Like many of us, both of my XJS's have been victims of a previous owners attempt to affect repairs. As is too often the case, they had no idea what they were doing and many things are buggered.

Over the weekend I was working on my '90 trying to resolve a high idle issue. As I was going through the systems I have found missing parts, plugged vacuum hoses and butchered wiring. One by one I have restored the system back to original condition.

My current problem is the air pump system. The pump is still in place but the air switching valve, some of the hoses, and other incidentals are missing. I am now looking for these parts and then trying to figure out how/where they were originally mounted.

If anyone has an unmolested 90-91 V12 please let me know if you can send some pictures. I need to know where to mount the switching valve and how to connect the related hoses.

My distributor vacuum hose is also plugged off. From the diagrams I have seen I think it "t's" into the air pump circuit somewhere. Pictures and or detailed information would be very helpful.

Thank you!

Mark

PS. Feel free to post what atrocities a "PO" has done to your precious XJS.

 

I can't help with any air pump stuff as mine has none of that but the distributor will be Marelli and the hoses you refer to are ventilation, not vacuum. One runs to an elbow in the hose running under L/H intake manifold between AAV and air cleaner connection. The other runs out along the L/H fender brace terminating with an inline filter.
There should be a vacuum feed coming off the rear of R/H intake going to the Marelli computer though.

 

PO. Put a 'Leaper' in the middle of the Bonnet/Hood!

It just looks so awful that I am taking it off and having the hole welded up.

 

That Leaper is awful looking. I am willing to come by and help you take it off.

 

Truly a heinous act.

I'm sure the PO slapped that on the hood and proudly drove around thinking that it looked cool or classy. I can only imagine what he is driving today.

 

Here is a drawing of the Air Diverter Circuit;




My XJS missing many of these valves and hoses. Hopefully I will be able to replace these parts soon and get the air injection system working properly.

Mark

 

Who puts it on the center of hood? Personally I like leapers but not there.

 

If I didn't need the money to buy Petrol, I might have even treated you to a ticket.

 

I think I know what he isn't driving.

One of the Sexiest Sports Cars on the Planet!

 

Thanks to David at EverydayXJ, the parts I need to restore my air pump system are on the way. As I sifted through the previous owners handiwork I had to figure out what was missing and how to make it right.

I could not find the end of the pipe that goes from the diverter valve up to the air injection tubes. As I looked around I noticed a rubber hose duct taped to a metal tube. Unraveling the tape revealed the end of the air pipe and the rubber hose stuck into a hole in the air pump mounting bracket. I don't know why they bothered to do this. Without pressure from the air pump I doubt any air was going into the exhaust. No wonder it wont pass emissions.

Don't get me wrong, I like duct tape. It can be very versatile and useful in an emergency situation. However, one place it does not belong is doing permanent/long-term auto repairs.

Fortunately I think that is the last of the previous owners work that I need to restore. After that it will be working with standard British engineering. (A whole other kind of fun!)

Mark

 

Another new development....

As I was inspecting and replacing vacuum hoses today I found that the hose going from one of the fuel regulators to the intake manifold was full of fuel. It appears that the diaphragm had failed and was drawing raw fuel into the intake. Another reason why the car would not pass emissions and I'm sure that side of the engine was running rich. Assuming that the O2 sensor are still working, the ECU would be trying to manage that condition.

I replaced the regulator today. Once I get the air pump system working properly I'm confident that the engine will run much better and will pass emissions. I'm just hoping the cats are still ok.

Mark

 

OMG! That is the worst mod I have ever seen done to a Jag!

How could someone do that to their Jag?

I hope the dealer didn't do it for him.

Maybe he was near-sighted and couldn't see it if it was at the front of the hood, lol!

Vector

 

I could be wrong !!.....But l believe that that leaper is in the position that the European law of the time allowed. Putting them (as mine is), at the front is very strongly frowned upon by the law, pedestrians and cyclists. Just the same as they banned all the 4x4s with big metal nudge bars on the front in Europe, only soft plastic fake ones allowed now.

 

Sounds like you and I own the same car or had the same previous owner LOL.

 

Hi Vector

It does look like it was fitted by the dealership, as it has been done in a very professional way, with all the proper backing plates etc.

But even so it doesn't detract from the fact that it looks blinking awful!

Though I think I can work out the reason for putting it on.

Namely being a 'Grey' XJS its a very good match for the 'Curb' on the side of the road, so having the 'Leaper' where it is, gives you a very good aiming mark for the halfway point on the bonnet/hood.

A little bit like the 'Three pointed Star' on my Merc.

While I have to admit I've found it very useful for that purpose, as the bonnet/hood and the Curbside tend to blend, I also know that if you can't manage without it, then you shouldn't be driving on the road.

 

That's quite possible Malc

 

Hi Shane

I think that your 'Leaper' is in a better position, if it has a round base (which mine doesn't have) you might be able to swap it for a 'Growler'

Why do they put this stuff on there? how can you improve on perfection?

 

Now I'm starting to work on the new-to-me green '89.

The first two problems provided by the PO was the installation of a battery cut-off switch because of a voltage drain that was killing the battery and a switch that was mounted under the dash to turn on the AC compressor.

It seems that the compressor stopped working so the PO installed a switch to provide power to the clutch. He did not know about the fuse in the engine bay that feeds the AC relay. Sure enough the fuse was blown. I replaced it and now the compressor has power as it should.

The PO went to a lot of trouble to bypass the existing wiring instead of just fixing the real problem. A simple fuse replacement.

Fortunately most of the rest of the car is still in original condition except for an aftermarket radio. I will restore that back to original as soon as I find an AJ8700.

Mark

 

Leapers!!!! The last of a great tradition. First, it was styled radiator caps. The MOtometers with temperature gauges and fanciful wings. then as the filler went into the engine bay came the hood ornaments. The Flying Goddess of RR fame, the Cormorant, improperly referred to as a Swan of Packard fame.
and many more.


Too bad.


I wish I could find one like the original Jeep in the Popeye comics.


But, if an other wise unwanted leaper came my way, it just might find a new home
front and center on my Jeep's hood/bonnet.


Yeah, in my wild youth, I removed the ornamets from my 47 ford and 49 Mercury. Dechroming was fashionable....


Carl

 

The PO installed the a/c compressor switch for the wrong reason but it is not such a bad idea to install a switch anyway. The compressor normally runs whenever the fan switch is on regardless of whether you want heat or cold.
Switch can be easily hidden and must surely reduce unnecessary wear and tear on the system.