some future poor soul.

The pipe to the exhaust was already capped by a previous owner, and I can easily cap the vacuum intakes on the throttle body. But I'm not sure how to best cap the airbox hole. I'm looking for any bright ideas, or possible sources of a plug that will fit it tightly.

OsoMoore,

Could you post some pictures where you want to cap the air box? Thanks.

Tony

[timmy2]

I believe it is the hole under the air flow meter area on the vacuum chamber section of the Airbox in the squared off area around the corner from the CSV. (If that makes sense to you)
Mine has a factory plug there.

[OsoMoore]

Originally Posted by boyt911sc

OsoMoore,

Could you post some pictures where you want to cap the air box? Thanks.

Tony

I'll see if I can upload one tomorrow. Phone doesn't want to attach pics.

[boyt911sc]

Originally Posted by OsoMoore

I'll see if I can upload one tomorrow. Phone doesn't want to attach pics.

I was directed by Dennis' post and checked the early CIS air box in the garage. Find a threaded plug and use an o-ring to seal the opening. I might have something lying around.

Tony

[OsoMoore]

Here is where the EGR hole is located. A threaded plug is not effective because the hole is not threaded, and the hole is metal inset into the plastic of the airbox. I ended up putting back the EGR. It wasn't as bad once I had sleep, time, and lots of careful study.

I still hate the EGR.

[boyt911sc]

It has been a long time since I touched or seen an EGR for 911. How is the metal tube secured to the air box? This could not be simply plugged (?) or it would leak. Do you have a picture of the tube end (fitting if any) from the EGR? I have an EGR some where in my garage and will see what I find out.

Tony

[fanaudical]

I'm pretty sure that at the base of that pipe where it connects to the airbox you'll find a threaded fitting with an ID that matches the pipe. (The pipe goes through the fitting.) If you remove that fitting, I think you then find a steel washer and silicone bushing. Tightening the fitting into the airbox compresses the washer and silicone bushing, thus sealing around the pipe.

Couple of suggestions to plug this:

- Find a threaded plug with similar threads as the fitting.
- Use existing fitting but replace washer with solid disk.
- Thread the ID of the fitting and install a plug in it, replace the fitting.

[OsoMoore]

Back here again and still hate this thing.

I'll try fanaudical's idea about checking the other end of the pipe.

[boyt911sc]

What do you need? It has been 10 years since you posted this problem. Do you need the big plug to seal the air box?

Tony

[OsoMoore]

Originally Posted by boyt911sc

What do you need? It has been 10 years since you posted this problem. Do you need the big plug to seal the air box?

Tony

Had to take apart the CIS again to clean junk out while rebuilding the engine. So now I'm curing the EGR system again, and I have to wait for shipping for some new sleeves and injector stuff.

So I'm thinking of trying to plug it again. Although I could just put the EGR back in. I suspect I'm getting a little unmetered air around the EGR pipe, but it was running well enough.

[Aztim]

I used this plug and it was a perfect fit, found it at a pep Boys

[OsoMoore]

Originally Posted by Aztim

I used this plug and it was a perfect fit, found it at a pep Boys

Did you have to cut a thread, or was the metal soft enough to just run it in without doing that?

[Aztim]

Im starting to think the airbox on my 76 is different, mine was already threaded