Air Injection system question on 95 XJS with 4.0
#1
12-02-2011, 12:48 PM
Air Injection system question on 95 XJS with 4.0
I am trying to sort out some Air Injection OBD codes and read this in Kirby Palm's XJS Help guide:
Can someone point me to where the air rail tubes are on the 4.0?
"GETTING THE AIR INJECTION SYSTEM TO ACTUALLY WORK: John Napoli adds, “I have had the opportunity
to see the air rails from Jag engines -- both 6 and 12 cylinder versions. Very often, the cars have brand new air pumps
and diverter valves and hoses -- so someone spent a good penny replacing all that stuff. And on every one, the air rail
tubes (where they stick into the head) were completely coked up. You would need some really ambitious air to get
through all this!! Moral of the story: if you are going to maintain your air pump system, don’t forget to do the obvious
and simple and remove and clean out the air rail tubes. Otherwise you are just wasting time and money.”
You’ll also probably need to clear out the passages within the heads. There’s nothing complicated about those
passageways, they are straight shots into the exhaust ports. You can clear them out with a drill."
to see the air rails from Jag engines -- both 6 and 12 cylinder versions. Very often, the cars have brand new air pumps
and diverter valves and hoses -- so someone spent a good penny replacing all that stuff. And on every one, the air rail
tubes (where they stick into the head) were completely coked up. You would need some really ambitious air to get
through all this!! Moral of the story: if you are going to maintain your air pump system, don’t forget to do the obvious
and simple and remove and clean out the air rail tubes. Otherwise you are just wasting time and money.”
You’ll also probably need to clear out the passages within the heads. There’s nothing complicated about those
passageways, they are straight shots into the exhaust ports. You can clear them out with a drill."
#2
12-02-2011, 02:13 PM
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If the air injection installation on your 4.0 XJS is the same as my 4.0 XJR....and I suspect it is...you're looking for a hose/pipe coming off the air pump and which eventually branches into two tubes going directly to the two exhaust manifolds.
The older systems were plumbed differently with a separate, small diameter tube for each cylinder
Cheers
DD
The older systems were plumbed differently with a separate, small diameter tube for each cylinder
Cheers
DD
#3
12-02-2011, 02:32 PM
If the air injection installation on your 4.0 XJS is the same as my 4.0 XJR....and I suspect it is...you're looking for a hose/pipe coming off the air pump and which eventually branches into two tubes going directly to the two exhaust manifolds.
The older systems were plumbed differently with a separate, small diameter tube for each cylinder
Cheers
DD
The older systems were plumbed differently with a separate, small diameter tube for each cylinder
Cheers
DD
So it gets coked up where it goes into the exhaust manifolds?
I have already replaced the Air Pump and the Valve.
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12-02-2011, 06:25 PM
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#5
01-31-2012, 12:02 PM
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Secondary Air Tube Rails
Wondering what's involved with cleaning the entire length of the tube(s). I too have been troubleshooting a P0411 on my 95XJS 4.0 and this I think would be the next logical step. I've already replaced the air pump and sprayed carb cleaner on the valve as I can't seem to take it off without bending the tube it's connected on. It seemed to help the code not to show up for a longer time span than usual but then again, it did come back after a while. I figured, if I take the tube out and replace the valve at the same time, I may fix it once and for all.
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02-26-2012, 09:01 PM
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02-26-2012, 09:09 PM
#9
02-29-2012, 08:49 AM
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P0411 solved?
Thanks - I have access to those through AllData DIY. Good stuff.
I checked the Air Injection Pump - It was not operating on start-up as designed. I checked the relay and then the 25 amp fuse on the block mounted on the left fender - it was blown. I put in a new fuse and it blew again. Went ahead and removed the pump and disassembled, the pump impeller was seized. I will pick up the rebuilt ($92) unit at the parts store and install tonight and advise. Hope this gets rid of the P0420 also.
I checked the Air Injection Pump - It was not operating on start-up as designed. I checked the relay and then the 25 amp fuse on the block mounted on the left fender - it was blown. I put in a new fuse and it blew again. Went ahead and removed the pump and disassembled, the pump impeller was seized. I will pick up the rebuilt ($92) unit at the parts store and install tonight and advise. Hope this gets rid of the P0420 also.
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02-29-2012, 09:00 AM
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P0420 and 430 ....both my arch nemesis....are cat converter efficiency codes. I wouldn't count on air pump replacement fixing them.
I replaced the dead AIR pump on my XJR for the 411 code....no change in the P0420/430 situation.
However, I *might* have fixed the problem with a new check valve in the pipe (old one had a slight leak) and tightening the pipe fittings at the exhaust manifolds.....which I apparently didn't run all the way home after replacing the exhaust manifolds. I haven't had a 420 or 430 code in quite some time now.
Fingers crossed
Cheers
DD
I replaced the dead AIR pump on my XJR for the 411 code....no change in the P0420/430 situation.
However, I *might* have fixed the problem with a new check valve in the pipe (old one had a slight leak) and tightening the pipe fittings at the exhaust manifolds.....which I apparently didn't run all the way home after replacing the exhaust manifolds. I haven't had a 420 or 430 code in quite some time now.
Fingers crossed
Cheers
DD
#11
03-02-2012, 01:02 PM
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Codes gone for now
I installed the pump and drove the car/went through a couple of start/shutdown cycles, but did not get out on the highway.
It was interesting that I had the battery disconnected during the work, when I re-started the the car the P0420 code was gone, but the P0411 was not. After clearing w/the scanner codes CEL went off.
Anyway, the CEL is currently off - no stored or pending codes.
It was interesting that I had the battery disconnected during the work, when I re-started the the car the P0420 code was gone, but the P0411 was not. After clearing w/the scanner codes CEL went off.
Anyway, the CEL is currently off - no stored or pending codes.
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