Hey,

Had a new cat and muffler welded in to the 84 SE the other day. This was the first really good look at the underside of the car. There are two "UFO" hoses I need to identify. Maybe someone just knows by description. I can supply photos.

One hose is on the passenger side. It looked like about 1/2 inch ID (I have not measured it yet). It comes off the side of the block and starts down toward the underside of the car. Apparently the PO must have decided that this was not needed, because it appears to have been cut off. It is not the crankcase breather. Further, there is a capped off pipe extending from the side of the new cat which looks suspiciously like a candidate for this hose to connect. Sound familiar to anyone?

My other UFO is a much smaller diameter hose hanging down in the same passenger side area. This looks about the size of a vacuum line. It has a small hose clamp still attached. Nobody seems to know where this one connects either. I have not been able to find a good photo of another car anywhere, and I don't have access to a similar car to look at for comparison. Any suggestions please?

 

The first one sounds like the hose from the Air Control Valve (ACV), it helps emissions by diverting air to the cat to help burn up the leftover gases. The ACV is on the passenger side, below the carb. It's not necessary but will help stop popping backfire.

The second one, I'm wouldn't know without a pic.

 

They are both probably for the same thing,air injection into the exhaust.

The big line feeds to the big main cat.
The small line feeds to between the 2 factory precats.Only the 84-85 cars had the smaller air injection line,because they had a pair of smaller precats.The earlier cars had only 1 precat,or no cats at all on the 79-80 cars.

Do you still have the 2 small precats,immediately after the exhaust manifold?If not,then the smaller line serves no function and you can probably just leave it be,or tuck it aside so the smog police dont spot it.I wouldnt cap it off,since that line will still be flowing air at certain times,when the ACV decides its neccesary.

 

The smaller line you are refeering to or vacuum hose is the hose for the 6 port actuators. Without this hooked on the small pipe the actuators will not operate.

 

If the small black hse for the aux/6-ports has been off long, then they are most likey frozen and non-op from carbon buildup. Now the fun begins taking the intake off and cleaning them up.

 

Yea hey guys i got an 83 FB base model 12A I just bought the car had it for about 2 or 3 weeks now and The previous owner had a aftermarket Cat welded in with no inlet for the hose that runs from the lower passenger side by the exhaust manifold on the engine to the cat.....so the hose is just there could this be the reason way my car makes poping farting back firing noises from the engine compartment area(it sounds like) if so I how can I stop it? can I just plug the hose? or cut a hole in the side of the cat and weld on a metal tube on to it and connect the hose to it? HELP!!!! A Rotary sound not have such a Disgraceful sound!!!

 

I am in Florida until Monday and the car is up in NY. I can't recall for sure whether there are pre-cats, but I think there are. I will check this as soon as I get home and write back.

 

Another thing that will need attention on this car is the idle speed. Right now it is consistent at 1500 RPM on the dash tach. The idle is smooth and does not break up, but it's pretty high compares to the target of 800 RPM that I read about in another thread. Could the actuators you refer to be contributing to this? Maybe solving this hose will carry an added benefit of curbing the idle. Wishful thinking anyway.

 

Sorry, but no. The aux ports control the internal disperssion of air/fuel. It does not affect idle.

 

OK, well I won't hold out any hope for that miracle. There is a really nice thread about settling the idle speed down so I'll just work off that for this issue. Thanks for the response.