scottpeterd

Hi,

I have what I think is an EGR on my 1979. It's on the back of the block, on the passenger side.




It does not look like the EGR listed at AutoAtlanta.

The pic shows where it connects to a port on the rear of the head. The pipe at the bottom goes to a similar connection on the other head.

I would like to delete it. There are no vacuum lines running to it.

The 'diagragm' at top is leaking what appears to be exhaust.

Does anyone know what this piece is? And the easiest way to delete it?

Cheers

Ducman82

One way valve for the air pump. We don't have EGR on our cars

linderpat

Hey, those are my initials. I am not on your car

As Ducman said, not me, er I mean EGR. however you can delete it and the whole airpump system, and just cap it off. Use a 21" fan belt to substitute for the air pump delete.

scottpeterd

That makes more sense to me. While playing around, I have found an EGR valve. It's another system.

i have been wanting to get rid of the air pump. I've just yesterday deleting the air pump on my 1992 XJS V12. What a pain that was, as I had to fabricate 12 block off plates and fabricate and idler pulley (on the V12, the A/C compressor is fixed in the V of the block, and the air pump is the tensioner for it's belt).

But, I'm stumped as to how this one is supposed to work. There are only two connections to this valve. One runs forward into the back of the passenger cylinder head, the one from the bottom runs to the back of the driver's cylinder head. Nothing connects to the head of this unit (where it looks like the diagraphm sits.

Where is the air pumped into?

Do you know what size plugs I would need to seal off the back of the heads?

Cheers

Ducman82

The air pump, pumps the air in to that one way valve, then the air goes to the exhaust ports on the back of each head. best way to delete is to remove the piping and plug the ports at the head.

The Forgotten On

78-79 has EGR, 80-95 does not. It gets exhaust gasses from the right side exhaust manifold and plumbs it up to some diaphragms like the one posted above.

Rob Edwards

Yep, here's the theory of operation of the EGR valve



And the EGR valve actuation with vacuum applied:

Ducman82

so CIS cars had EGR? wow. where does the valve bolt too? how is it feed in to the intake tract?

V2Rocket

You've got a V12 Jag and a 928 in Uganda?
Would love some scenery shots with those two.

Rob Edwards

Like this. Dumps into the passenger side of the plenum, and there's a 90 degree bend inside that points it to the rear of the plenum.

scottpeterd

This is great guys..

Spencer: One of my jags is stateside. I've got a XJS convertible sportpak model in the Olympic Peninsula. That one i use for the summer when I'm living on my sailboat on the Puget Sound

I've got another XJS coupe in Uganda. That's for fun weekends. It keeps my S600 (another V12) Mercedes company. The jag is much more fun on our roads there then the S600. The S600 I keeped parked at my marina there. I live on my other sailboat on Lake Victoria about 4-5 months out of the year (when it's winter here in the states).

My 928 lives in Baltimore. I brought that from Vancouver to Baltimore 1 1/2 years ago. Did 7000 miles non-stop from Van to Mexico, then up through the US desert and into the Dakotas, and on to Maryland. Did it with only one breakdown (the headlight relay gave up in the desert outside of Taos at 3am). Best roadtrip I've ever had! I only get to drive it about a week or so a year.

Rob:

That picture is perfect, and explains my problem. The top half of my one-way valve for the air injection system is missing! Hard to tell from my picture. Something from a previous owner I suspect, unless they are prone to just falling off on their own! It's leaking at the diapragm, and it's pretty noisy. Sounds just like a leaking exhaust (for obvious reasons).

That's the one I'd like to delete. I need to find out the thread size in the block where the pipes enter so I can remove it and block it.

Thanks for all the help. Like I said, I only get to drive the 928 about a week or so a year. I really dislike having too much shop time with it (although it is fun to work on).

Cheers

V2Rocket

god, what a fleet, and what a life to have!

scottpeterd

Quick update, as I am finally back on the east coast to work on the 928

I managed to get the air tube fittings off the back of the head.

For anyone else interested, they are 16mx1.5.

I found these fittings at my local hose fabricator. They are adapters, not plugs, so they need to have a plug fitted at the other end.

crushingday

Where in Baltimore are you? I am in Towson

-Ross

scottpeterd

Ross,

I'm in Overlea, south of the Beltway. I'm working on the car this morning if you find yourself free