Hello All,

Talking about my 2002 VDP, 80K miles. This car was garaged all its life so everything on it is in pretty nice condition and easy to disassemble/reassemble. I decided it was maintenance day and changed the fuel filter with a K&N PF-1000 and spark plugs with NGK Iridium BKR5EIX-11 in the same afternoon. Correct torque everywhere, etc. - nothing broke during the process or anything like that.
On the second drive afterward, I get a MIL and the code is P0336, Crank Sensor Range/Performance. I think, there's no way the sensor went bad at the very moment I did that other work, it's too coincidental. But I also have a new performance issue in tandem. The car is smooth and powerful in low gears like 1, 2, 3. When on an on-ramp or the highway, at speeds over 50 mph, if I need to accelerate I get a decent amount of misfiring and low power. Cruising at 70mph is flawless. Only acceleration at those speeds is problematic.
So then I think, "Well, maybe the crank sensor really did crap out for some reason and the car can't deal with acceleration at high speeds because of it." So I went ahead and replaced the sensor and of course it doesn't help at all.

Does anybody think either of those maintenance items could be tricking the computer into thinking it has a CPS reading problem? Fuel filter can't provide enough flow at those higher speeds? Something about the amount of power the plugs consume, or grounding?

If anyone has similar experience or any ideas, please let me know - thanks a million!

Garrison

 

It may simply be dirty? Pull it and clean it with electronic cleaner, also check the wires for damage/breakage since road debris can do such.

 

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Thatsnomoon, I don't have personal experience, but as you have replaced the CPSensor I guess we can rule that out. I did a P0336 search and found this info............ the link does suggest checking the battery condition as this can trigger a P0336 code, and another was to check for a weak starter motor?

https://www.autocodes.com/p0336_jaguar.html


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From the AJ27 DTC guide.

P0336
CKPS reluctor (on drive plate) foreign matter /damaged teeth

CKPS sense circuit: intermittent open circuit, short circuit to ground, short circuit to high
voltage

CKPS failure

 

Thank you everyone. Carnival Kid you're right that it's a new part now, so - I don't think debris or a dirty sensor. I had, in fact, taken the old one out and cleaned it up and tried it again before ordering a new one. I made sure there were no tiny metal filings stuck to the magnet when I put it in.
Also the battery is only 6 months old but I'll have it checked.

motorcarman - I guess I like the "Intermittent open circuit" part of the your list! I'm going to try adding a temporary extra ground to the engine. I can see grounding issues having come up when taking out the ignition coil packs on each of the spark plugs. Maybe there is debris on one of the packs that is preventing it from grounding well. Or maybe if the ground to the packs is supplied by the wiring harness, a wire in the harness itself cracked. I suppose a redo of the installation of coil packs is in order.
I'm not sold on the "damaged teeth or foreign material on the flywheel" bit, since again it just seems all too coincidental to have happened, while parked, during other service.

Thanks again!
Garrison

 

I think it's related to coil pack removal during spark plug replacement. Maybe a bent pin on the 4 pin connector on the coil? distorted spring in the boot?

 

Hi Gran Torino and everyone,
I'm still struggling with this problem. Because of your suggestions I took out each coil pack again and cleaned up grounding contact points and inspected each spring. I think those things are in as good condition as they can be. I have three questions at this point:
1) If a coil pack was misfiring due to a bent pin or such, wouldn't I get a different code that would tell me exactly which coil pack is failing? I know there are codes to indicate problems with the packs.
2) Since my old and new crank position sensors both throw the same code, what does the sensor connect to? Maybe that's what has gone bad. Is it one of those relay boxes or something generally replaceable?
3) If I perhaps damaged a wire in one of the coil pack harnesses (by slightly bending it?), are those harnesses able to be replaced? They look tightly integrated with the rest of the loom behind the block.

Thank you all so much for any other ideas or answers. This is really frustrating and the car's performance is still terrible when it goes into overdrive and gets any little extra juice beyond cruising throttle. It will hit overdrive before the end of a highway on-ramp, and sometimes the car will lose almost all power and start to decelerate until I let off the gas and gently try to bring it back to life.
Garrison

 

Thatsnomoon, I don't have any answers for you, but did run across these links, which you may or may not have already researched. Neither are Jag specific, but maybe there are some useful tips in them? One mentions crank-timing to cam-timing comparisons?

https://www.obd-codes.com/p0336

https://www.yourmechanic.com/article...-jamahl-walker

 

1. Yes - individual coil pack codes.
2. Engine harness connection to ECU.
3. Engine harness - it can be replaced, but easier to patch a new lead in with solder/shrink tube. It would post a coil code.

Fuel filter/fuel pump? Have you any other codes? Intermittent fuel pump failure can lead to pulling all your hair out, but it maybe worth checking fuel pressure.
Power strangled at higher speeds naturally lead to fuel & or air, suggested the fuel side, how about switching the filter. back and seeing if you get power back?

Also I think your plug gap isn't helping, it should 1.0 mm not 1.1 mm - i think!

 

Have you reviewed the teeth for the CPS as shown in Bob's post? Silly Q, but have you cleared the P0336? If not, it will not allow the car to perform.
Check this code definition out, https://www.autocodes.com/p0336_jaguar.html ...along with Bob's, it describes checking the Signal Plate for damaged. Perhaps Bob could elaborate on this for us? I'm pretty sure I know what it is (the teeth spacing), but I defer to the expert...
I'd also like to ask Bob if the Camshaft Sensor could be at fault?

