X300 XJ6 1995; Cranks but no start

A club member is having this issue. He also had problems with locking, remote, boot opener etc. which turned out to be a blown Security System fuse (F4) in the boot.

The car was working up until he wanted to investigate a slight misfiring upon regular driving. (He did find a crack in the frontmost coil/sparkplug cap which he ‘remedied’ with a shrink-tube.

After putting everything back together, the car would not start. It cranks but will not fire. All fuses checked (even a selection in the rear compartment has been checked.)

Any wisdom on this? I know I have been faced with this before but cannot remember what the culprit was.

Kind regards,
Bard Thomas

The simplest thing to try is the old “she’s flooded, floor the throttle” fix:

  • ensure that the battery is fully charged and in good condition. This exercise pushes it somewhat.
  • hit the throttle so that it’s right to the floor
  • crank her
  • keep cranking - have faith! My now-sold XJ40 once took almost a minute of cranking
  • be super-alert for when she fires because you’ll want to release the throttle then!
  • make a mental note to NEVER run these engines for less than 3 minutes

Use WOT favour 20 seconds then about 20% throttle as the X300 cuts off the fuel at WOT to clear flooding IIRC.
Worked for me!

Not sure where you are based and if the car has an immobiliser, but does the check engine light come on an turn off after a while when the igintion is switched on (withough cranking)?

Thank you for your insight, guys but, You’ll never believe what the reason was!

The fuel pump relay socket had been pushed through its holding pegs in the frame which caused an intermediate, and ultimately broken connection.

After a bit of tinkering getting it properly in place, the problem went away.

All the best,