Hello to the Jaguar xj8 Forum,
Awhile back (Last year) I attempted to do the timing tensioner job on my 49000 mile xj8 L that was operating perfectly prior to my maintenance effort, After reassembly ,I tried to start up the car,It would not initially fire.During the third attempt cranking about 20 seconds it backfired and I immediately stopped
any further attempts to start the car. I then took the valve covers off and rotated the engine to check for cam alignment- it was off , I then rechecked my process for adjusting intake cam vvt and noted that I had incorrectly set it to full advance, I have removed the intake manifold and have made a plate seal each intake valve while doing a leakdown test. I do note a little leakage at some of the intake valves but nothing that changes the gauge value on the leakdown tester when I remove the plate seal, Do I need to remove the heads and do a complete valve job or could this small leakage be carbon buildup and I could just clean the valves.I have very high leakage values in the cylinders and I attribute that to flooding of the engine during the repeated startup attempt's and having the car sit for 9 months. Thoughts for next steps to do?

 

Reset the camshaft timing using the correct special tools. Refer to the information in this Engine Course:

https://www.dropbox.com/s/vqpy3bbjzd...e_168.pdf?dl=0

Pay particular attention to pages 22 through 26 of the course. The page numbers are at the bottom of each page of the document (pages 72 - 74 of the PDF).

Once the camshaft timing is correctly set, you can then proceed with checking compression, or performing a cylinder leak test.

 

Thank you for the reply,
I failed to list all I did before doing a leakdown test. I aligned the cams and reset the vvt using the correct tools and followed all the procedures listed in the engine course (I had previously downloaded and studied all available info)

 

Are you sure the camshaft timing is set with the crankshaft at 45 degrees ATDC? A common mistake many people make is setting the crankshaft at TDC whilst timing the camshafts.

 

Thanks again for the quick response,
I set the crank with the locking pin and aligned the cams with the kit that has all of the associated tools for the cam adjustment including the dual locking bars. My mistake was adjusting the vvt with a set a vice grips while I had locked the vvt with the chain off but turned the wrong direction.My tool for the vvt broke the pin and I could not use it.

 

Then you're going to need to remove the primary timing chain and reset the VVT unit in the correct direction.