Topic: EGR 403

[Rarebird]

Ok the missing pipe is for the heat cross over and it, the missing part, is connected to a temp/vac switch or delay valve ( which one I cant recall , Its been close to 12 years since I had my Olds Cutlass)  as for the Trans line it is for the modulator valve to assist in shifting  gears depending on engine load so it should be monitoring manifold vaccum or a port at the rear base of the carb... I have been racking my brain on how my Olds Cutlass was set up and  thats the best i can come up with. bigty88.... your pic helped a lot in recallling this thanks, But I would double check with the vaccum routing for a 403 Olds...just to make sure.
    As for the missing pipe piece you would be better off getting a new one they tend to rust very fast. I believe Classic / or Performance Years carry them  actually the entire set up, yes yours is rusted badly but the bolts are really not long and not that hard to remove if broken. If you remove the entire set up ( heat tube) use a good rust penatrating agent (PB Blast) a few times before attempting.

[John007]

Yes!!! already have a good rust lube on there.......Thanks!! I'll check those places out.........
.....................later......................

[Wook]

Here is the vacuum modulator hook up on mine...any manifold vacuum source will work.

[Wook]

Here are pics of the choke hot air tubes...arrows point to where the tubes end

[Wook]

For more intel, here's what the assembly looks like.  The two tubes and the loop section are separate and should come apart easily.  I found several at junkyards and picked the best setup.  Olds 350s also have the same tubing and are pretty easy to find.  Like rarebird said, hit them with PB blaster or something before loosening the bolts.  I haven't had any problems on any I've encountered yet. 

[ta78w72]

The other end of that choke tube connects to the screen on the underside of the air cleaner housing.  The only thing that does is pull filtered air through the tube to heat up the choke.  It's filtered because that air exits into the carburetor when it exits the choke.  If you connect it anywhere else, you'll get unfiltered air drawn into the carburetor.

[John007]

So that's what it looks like..... There great pic's really helps me a lot..........I was thinking that tube with the bracket was all one peaces.......

                Excellent............Thank You....................Later............

[John007]

I was mastaken that pipe which it connected to the choke does not go to the transmission but to the exhaust manifold........
Its either drilled into the exhaust manifold or just on attached to the side of the manifold definitely not a stock item.....

It looks like the pipe goes in to a half pipe which is clamp to the exhaust with a large pipe clamp.........

This is at the back of the engine on the pass side just before the exhaust manifold connects to the exhaust pipe......

Here are some pic, but its so hard to get to this area the pic are not  to good............





img]http://www.78ta.com/gallery2/main.php/d/12545-1/Image105.jpg[/img]



Why would someone have don this??

[ta78w72]

It looks like the end is plugged.  That wouldn't do much for heating the choke.

[Rick]

Why would someone have don this??

Back in the day, one of the popular swaps on engines was to take pre-emission intakes and put them on newer cars, to get rid of all the "stuff" that littered the under-hood view.  People in particular liked to get rid of their EGR valves.  The problem was that the "hot air" chokes were desireable because they worked better than the prior bimetallic strip controlled chokes.  But the manifolds without EGR didn't have provisions for the hot air choke.  The solution was to route the air going to the choke so that it came from a tube down on the exhaust manifold.  That way you still got "hot air" and the choke could still work, and you'd get rid of the ugly EGR valve and other stuff on your intake.

The setup didn't work nearly as good as the factory choke setup, but it worked.  What you show here is reminiscent of that kind of setup.  I'm going to guess that the loop behind that plate is burned through, and rather than do it right and replace it a previous owner just made up something that resembled the setup I described.  But that's just a guess -- there's no way to know for sure.

[John007]

So Rick!! what do you recommend??? Put it back to factory and cap that pipe..........The car still has the EGR on there, don't know if it works or not but i can get one that will...........Need to do something to pass this smog test............
Thank for that info........................Later...............

[Rick]

If you have a smog test to pass -- find a replacement for the part that goes into the exhaust crossover and put it back to the stock configuration.  Inspectors aren't hot on anything that's "rigged" under the hood.

[John007]

Ok!!!!!!!!!!! Got those parts today so I'll just cap it off and put back the factory stock............
...........................Thanks for all the help Guys.................
                                                                               Later.....................

[ta78w72]

Check your timing before you have it smogged.  That's the last test they do.  You can pass all the other tests but if your timing is off they fail you.

Make sure all your vacuum lines are connected, or at least like they look like they are all connected properly.  The technician won't really know.  He'll refer to the emissions sticker but won't trace all the lines.  One problem you could have is with the evap test.  They pressurize the gas tank to make sure it doesn't leak.  You'll need to have your canister set up properly because they pinch that line off to do the evap test.  If you fail the sniff test the most likely cause is the carburetor.  Good luck with everything.

[Maryland Bandit]

The U shaped piece is still availible from GM, as is the ? shaped one. Inline tube also carries the Z shaped and the ? shaped ones in stainless steel for the 403.