Hi all,

Just picked up a 98 XJR for future son in law. Engine starts idles VERY rough.

Here is the WEIRD thing. Bank 2, after idling for a minute or so is WARM/hot.
Bank 1- COLD.

Tensioners are metal 3rd gen and intact.

I am GUESSING electrical, but I have not experienced this before so I wanted to see where we should look next.

Thanks in advance!

D

 

Pull the plugs and check them, ....do you have any codes? Trace the wiring for the coil packs and see if there is a broken or disconnected wire. How is your fuel delivery on that side? Your plugs should be wet if they aren't firing.

 

I would test for spark using the old "lay the coil on the engine with a spare plug" method. If spark is ok, then look for something slipped in the timing.

 

If you have an OBD2 reader check the codes.

You may have to replace one ignition coil.
The code will tell you which one.
I've done this a few times & have a thread here somewhere on that with diagrams so you can tell which coil is #1,2,etc.

 

1998 was the only year with a AJ26 and not a AJ27.

The ignition on the AJ26 uses two modules. One for
each bank. One bank being dead would point at the
module, no power or no ground.

 

The ignition coil drivers are mounted on the firewall next to each other. You can swap the connections to verify that one has failed.

 

Ok, switched ignitor and swapped some coil packs- I *should* have done this first: compression test...cylinder 4 zero. I guess that ticking is a valve kissing the piston...hopefully not too much damage, disassembly starts this week!