2004 X-type, 2.5L Manual trans, AWD

so I had vacuum leak problems, they're all solved (replacement brake booster hose was bad)

Now, we're trying to chase down a misfire on Cyl 5, the center cylinder on the front bank.

We had to replace all the back bank coils (don't buy the cheap ones, get the Jaguar ones from the dealership parts department!).

Now, cyl 5 misfires. We swapped coils around, the problem stays with the cylinder. All wires have continuity- the mechanic checked this when they cleaned out my ECU. Swapping in a different ECU did not effect the misfire.

the cylinder has good compression, so that's not the problem.


A shop down the road has the *exact* same problem with another X-type, Cyl 5 misfiring.


Has anyone had this problem before?

 

Could be an injector issue or a bad injector O ring?
Im assuming new plugs are in there?

 

Tumbleweed, Cylinder #5 is not the front center cylinder. That would be #4. Cylinder #5 is the back side of the engine on the far right side. This may help explain why changing parts is not fixing the issue. I can send you a diagram from a Jaguar reference that will give you the cylinder numbering and a lot of other good information relating to wiring and whatnot. Send me a PM if you are interested.

Because you have a 2004, I will also need the month/year that the car was made (written in the driver's door jam) to make sure you get the correct wiring diagram. Changes were made in early 2004 to the wiring system.

 

The attachment below shows both the previous and ISO cylinder designation for the AJ-V6 engine.

Bear in mind that the X-Type has a transversely mounted engine, so the reference to the 'front of vehicle' would in fact be the RH side. Cylinder 5 is in Bank1, which is the side facing the engine compartment bulkhead.

 

Finally! The problem is (knocks on Formica) solved!

Replacing individual parts didn't get it taken care of, what finally worked was replacing the ECU and the wiring on the injector rail.

There was too much resistance on the wire for injector number 5, which would cause it to not spray fuel every once in a while.


So, $1600 later, not to mention the $700 I spent on the rent a wreck, It's running like a champ again, and I'm off to get a bluetooth car stereo (I got very used to that!)