Have been getting the P0307 and P1316 codes when the engine is running. I looked them up and see that there is a misfire condition in the #7 cylinder ("B" Bank #3). The engine runs good but there is a slight vibration detectible when I place my hand on the intake. The fuel injectors were just cleaned and flow matched prior to this and since I am the new owner to this XK8, and it was purchased as a non-runner, I do not know what the history was. In order to get it to run, I replaced the Starter, had the Injectors serviced as stated, changed a bad Crank Position Sensor and oiled the cylinders to bring the compression up. The plugs need to be changed since I used the plugs that were in the engine just to get this going, and they are nasty looking. Plug number and type is correct for the engine, and replacements ordered are the same. The concern I have is that the cylinder in question may have low compression - this is the first thing listed in the "Possible Causes" section of the DTC's. No other codes are set. Is there any way to bring the compression up, short of ring replacement? Has anyone encountered a similar situation and been able to correct it without major engine surgery? Again, it starts and runs very nicely for extended periods of time (except for the slight vibration noted above). Thanks in advance for any inputs on this...

 

swap the coils on 7, 8 and see if the problem stays or moves

 

If you do need coil packs the most cost effective source I found was CarQuest. I recently did all 8. Dealer was $175.00 for one, found on line for $148.00. Dealer matched that price and I bought the remaining 7. Check later with Car Quest not thinking they would be able to get them, but they could get the same Denso coil packs for $108.00 each.

However the reason I even considered coils was I got a screen message of restricted performance. Dealer did the diag for me.

 

I replaced the plugs with new NGK's and swapped the coils around and the codes still come up - P0307 and P1316 - The JTIS says possibilities could be related to Ignition Module, ECM, Broken Valve Spring, Low Compression. The engine runs very well at any speed but idle - at idle I can feel the miss (vibration) when I place my hand on the intake. I am truly baffled. There is no "Check Engine" light on and no Amber or Red light or message to indicate a problem. Just the codes - I have not driven it yet - maybe that will help...Any ideas???

 

This is a copy of the Cylinder ID for XKs.



Your description of Cyl #7 (B bank #3) seems to be different than shown in the diagram.

 

Thanks for the info Paul. The JTIS I am using shows the third cylinder from the front on the left hand side (driver's side) as #7 cylinder (B bank #3) that will set this P0307 code. Same cylinder as the #2 Bank #3 cylinder in your diagram. I have switched coils around on both banks and installed the proper new NGK plugs and still get the same codes. The old plugs looked really good and were firing properly. This is a baffling mystery...

 

now swap injectors

 

Can I ask someone (Paul?) what the implication of "2002.5 MY" means? Is there a specific vin # separation - and were there other changes? I have a 2002 XKR, and it would be good to know which side of the fence I may be on. Thanks. DaleD

 

Very good question. I was aware that there were changes made in February 2002 but was never sure that was the reason for the '02.5 designation.

A VIN number would be a great addition to the knowledge base.

 

Youre a 2003 model designation, 4.2 engine and other changes to vehicle build specs.....and no i dont know all the changes off the top of my head. But that it the typicle meaning of a .5 designation

 

I agree with Brutal, the next step is to look at the injectors. Not long ago, I had an XJ6 that idled rough in neutral but ran smooth when put into drive. It turned out that one injector failed to squirt fuel at minimum pulse widths but worked fine as it opened up, causing a misfire at no-load idle. As soon as anything increased the injector pulse (including turning on the AC or putting the car into gear) width more than the minimum 3ms, it worked fine!

 

What was your remedy i have exact codes and it reset itself, comes and goes periodically after i reset,and it reset it self by so many issue less starts thanks

 

I had P1316 and P0308 and the problem ultimately ended up being intermittent coils.


Dave