 

Just spit balling here but did you verify the spark plug gaps before you installed them. Are they the same spec plugs as what came out? Might be a pain but you could put the old plugs back in as a way to eliminate the spark plugs as an issue.

Good luck. I've always found that diagnosing cars is MUCH harder than actually repairing them.

PS - I used to have a chart but can’t find it right now; I think the GAP was smaller on some of the later engines, yours being a 2002 and all... I’ll keep looking for that info to see if my memory is wrong. Check the gap on the plugs you took out.

I found the chart. It was published in 9/2003. I was apparently thinking about the 1998 model year (AJ26) which had a much larger gap. Anyway, here's the chart if anyone finds it helpful.

 

I would forget the codes and go back to basics - fuel filter first. Is it maybe installed the wrong way around? If correctly installed, I would try with another filter.

 

I have not checked the part numbers to see if the fuel filter is correct or if you installed the correct plugs. In my experience spark plugs have to be really a mess to cause major problems with modern engines and electrical systems. Obviously -- if you have the wrong plug .. that's one thing .. but, my guess is it's not the plugs if the part is correct. I also don't think the double iridium are to be gaped -- that's why they sell all the different varieties. Having the correct plug is very important -- I don't even like to install cross referenced plugs. Both of my R's are untouched -- so, I don't have the reference number for the plugs. It's been noted on the forum.

As to the fuel filter -- Jaguar often used a large Delco (GM) filter .. that's what I have always used for replacement, When I did my fuel pumps a couple years ago -- I replaced the original and they still used the Delco (I bought the car new and it was never touched until that point). They go for around $20.

So what's your problem ? I would go back and look at the wire running to the sensor and see if anything could have happened. These are old cars -- the wires are thin and strange stuff happens ... you may have to open up the loom to follow it. You worked around when doing the plugs -- maybe pulled on something. The open circuit makes this a likely possibility.

As to the misfire... I would be looking at fuel. Try getting the car on a smooth surface at 50mph -- or a slight up hill. Keep the power on -- but don't accelerate ... see if you feel any rumble. That was the first sign my pumps were going -- the VDP has only one. Since I don't like K&A -- I would be switching that out anyway. You could try that first. The pump is not "if" .. it's when.

 

Hi Sean,
I didn't know how you could tell what the gap was - but the part number NGK Iridium BKR5EIX-11, does the "11" stand for 1.1mm? I just ordered off of Amazon for my car and I bet they aren't reliable enough.
Sadly I don't have the original plugs anymore but I am going to start with a new set using a part number that is on the specs that Harvest14 added.

Now as for the fuel filter: Definitely not installed backwards. I had thought about power cuts = choking from lack of fuel but I think I ruled that out by putting it in Sport mode and flooring it, which would also presumably suck the maximum amount of fuel possible. The thing will fly. In fact, in Sport mode, I don't even get the ******* problem on an on-ramp. When RPMs stay high you wouldn't think anything's wrong. This only becomes apparent when asking for power at low overdrive RPMs.
And yeah - *when not *if your fuel pump goes! You're not kidding. Experienced that at the classic 120k miles on my wife's XJ8. What an immense pain. I was hoping to stave it off a little on this car by keeping a clean fuel filter which keeps the pump from working extra hard pushing against a clogged filter. You couldn't blow air through the one I took out of my wife's car.

Anybody still think fuel pump or filter could be to blame when it has the ability to deliver maximum power through all the lower gears?

Thanks all, your input is helpful and very encouraging.

 

+1 fuel filter: I would go with post #12. That was my first guess. You are having a fuel starvation problem. I would go buy that freaking huge AC Delco filter used on GMC trucks, install it instead of the the KN -- be sure to pay attention to arrow, it points to the engine.

Now if this was a Nissan Maxima: front bank camshaft sensor for sure: the rear cam covers leak oil down onto the sensor and shorts it out.

 

Fuel filter - okay, you got it. Going for that first. Thank you, I will post the result here this weekend.

 

My quick search comes up with your plugs being correct.

 

With the AC Delco fuel filter you recommended installed, all my power is back during all phases of acceleration. I still have a MIL for P0336, and it's been temporarily disappearing and then reappearing, like the computer can't figure out what it thinks with the new level of fuel pressure to work with. Sometimes it will cut all power to the engine for like 1 full second (feels like an eternity), and then the MIL will be off. Feels like the computer is rebooting or something. It will stay off until sometime during the following key-on. Driving along happy, sitting at a stop sign waiting to turn, and then it's back. No performance change that I can tell - the car seems to perform exactly as it should.
My best idea from here is to do a hard reset to see if the computer will re-learn and decide that it's happy. I'm still pretty darn sure this has nothing to do with my crank position sensor (which was also replaced as mentioned way up in the top of the thread). If anyone has any other ideas for me I'm still all ears. Per Carnival Kid's links, a slowly failing tachometer sensor has occurred to me as a possibility. But I have no data so every idea feels like a shot in the dark, which I hate.
Thanks All.

 

Have you cleared the OBDII historical codes? Sometimes they will keep a MIL until reset. I doubt a hard battery reset will help: usually has no effect on MIL.

Go back to position sensor and check that there are no bent prongs on the connectors; then track the wiring back as far as you can -- I suspect a broken or grounded wire.

Nice that it runs well, tho.

 

Hi Jim, thanks! I'll clear the code (because I thought it would clear itself due to the intermittent shutting off and reappearing). Regarding that trace - will do on the weekend and report back.