So, I've had two incidents of "Restricted Performance" since Friday.

Incident 1) It was raining out and the car had less than a quarter tank (60 miles DTE). A typical Ohio jackass cut in front of me forcing me to slam on the brakes and swerve lanes...Then when hitting the gas, close to WOT, the amber MIL light illuminated and "Restricted Performance" was displayed. The car felt like it was "dying" but kept going slow...the light went out and it accelerated smoothly again..

Incident 2) This time it was dry and clear and I have a full tank. I goosed it on a long entrance ramp getting on the highway...POP...Amber MIL, "Restricted Performance". This time, since it did it once before, I tried feathering the throttle and the motor started stuttering real bad..Like it feels when you are starting to run out of gas....

I have noticed over the past couple of months that it has felt sluggish. Enough that I was considering going and doing a "intake off" tune up.. Basically change plugs and go through things.

So, I pulled the codes and here is what I got..

P0300 - Random Misfire
P0302 - Cyl 2 Misfire
P0304 - Cyl 4 Misfire
P0306 - Cyl 6 Misfire
P1314 - Misfire rate Catalyst Damage Bank 2

So, what has me curious is typically these codes point to a fuel delivery issue (like a fuel filter, clogged injectors, etc) but why are they all on one bank? Why does it only happen occasionally during WOT? Not every time. I've "floored it" a couple of times in between incidents and nothing..

The MIL has not stayed lit either, it only lites during "restricted performance".

 

One or more COP (coil over plug) failure?

 

You're still under warranty, correct? So run this by your service manager. I'm betting that he will recommend two initial actions:

1. Replace your IMT O-rings if you have not already done so.

2. Perform a complete fuel injection AND induction cleaning.

 

Interesting idea... Could it be triggered by the high firing rate / load required by WOT? Funny thing is nothing really going on during normal drive. No rough idle or perceived misfires.

 

1) Done a while ago...

2) Why would it be only recorded on one bank? Cyl 2,4,6 Bank 2...

Yes, under warranty...

 

Misfires in only one bank is not unusual. I remember several misfire issues reported on this forum over the past year or so that affected only the odd-numbered cylinders.

When our car had misfire issues last October, they occured only in cylinder 3. Which happens to be the cylinder closest to the location of the IMT O-rings.

The research I did prior to and shortly after purchasing our S-Type taught me that the orafices in these fuel injectors are almost microscopic and tend to clog, thus causing misfires. Multiple Jag techs on several different forums have recommended fuel injection and induction cleaning at intervals as short as 25,000 to 30,000 miles as routine maintenance necessary to keep misfires from occuring and eventually damaging the cats.

You should also check to ensure that your air filter housing box is sealed tight with no broken or cracked corners. That issue is also known to trigger misfires.

 

Good ideas above. As it's under warranty, that's probably the easiest route.

If my car did it (no warranty) I'd be looking at fuel trims and comparing the two banks. (After making sure it was running closed loop on both banks.) Also, I'd compare the O2 sensor waveforms bank-to-bank. Just in case any oddities to suggest where to go next.

With so many misfires and all on one bank I don't see it being COPs as they don't all fail at once. And probably not injectors as why 3 out of 6 and all on one bank? So, what is there that's common to all cylinders on one bank? Maybe an O2 sensor or an air leak on one bank (could be exhaust leak, doesn't have to be induction, though intake side is commoner I think).

What else is different about the 2 banks that might explain it (without needing 3+ things to fail and all on the same bank)? Harness?

It could be failing, but not so obviously, at more than just WOT, in which case OBD may assist.

 

So, I talked to Mike today. He said it could be many things triggering the misfire "under load". He said some of the common things would be COP failure, throttle body issues, and in some cases a vacuum leak. He said that the codes I'm getting is what is making it real strange (figures). The above mentioned symptoms would normally be present in a single cyl or random cyl's across both banks. The fact that it is only triggering codes on one side and only occurs randomly under WOT is making him want to run it on the IDS system. I even floored it while I was talking to him (hands free, of coarse) and it didn't act up. The random nature of the problem along with it showing codes on only one side of the motor is making me scratch my head..

Since it is going in this coming Monday for a buff and polish, he wants to send it over to a tech and run the diagnostics. I said great since we both know the IDS system is going to give them more data than my code scanner ever will.

 

are you able to view the freeze frame data?

 

Yes, My "crappy" scan tool will let you do it. It also reads Jaguar specific codes as well. It just doesn't seem to go past the PCM on Jags, but will on other cars.

I got it to do it twice today..It still only happens during WOT. Funny thing is it also seems to do it close to where the rev limiter is..I say funny because it may not be up shifting on time since it does it in third or fourth gear.

It goes like this... Floor it..It starts to Tach up to redline and either shifts or pops into restricted performance..It is weird..So, I wonder if it is the TCM that is acting up. If the PCM rev limiter is intervening, that may explain why the misfire codes show up all on bank 2. Then again, would the PCM command then trigger a trouble code???

At least I can now "make it happen" and show a tech what it does.

 

can you capture the freeze frame and post it?

 

The TCM isn't going to try (or be able, realistically) to flag misfire codes all on one bank!!

Had a look at the stuff I suggested yet?

 

I wasn't thinking that the TCM was doing it... Just thinking that if the TCM isn't triggering an upshift when required under WOT it may be allowing the engine to hit the rev limiter.. And the limiter program may be to shut off one bank... But then my next question becomes, why would there be DTC's if it is simply hitting the rev limiter?

Yes, I know I'm second guessing a lot, and shooting holes in my own theories.

No, I haven't hooked the scanner up to look at the trims and such since Jaguar Cleveland has offered to hook it up to the IDS system.

Today's incidents were self induced. I wanted to see if I could get it to do it if asked. This way I can take Mike or a tech out for a test drive and get it to pop into "restricted performance" on demand. If everything comes back inconclusive, then I will run the scanner and produce the fault myself and capture data.

 

It's not the TCM in any way. It just isn't. You look to have classic misfires, whether air leak, bad harness, O2 sensor or whatever is causing them.

 

Soon to completely die coils?

 

3 out of 6, and all on the same side? Sounds very unlikely.

 

Jagv8, that makes sense. I withdraw my diagnosis....Josworth, change the whole friggin engine!

 

It's under warranty - change the whole car

 

If you really want to eliminate coils, swap one bank with the other. My guess is it will jump to the other bank, and its either one coil affecting the other two on the same bank during the RP conditions...or the 02 sensors on the exhaust.

check fuel trims, definitely, see what the 02 sensors are sending back.

 

That just may happen. LOL

I think my car is just pissed at me... It is fed up with me treating it like a STR, day in and day out. So now, every time it revs up to red line it just decides to shut off.. Brings a whole new meaning to the term "restricted performance". In my car it means... "you can't drive me like that anymore you moron!".

Actually, if my memory serves me right, I may have the opportunity to become a tuner! Many people complain of their STR short shifting. Somehow I've trained that confounded ZF box to hold gears right to red line.. Sooo, all you STR guys, send me your TCM, I'll install it in my car and drive it for a month then send it back "well trained". LOL

Seriously, I'm going to hold off any more real diagnosis until the dealer has a chance to go over it. If it comes back with "no faults" then I'll start the methodical process of diagnosing it myself.. And yes, JagV8, I'll start with capturing data...Please be ready to help me interpret it, since that is one area where my skills are lacking....