I have a 99 XK8 that will not start. I usually store it during the winter and did so again. When I reconnected the battery it started on the first turn. I drove it for the day and it started right away several times. When I returned after 30 minutes to start it again it would not start. It turned over fine so it is not the battery or starter. The gas tank was full with premium gas and additive so I believe the gas is good. The crazy thing is that it ran fine all day with good power. Could it be the plugs? Or the fuel filter? I noticed late last year that the check engine light was coming on intermittently. It was on when I started it this year.

 

Welcome to the forums edo799,

If the CEL was/is ON, you will have relevant stored or pending codes which will save a lot of guesswork and help systematic troubleshooting.

When you get a minute, please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

The Check Engine Light (CEL) could be a multiple of sins. Taking a car out of winter storage is always worrisome and sorry to hear about your current starting problem.

With the XK8, always start with the battery - get it tested, even if “it’s not old, it ran fine yesterday.” The XK8/XKR is really picky on a good battery. Cold Crankage Amperage is key to start up.

If that doesn’t help, then it’s time to go and get the OBD plugged in and come back here with the codes. Forum members love picking through these. You’ll get a tonne of help if you post a thread saying “ P0xxx - help.” Specifics are best to get a targeted response

 

Checking for fuel is pretty simple. Locate the schraeder valve on the fuel rail. It looks like a tire inflating valve. and usually has a dust cap over it. Once you locate it turn the ignition to the on position and wait for the system check to complete and then turn the ignition off. The fuel pump comes on for 3 to 5 seconds to charge the fuel rail. Now with a rag over the schraeder valve pres it in. You should get a large burst of fuel. If you get a trickle or no fuel then you need to start the troubleshooting for fuel.
Let the vehicle sit for a few minutes and the with the trunk open have a friend turn the ignition to on. You should be able to hear the fuel pump com on. If it doesn't then remove the fuel pump relay in the trunk fuse box and swap the relay with an identical one and try the pump again. You can also jumper the power at the relay spot to manually run the pump.
If you had good fuel then I would move on to check for spark. If you have no spark try removing and cleaning the Crankshaft Position Sensor.
Also have the battery load tested. If the battery drops to 11 volts during cranking the ECM will not give the command for spark.