I have a 1996 XJS with about 70k on the clock. Of course it's got the AJ16 engine.

We've had some high heat here in the DC area.

Two days ago, when driving home on the highway, I noted the engine was not at full strength. The gas pedal was anemic and the automtic transmission was shifting badly, as if it was expecting the car to get to speed so it shifted accordingly. Hard and early shifts. Eventually went away on it's own.

The next day, while driving with the A/C on full blast, the engine stalled out after I turned the engine over. The anemic gas and sputtering came back in full force. I ended up stalling out a few more times! Poor shifting occurred again. At one point I needed the pedal all the way down to keep the engine from stalling out again.

Now in the past, I have heard the whoosh sound come from my gas tank when stopping for some gas. I happened to be low on gas at the time. In an effort to resolve my problem, I did step out of the car, open the gas cap and shut and the issue seems to have been resolved for now. Since I was out on a busy road, I could not detect the whoosh sound this particular time. I was listening for it, but I'm not sure if it wasn't there, or if I couldn't hear it.

Does anyone have similar issues with their facelifts? I've gone through the posts and I've read only a few issues with the newed 6 cylinder cars. I didn't think the car had enough in common with the earlier V12s to pay close attention to those posts.

I read a lot about the charcoal canister/Rochester valve going bad?
I was worrying that my fuel pump might be dying.
I also considered that the alternator might be at fault?

I am grateful in advance for any feedback. Thanks.

 

Hey Vee,

Mine did that 2 times; when the ECU had water ingress and when I had a bad ground (mechanic called it a stuttering ground)

You should probably also check your fuel relays in the trunk. There are 2 or 3 fuel related relays if I am not mistaken

 

thanks for the response. My ECU connector is packed tight with electric grease, so I'm going to rule that one out...for now.

The grounding issue would be worth looking into if my problem was more consistent. Nevertheless, it will go on to my project list when the family is out of town.

I'm going to attack the Rochester Valve first and I may end up replacing the fuel pump just in case. It's nearing its 20th birthday, right?

Two questions:
1. Is there a preferred brand? It was easy to select the OEM when I replaced the pump on the Ford Taurus, with the Jag, not so much. I believe my options are Denso, AC Delco, Airtex and Walbro.

2. Is there anything else I should do while I'm in there?

Thanks!