I've got the air pump off. Didn't put an idle pulley in yet, just took the A/C belt off...wont need that for several months.

I've got cold air routed to the intake manifold, but am not sure of what hoses to keep that use to go to the back of the airboxes, and which ones to plug.

I would think one of these connections recirculates vapors from the crankcase and are going to result in a mess if I don't vent them back into the intake (and I'm thinking this is the large rubber connection just forward of the oil cap on the left side (as viewed from inside the car looking forward). Or can this connection be safely capped off?

Is there a good site describing what I can take off (air rails etc) without pulling off something vital?

Thanks!

John

 

You are smart to be cautious rather than simply going hog wild and ripping things out.

I'm not personally aware of a site that specifically has the info you need.

Kirby's book will provide lots of info and I suggest the factory service and parts manuals to *first* identify all of the many vacuum operated devices and then research/discuss from there.

Much of the "stuff" you see is related to ignition vacuum advance. It's a complicated system. Some guys ditch the whole thing with varied end results. This is an entire discussion itself.

As far as crankcase venting goes read the info in Kirby's book. The PCV valve system/operation is a bit unique but I can't remember the details.

I assume you're working on an 80s-90s vintage V12? You didn't mention.

Others (hopefully with better memory banks) will chime in but I sorta doubt that anyone will have an exact prescribed list of what to keep and what to eliminate.

Cheers
DD

 

If your state does not inspect emissions systems you can safely remove the air pump, air rails and associated plumbing. My air pump failed and the check valve was leaking too. I decided to remove the system and I fitted an idler in it's place. You block off the air tube fittings in the intake manifold. There have been many discussions about what to use. I just tapped my intake to accept bolts with a washer.

If you are removing the stock air cleaners for some noise makers make sure you do NOT block off the PCV system on the left air filter housing. You need to have a very slight vacuum on the crankcase at all times. So if you ditch the factory setup you will have to create your own. To see if it is working you can rig a vacuum gauge on the dipstick tube. .5-1 inhg of vacuum is ideal.

 

Hey guys thanks for the input. I did add "cold air" inlets, did block off the PVC and crankcase vents, and quickly discovered what a mistake that was! So a little more plumbing and I'll have that issue rectified.

Question about tapping the intakes...were you concerned that some excess metal from the tapping might find its way into the engine? I've not yet examined how the air rails are attached, so maybe it's not an issue.

I do have a vacuum gauge, so will put it to good use as suggested.

No, my state (Indiana) does not inspect emissions, or anything else for that matter. They had a go at it maybe 30 or so years ago, but the system proved so corrupt (I think a $20 passed quickly from the motorist to the inspector was the going rate) that the state gave up on it and has not looked back.

John

 

Check out Ed Sowell's and Bernard Embden's websites. Just google their name and "Jaguar". Both sites have many photo-documented writeups of lots of different procedures. One of them has a photo essay on blocking off the air rail ports without it being permanent, in case you end up selling the car to someone in another state.
This method does notnolve tapping the ports.

 

I tapped my intake while the manifold was off the car. However you can do in place since the ports lead to the exhaust not internal engine. If you want to catch as many chips as possible put grease on the tap.