After taking some time off working on the XK8 for the holidays and reading/ researching the LEAN codes on both banks. I decided to tackle the issue yesterday.
So far what I had done prior to taking the time off, was >
1. Remove and inspect the air intake snorkel. Result: good condition.
2. Found and repaired a split on the full load breather pipe from the right hand valve cover to the snorkel. Result: No leak there.
3. Removed and cleaned the MAFS, checked O-ring seal and replaced. Result: lean codes still coming back. I also purchased a Denso MAFS in case I need it. (Very expensive)
4. Did a smoke test and found no apparent leaks. Problem with my smoke machine is it does not have a feature to increase the pressure or the amount of smoke it generates, so I considered the smoke test a DUD.
5. Did a vacuum test and had a reading of 18+ hg/in.
6. Fuel pressure test. Result: 43-45 psi.
Since I had rebuilt this engine, all gaskets and o-rings were replaced, so something was amiss.
YESTERDAY:
After reading almost all of the posts re: P0171/P0174, I decided to systematically go through the whole system again and do some additional checks.
I removed the snorkel and noticed that the rubber inserts at the air cleaner end and the TB were not as flexible as they should be and could possibly introduce additional air to the system. I looked at the parts I had saved from the engine I removed and I had the rubber insert for the TB which was more flexible than the one on the car. For the air cleaner end, I wrapped one layer of self vulcanizing tape and applied some heat to it. I then installed the rubber insert over the tape and now the snorkel was a very tight fit.
I then noticed that the dipstick had some play when inserted into the tube. The o-ring there was hard, so I replaced it with a new one from an o-ring kit I purchased from Harbor Freight. Perfect fit. No more play there.
A few of the posts I read talked about the lower fuel injector seal being a point of concern. When I rebuilt the engine, I took the 8 best injectors I had (from 16) and installed them on the fuel rail, which I then installed on the engine.
I started the car and decided to spray some brake cleaner at the injectors. Started on Bank B. cyls 1,2 and 3 was normal. Cyl B4 when sprayed caused the engine to stutter. I found a potential leak.
Moving to Bank A , I did the same thing and The engine stuttered when I sprayed Cyl A4. Another potential leak.
I immediately ordered an injector O ring kit and as soon as it gets here I will replace all the o-rings on all 8 injectors.
I guess persistence pays off.
I will post the results after I replace the injector o-rings. Stay tuned.
I am very grateful to all who posted about the Lean codes on both banks without whose inputs I would never have gotten so far. Thanks guys.

 

Sure hope the new O-rings fix it. Good luck and keep us posted....

 

Rather than checking engine revs use STFTs as they are far more sensitive. You can easily fail to find a leak via engine revs.

 

Today I replaced all 8 sets of injector seals and took the car for a 150 mile round trip, driving in different conditions. Drove a bit at highway speed pull over, shut the car down, waited a bit, started the car and continued at highway speed. Prior to the latest repair the cel would light up and RP would show up on the dash. Presently, none of that is happening and the car drives beautifully. I drove like a gentleman and like a maniac throughout the drive and I am pleased to announce that at this time all seems well. Will continue to drive the car on a daily basis and monitor what's going on and will report back. Keeping my fingers crossed.
Thanks all.

 

The other thing is to park with a fully warm engine, look at LTFTs and if more than about 5 to rev to about 2500 and see if they drop near 0. If they do, hunt for the air leak but otherwise it's not an air leak.

 

I will. My scanner stopped communicating with my car, so I am looking to purchase a better one. Any suggestions?

 

i like the corded ones just because i am old and always used corded ones with no glitches. I have the icarsoft i930 and love it. Fully jaguar specific. Updateable and small. I know there are newer versions in the icarsoft line but i have no need to change. Dont know much about the wireless stuff but there are many members with the elm. Mostly depends on how much you need for the scanner to do i guess. I also have an older snap on modis with euro cars that has many features the scan only stuff cannot do including bidirectional controls. I got it complete for 400 bucks years ago. By now i would figure they would be cheaper

 

@scottjh9: Being old myself I am looking for the easiest way to do stuff now. I am just looking for a Jaguar XK8 specific scanner to be able to see as much live data as I can. I am nor intrested in reprogramming modules and such. I have torque pro with ELM 327 but it does not communicate properly with the car as many others have already posted.
Seems like the icarsoft i930 or a later version is what I need. Are you able to view live data on the i930?
Thanks.

 

I have the next icarsoft version, the icarsoft LR v1 . There’s a v2 but it cost more and is geared toward newer cars than ours, no extra features that apply to the X-100 series of cars.

