Hi Folks, my questions regard a '98 XJ8 that I suspect has a jumped timing chain.

I am attempting to set TDC.
Cylinder 1a is at the right(passenger side in USA)front, correct? When setting that cylinder to TDC the alignment hole in the flywheel is not visible through the hole next to the engine speed sensor. With cylinder 1b(left side front) at TDC the hole is visible and approximately centered in the odd shaped opening.
I believe cylinder 1b,left front, is the one to reference, yes?
I do not have the factory tool to align the flywheel and given the odd shape of the hole I have no idea how to devise one, any ideas, better yet pictures of a homemade device? Aftermarket source for one?
With 1b at TDC(within a couple dgrees for sure)all cams are advanced past the point where the flats align. At a few degrees before TDC all four cam flats will align. No slack in secondary chains and no broken tensioners on top. I think the primary chain has skipped.

What say the learned here?
Many thanks

 

the timing is not set to TDC, it's 45 after TDC, that's why you're not seeing the timing locking hole (and cam flat alignment).

 

Thank you. Which cylinder is where to set this up?
I have looked and cannot find the procedure documented. I bought a pirated a Jag service CD that is worthless as the files can't be opened.
Care to help this Jag neophyte?

45* ATDC ? Is it just me or did Jag engineers spend too much time in the pub.

Wait #1a 45* ATDC correspods to 1b @TDC, no? this is where I'm seeing the alignment hole.
Do the Brits reference the cylinders differently?

 

You can download JTIS from here https://www.jaguarforums.com/forum/g...rchives-65926/
Cyl numbering is in the attachment.

 

Thanks Norri,
I've found and attempted the download, my computer is having none of it.
Any body care to be a sport and explain which cylinder is supposed to be where to check cam timing?

 

just lock the drive plate with a modded bolt, and check all cam flats are aligned with a straight edge, if not you'll be able to see what has slipped, usually the secondary chain, but if a lower tensioner has failed it's possible one of the primaries has.

 

I see the spot where the tool would go into the flexplate but the access hole is huge and irregular shaped, I can get several fingers in.
I can't even find an image of the factory tool, only sets in boxes and I can't tell anything.
Still trying to get the service manual to download

 

The hole that the tool goes in to lock the flexplate is found when you remove the crankshaft position sensor.

 

Now it is beginning to make sense. Thank you

 

I haven't looked at this in a while but I think it's all there Free Cloud Storage - MediaFire

 

Sorry to belabor the point fellas but I'm still unsure which cylinder is to be referrenced for cam timing.
With the front cylinder of the right bank(passenger side in USA) @ TDC the cam flats align and there is an oblong hole visible and aligned with the opening for the crank position sensor.
I am reasonably confident cam timing is then correct in spite of a real live Jag "tech" hearing and driving the car insisting the timing had jumped.
The hole in the flywheel I'm seeing is at ~8 o'clock in the attached picture.

 

What did the jagtech base his assessment on? there are 2 distinct things that happen when timing is out
1. The engine has a rough idle, numerous misfires logged on failed bank along with a rattle or clatter. One tooth out...
2. Seized or very noisey rough running engine usually terminal to pistons and cylinder head. Two teeth out...

Does your engine exhibit any of these symptoms?

Also don't worry about finding number 1 in relation to the timing, it has nothing to do with it, if you can get a factory tool in the CPS hole and lock both sides of the engine down at the cams, it's timed. The correct tools make it so easy to confirm and can be loaned off members here if asked for.

 

Thanks Sean,

I'm not looking to lock down the cams but just confirm that cam timing is correct. I cannot even find a picture of the business end of the flywheel locking tool to confirm my suspicion of the hole into which it fits. Is it indeed the one with rounded ends among the square holes?
Simply getting the tool into the hole is very useful for assembling but for checking the possibility of 180* off exists if I don't know which cylinder to reference.
The car is currently in the air with the flywheel hole descibed centered in the crank sensor mount hole, all four cams in alignment, and piston #1 at TDC.
I'm reasonably confident all is well but am hoping for confirmation given that a "pro" was quite smug while telling me in a condescending tone that it had slipped a tooth.
Symptoms are;
First a little history; This car, '98 xj8l 77k miles, was bought with a failed trans and also an intermittant non starting(fuel pump was cause). It had no doubt been jump started, or attempts, many times. I never drove the car and have no history.
After trans was repaired rebuilder called to say the trans was done but the car ran awful.
Fault codes all referred to fuel mixture, I cannot remember them and won't be operating the car again until I confirm that cam timing is correct.
"Restricted performance" intermittant, symptoms are constant.
Rough sputtering idle as soon as any temp in the engine. Cold starts fine and initial idle quality is good which leads me away from thinking a mechanical fault.
WAY down on power, barely able to accelerate UNTIL the revs can be coaxed up to 3k at which point it like a switch was turned and full power is available, again leading me away from a mechanical fault.(cocky jag tech didn't listen about this and refused to try and run it up past 3k stating he knew the problem)
At under 3k speeds it feels VERY rough with strong vibrations transmitted through the driveline when the torque converter locks up and will buck violently on attempts to accelerate.
Also various odd electrical anomolies, SRS light mysteriously on, traction control failure and ABS warnings that come and go. I'm topping off the battery to be sure low voltage which I supect is causing the gremlins is not the root of the driveability issue.
Fuel pressure is checked and correct
spark plugs previously were wet on the right side bank but now dry after last running.
Coils all believed good , ignition modules switched while right side had wet plugs with no change.
Air breathers in rocker covers clear, no vacuum leaks detected.
T-chains are tight and secondary tensioners are intact.
I guessed(not usually my style) at the electric throttle assemby being the culprit so exchanged it for a used one with no change.
This is where it stands. The car shows no signs of previous tampering and I tend to believe the seller's story that it ran fine until the trans failed. It is damn near impossible to drive at all as it is. The car appears to have been gently treated and is in otherwise very fine condition.

I fear an electronic issue as in ECM, perhaps the result of a voltage spike while jump starting.
Thoughts?

 

Do these help?

 

Sure do. Thank you sir!