I have 2 Jaguars. 1991 & 1992 xj6 w/4.0 automatics. The 91 is a daily driver to work. Any way the 91 didn't start one day, but did for 3 seconds. Went to restart and got nothing. No spark at coil, plugs, and nothing at injectors. After reading changed out the crank position sensor (taking it from the 92 Jaguar). Well it started, "ya". Drove it 4 blocks, then the dash gauges went crazy, door locks went down, dome lights came on, windshield "wiper
intermiten" came on. The car wanted to die, but reving it kept it going. In a*****it did this 4 times and then recovering. Does it more at idling and lower RPMs. Rebooted the ECU by removing Neg., turning the switch on then touching Neg. to the Positive for 30minutes. With no results. Now don't trust taking it from the house. Have changed out/traded from the 92 since it has never had an electrical problem. But problem still existed after trading out. Coil, Coil Amplifier,ECU, Micro processor, relay for the CPU, P.I. circuit, & instrument Pack Memory. I have changed these items out singly and have put the old 91crank position module back into the 92 and the 92 has started with no problems. I have checked battery neg. at the firewall & starter
, Pos. at the firewall insulater. It seems it takes a little longer before the gauges go wild now, but think now changing the crank position sensor could have been a coincidence. Was thinking it could be ignition in the running position because of the flickering of the gauges. But that wouldn"t answer the 1st problem of not starting, "car would have started in the start position, then acted up in the running position". Live in Oregon, no rust on ECU or Micro Prosesor.