New manifold/pipe questions

[84eaglelmz]

So it doesnt matter if it works? It wont ruin the engine like the book says? Lol in NY i do not need a visual inspection of emmision anything. Last time i got it inspected they looked at te lights and wipers and passed it.

[captspillane]

No it will not ruin the engine. The idea is that it will recirculate a portion of the unburned fuel left in the exhaust back into the engine in hopes of releasing less hydrocarbons into the atmosphere. It is designed to save a very tiny amount of fuel economy if it works well. It makes your car run extremely poorly if its stuck open. It has such a tiny effect that it won't be noticeable if it its stuck shut. The vaccuum line to the EGR is just one more vacuum line that could pop off or leak and drastically affect your carb.

Most people value the lack of complexity and clutter much more than the miniscule positive effect it could have if it worked. You won't have unburned fuel in the first place if your carb gets the mixture right. You won't need one at all, even legally, if you have a TBI because then the computer uses a O2 sensor to correct wrong fuel mixtures, leaving the EGR obsolete.

[carnuck]

The EGR's job is to cut NOx by cutting the combustion temps. It does it by putting exhaust gas back in to take the place of oxygen rich atmosphere. The NOx becomes ping when it gets too high. Jeep overcame the need for the EGR when the HO came out by retarding the Renix cam (which cuts VE or volumetric efficiency) and cuts NOx. It also pushes the power band to higher RPM which is partly how the HO makes more power than the Renix.

[84eaglelmz]

Oh ok good, because I'm sure it hasn't worked since most likely since reagan was in office. another quick question, what are them two ports on the air cleaner underneath? that look like elbow tubes, they are capped on my eagle

[doc65]

Those are for the "Pulse Air Injection" system.

[84eaglelmz]

Thanks! I think ill just plug the hole for the egr then. Anything else important to know before replacing the manifold?

[BenM]

Go slow and torque evenly, then retorque after a few miles. Four or five short wobble extensions will help you. Save those washers, they're important.

Put a stud in the bottom rear hole where the bolt is probably missing. There should be a front stud too. It helps hold things in place while you're fitting.

Hook the exhaust pipe up last so it doesn't pull on the manifold. You can get brass nuts that are less prone to seizing, use anti-seize either way.

There's a hole in the lower arm that will let you get the socket and a long extension right on to the front bolt for the exhaust pipe. The back one is a little harder to get to, but easiest from underneath. Without a donut, I like a little exhaust sealer on the connection if I'm re-using the pipes, the heat hardens the metal and makes a seal more difficult.

Watch the connectors on the intake gasket, sometimes they interfere with the exhaust runners and will cause a leak. I like to use Copper gasket sealer on my gasket set, and let everything sit a while assembled, then warm up the engine easily and check the bolts.

Technically, if everything is flat, you don't need the exhaust gasket, the factory never used one. I always have.

[84eaglelmz]

Thanks. Next free time i get ill pull it in the garage and see what ill do. First thing will be clamps or some chinese vice grips