ok people, need some brains . son has a 91 vdp. 82000 miles.quit on x-way had wrecker bring home. started up on wrecker backed off. went for another month did it again. same thing. went for about two months, quit again, this time it stayed dead. have 12 v at both sides of coil.good fuel pressure. replaced crank sensor. ign module.tried another comp.and checked all fuses still nothing. seems that something is keeping the ign amp from making and breaking the 12 v on the neg side of coil. power relay has voltage. need son out of my 2000 xj8

 

When the car stalls, what does it do. Does it crank? Do all the dash lights come on, etc?

Please dig through archives to find responses to other such posts. It seems like stalling and occasional non-starting is endemic to this vehicle! For example, and not to sound like a clanging gong, but... When a very similar thing happened on my '91 it ended up being a failing fuel pump relay - which would make sense given your symptoms and what you've already replaced.

Scott

 

like i said all lights come on, turns over,good fuel pressure.everything perfect. except the ign amp dosen't seem to make and brake the power on the neg of the coil

 

I'm assuming a lot here (like a proper fuel pressure test holding 40 psi at start up and throughout; clean battery leads; good grounds; properly seated distributor cap; a known-good rotor......), but if you've already isolated the ignition amplifier, why not just replace it and have done with it?

Scott

 

scott have replaced crank sensor, ign amp first thing

 

Jon,

I had an identical problem on a (non Jaguar) European and I nearyl scrapped a perfectly good car after having spent thousands trying to solve the problem so reply in this context....
Does your XJ40 have an immobilisor fitted either as part of a security (alarm) system or as an anti theft device on it's own.
If so they usually have an after market relay hidden somewhere in the dash and taped in black to make it look even more inconspicuous that fails and exhibits these very symptoms...as it is designed to do.. act as an immobilisor...
Good luck with it all...

 

not that i know of . had the car since 94. nothing added from factory