Jaguar Repair: ignition timing

Question
Hi I have a 1975 xj6 4.2L jaguar and it runs and everything but the timing is alittle off I was wondering if u could tell me what exactly the timing should be if you could that would help alot

Answer
Hi Jamie,

There were two different series 2 XJ-6 4.2 Jag settings in 1975. If it had Kettering ignition (points) it set at 10 deg BTDC at 1000 RPM. If it was a Calif. car it had electronic ignition and that set at TDC at 1700 RPM.

If the sticker is still under the hood, the setting noted there always over rode the book specs.

On the older cars I noted that some may have had the head resurfaced and thus changing the compression ratio which alters the needed ignition timing, plus the different grades of gasoline available today so that makes it necessary to alter ignition timing. If when the engine is fully heated up and any "Pinging" is noted when heavy throttle is applied at low RPM, you need to retard the timing in 5 degree steps until it stops Pinging. Then that will be your new timing necessary.

Howard