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Ok, so I've done my reading and have hooked up the 5th and 6th ports using the tutorial from rotary resurrection.
My question is can I remove the original exhaust vacuum tube that was used to open the 5th and 6th ports?
The PO just left it hanging after putting an exhaust and it sort of fell off today from always scraping . I saw it hooked up to the back of the engine, so would i need to plug that up? It seems to be running fine and doesn't seem like there is a vacuum leak.
Guess I should mention that I have an S4 engine. Just wondering if I can remove the exhaust back pressure tube that once controlled the 5th and 6th ports???
IIRC the ports are controlled from a smaller tube coming off of the airpump tube going to the main cat and all this is one assy. I would remove the rubber hose that goes to the port actuators from this and cap the end of the hard line.
Was it just the rubber hose left hanging or the whole metal air supply tube going to the cat?
Sounds like it was left off of the catalytic converter. I would hook it all back up as it went with the exception of the vacuum hoses going to the port actuators. That should be a smaller metal tube coming off of the larger tube. I would cap it off with a rubber vacuum cap.
Search and download an FSM for your car so you can be sure where everything goes.
The operation of the port actuators with the airpump air is just something special on the FC and it may be just the S4 only. A lot of cars have pipes routing air from an airpump to the catalytic converter. Removing the air to the port actuators doesn't present any concerns as far as the rest of that system.
If you lost the whole metal air pipe, if I was not subject to emissions inspection, I would remove the air valve from the LIM and make or buy a block off plate and eliminate that and remove the air pump. That would clean everything up. I'm not sure about capping off the hose where the pump is trying to pump out air. I don't think they put out a lot of pressure but I'm not sure about doing that. I think I would do a little more work and clean things up a bit. I would check and make sure there isn't an open tube on the catalytic converter where the tube was supposed to go. If so that can be capped with a metal cap for it.
If removing the air valve on the LIM is more than you want to do right now you could look in to just removing the air pump and capping where the hose from it goes into the hard pipe near the engine. In the 3rd gen section IIRC there are some posts by Dale Clark on how and what to use for this type of cap. I think he used a furniture foot or something like that.
Whatever you do, I would check the catalytic converter to make sure that there is not an open port left on it.
I should of put more info in the OP. But the PO installed a exhaust, so I don't have the main converter which the metal tube hooked up to. That's why it was left dangling on the bottom of the car.
I'm using the air pump now to activate the 5th and 6th ports so taking that off is something I don't want to do.
I think I'm just going to put the rubber hose back on and see how much pressure is being released. Since it's just a vacuum port I think I might just plug it so I don't have to worry about dirt getting in.
On page 4A-60 of my 1988 FSM it states that the actuator starts to open at 1.2 psi and is fully open at 2.1 psi, this is for a S4 only. Might of changed for the S5.
I am into restoring my 1988 GXL, as I get ready to install my third engine I noticed a weird thing in my intake system.
The secondary intake ports are red and wet, any idea what caused this? The back of the secondary throttle valves are black and the red color goes from the throttle body through the upper and lower intake manifolds!
05-04-14, 09:23 PM
. I saw it hooked up to the back of the engine, so would i need to plug that up? It seems to be running fine and doesn't seem like there is a vacuum leak.
