4ltr straight 6 timing

[Mudgee hunter]

Im well aware these motors have a pcm regulated timing etc.
Thus it has fixed dizzy position.
But what really is the degree etc.
They do have timing marks etc.

[awg]

The PCM would have a programmed ignition map

I havent seen anything published that shows the advance curve

[Mudgee hunter]

Tnanx, I would like to know what it should be at a warm idol etc. I'm finding 10 deg is average.

[awg]

Originally Posted by Mudgee hunter

Tnanx, I would like to know what it should be at a warm idol etc. I'm finding 10 deg is average.

When you are timing it from the pulley damper with a light ?

On the Jag 4.2 I6, I marked the damper with different nail polishes, at 10* intervals and it runs 10* at idle, and is all in at 35* 3500rpm

As you would understand a PCM MAP would vary a lot with load etc etc

A lot of guys have fitted computerised engine management for the older vehicles with pre-OBD technology, and used to pre-set map for that vehicle or written maps based on others

[alexbrown64]

Mine always has about 14* of advance when she is running at hot idle.



Reading around the forums, seems 10-14 is the general range.

Cheers,

[awg]

from my fairly limited readings, any attempt to alter timing will be fought by the PCM map.

As I understand it, on an XJ, any alteration whatsoever of the exact dizzy physical position will cause either poor, or no running

[emac]

its not possible, you do a static timing , if its been apart and the computer does the rest. that's it

and why would you have it apart, my "94 has 460,000 km on it and the distributor has never been touched.

if you have swapped an engine or done a rebuild there is a static setup you do and then your all good.

the only difference in RENIX era cars, and we didn't get them in AUS