Car dies after short drive

After 8 or 10 miles after start up jag dies. Will restart after 1 or 2 minutes, then dies after a few more miles. This continues until I get home. Any suggestions? I’ve owned the car since new so I know what’s been done on it over the past 30 years. Prior to this problem the engine ran rich, loped when idling and had a miss at idle. Never felt the miss while accelerating and driving.

Dave T VA Beach
1990 XJS V12 Convertible Marelli ignition

David,
I have one suggestion. Include the year, model, engine, and ignition type in your post.

Paul

Sorry, It’s been years since I’ve been on this post. I will repost my question with more detail.
Thanks for the help

1990 xjs v12 Marelli ignition

David,
We have a 1990 XJ-S convertible (5.3L V12 with Marelli ignition) so I know your car well. I suspect that you have a fuel delivery problem with debris in your fuel tank temporarily blocking fuel and causing the engine to die. If this happened to me I would connect a fuel pressure gauge to the fuel rail and observe the fuel pressure as the engine started, ran, and died. Fuel pressure while the engine is running should be about 36 PSI.
I had a similar problem in one of my Series III XJ6s and it was due to a lot of debris at the bottom of the fuel tanks that clogged the fuel strainers and fuel filter. I confirmed it by monitoring the fuel pressure.

Paul