My 95 XJ6 will start and idle perfectly when cold in the morning, BUT the car will suddenly cut off as if I turned the switch off. It might idle for a few minutes before it will shut off. Again, it does it only when warming up. It restarts instantly and continues to idle perfectly for days until it does the same cutting off. Any ideas what is going on? My mechanic is clueless! THANKS!

Richard
95 XJ6 VP
97 XJ6 VP

 

The crankshaft position sensor can partially fail before completely fail . One of the partial uses of the CKPS in the enabling the fuel pump relay to stay closed in the second phase of the fuel pump control during the engine starting sequence . When you turn the key to on before the start position the fuel pump relay will click on for 3 - 5 seconds then click back off . This primes the fuel rail but will run out of this prime after a coupl of seconds of engine light off . Once the CKPS senses engine rotation the fuel pump clicks a 3rd time for the duration of the drive .

One way to bypass the fuel pump relay control is to put power directly to the fwd most point of the relay socket .

If you get positive results with this trick we can go deeper in this area . And if not look into the CKPS as it controls the engine itself regulation . And swapping the RH engine fuse box king relay ( Intermittent ? ) with the LH , ECU " first power " source and the ECU controlled relay as this gives the ECU it's " second power " .