My icarsoft LR v1 as the name implies is Land Rover / Jaguar specific. It can read codes and data in real time for most of the functions. Although it takes some getting used to, and is a little difficult to learn its interface, I still think it a good fit for our cars.

Z

 

yes the i930 can read live data. Either in obd2 mode or jag specific mode reading all modules. Here it is new on ebay. https://ebay.us/m/KAwFAd

 

I have put almost 800 miles on the car since my last post and so far no problems, no codes.
Now I have two other items to resolve.
1. ABS light on. Scanner says the problem is with the left front wheel sensor/ harness.
2. Battery charging but battery light on and "BATTERY NOT CHARGING" on dashboard. Scanner shows voltage at 14+ volts.
I have to go back and look at the wiring to the 3 gauge cluster. I installed an updated stereo system (Joying) and moved the 3 gauge cluster down to where the OEM radio lived.
In order to do that I had to extend the OEM harness to reach thebottom of the console. I did this by purchasing a used harness for the 3 gauge cluster to create the extension. I have to go back and see if I screwed up somewhere.

This is where I installed the 3 gauge cluster with the screen for the Joying stereo mounted where the 3 gauge cluster used to be.

 

Did you cut either one of these wires? That would explain your false charging warning.

 

Since I cut all the wires going to the 3 gauge cluster to add the entension, I will go back and check to see if any of the connections I made were not done properly. You never know.
The extra 3 gauge harness I purchased had a couple of wires that were a different color but I used the plug numbering to patch each wire to its corresponding pin on the connector. This patch is what i will be going back in to check. The voltage gauge needle is midway and using my scanner the voltage reading with the car running is 14+ volts indicating that the alternator output is spot on. It is just the red light that stays on and of course the reading in the meaasge center. The possibility exists that the gauge is faulty, (I purchased the 3 gauge cluster used on Ebay) because while trimming the white plastic case at the back of the cluster, I damaged the original one that was on the car.

 

While you are in there, check that FC26-22 pin on the harness as highlighted by RoverJoe and make sure the voltage it is getting from the generator is as expected - maybe you have a fault on your instrument cluster and checking what it's input voltage is would rule this in or out.

 

Yes the cluster is basically just looking for enough signal on that wire to know that the car is charging. You can test that and verify that the signal is getting to the cluster or not, as mentioned you could have a cluster failing, but since you recently did some wiring work i'd be more inclined to believe the trouble is on that side of the system.

 

Yesterday I replaced the alternator with another one I had from the original engine I removed from the car just in case there was an internal problem with the alternator I had installed with the rebuilt engine Result is the same. Alternator output =14+ volts, battery light still on. Today I will access the 3 gauge harness to check the wiring connections I made to extend the harness. While there I will check the circuit highlited by RoverJoe. What voltage should I be seeing on FC26-22? Battery voltage or Alternator output voltage. The reason I am asking is because I only worked on the harness going to the 3 gauge cluster

 

I would expect battery voltage and alternator voltage to be the same. The electrical guide says FC21-22 <3V for the warning light to come on, B+ for it to be off. So you should see 12v or higher in normal operation.

ETA - the wiring diagram and notations are mixed up in my electrical guide. FC21-22 should be the connection that goes to the alternator, FC21-1 goes to the minor instruments.

 

I honestly think I made a BOO BOO. The 3 gauge harness I purchased came out of a 97-99 XK8. The problem is that the wiring colors are different to the 2001 harness. I am also sceptical that the pinout at the 3gauge connector may also be different.
The 97-99 Electrical schematic shows RED/PINK(FC79-11) as the wire I have to deal with but it's located at Pin #1. I do not know which pin # the red wire(FC79-11) is connected to on the 2001 XK8
Does anyone have a pinout of the 2001 3 gauge connector or a clear picture. The connector has 13 wires in both the 97-99 XK8 and the 2001 XK8. My qoriginal connector was misplaced or thrown out when my grandson came by to help me clean up my garage, so I have nothing to compare the connections with.

97-99 3 gauge connector

97-99 schematic

2001 3 gauge schematic courtesy forum member

This numbering may be totally incorrect

 

Here's the pinout for FC79 from IDS. View is female front:



Pins 1 - 7 are unused,
Pin 11 would be the wire Red on 2001, Red/Pink on 1999.

Hopefully you can work out from here, but shout if you need anything further. Jaguar seems to do this wire colour juggling every now and again to keep us on our toes.

If you're getting a charging error in the message centre on the main cluster, then I'd be suspicious of the alternator regulator (or its input to the cluster).

 

The schematic I posted was for a 2001, it should have everything you need
I attached the segment of the manual as a PDF if you want to blow it up/print it out.