I have a 1996 xjs that I just bought and it has 165000 miles on it. The previous owner said it had been sitting and rarely driven for the past year. It is in good condition except around 2500-3000 rpms it begins to stumble almost as if it has a rev limiter. It will bounce off a maximum of 3000 rpms and won't go any further than that. I just replaced the spark plugs hoping that would help. It runs a little smoother but still has the higher rpm issues. Today it stalled and the transmission fail light came on along with the check engine light when I tried pushing it past 3000 rpms. The trans light went off when I restarted the car but the check engine light is still on. I'm new to jaguars but I'm hoping to do most of the work as I do with my bmws. Any help would be great

Thanks

 

Assuming it's the AJ16 4.0L six cylinder with coil-on-plug ignition, I'd take a hard look at the coils. They are sorta known to give trouble.

Although a year storage isn't all that long, I'd wonder about old gas as well.

Cheers
DD

 

It has a fulll tank with the techron fuel system cleaner. And the coils look good as well. I'm really confused about this one.

 

Get an OBD II code reader and see if it comes up with any trouble codes.

Cheers
DD

 

Hey Doug...how far back will the OBD II reader work?

Thanks...and sorry for temp hijack!

 

I had the codes read and I'm getting P0727 and P1775. Which are engine speed sensor circuit no signal and a transmission fault. I'm not sure if a bad crankshaft position sensor would cause this? Also today for some reason all of a sudden the exhaust got very loud and has continued to be loud. It almost sounds lawnmower loud. I'm not sure if maybe I cracked the exhaust manifold or if it is somehow related to the codes. I put her up on the lift and checked all the visible places on the exhaust system and found no holes or broken welds.