Timing??

[Demondad]

Just got my diagnostic software going and have noticed my ign timing is about 15.5deg BTDC the help menu on the software says should be 17-22 at 950 idle speed. Are 4.2s the same as 4.5s in this spec? As its due for a 6K service am I best to leave alone or is timing a DIY? She is running lumpy. Like missing a cylinder or something but nothing shows in faults except timing and maybe slightly out throttles 1-2%. I have checked as many spark plugs as poss but rear NS is a B******D so left alone. Need a slim plug spanner. Would love to get her together for Goodwood gather. Advice?

[jbvipercerb]

You can't directly alter the timming, its altered by the ecu. The ecu could be altering the timming because of the lumpy running and if the throttle pots aren't adjusted correctly the ecu will try to compensate any way it can.
Try adjusting the throttle pots to the correct settings and then see what the timming is

[Demondad]

jbvipercerb said:

Try adjusting the throttle pots to the correct settings and then see what the timming is

Thanks for replying! So if the ecu does the timing is it simple to adjust throttle pots? Or leave to service. I'm not bad with the spanners.

[350Matt]

If its going in for a service they should set the pots up
However its an reasonably OK job to do yourself

You'll need a flow meter or carbalancer to balance the airflow on both banks first, then set-up the pots so they give the correct values.

The help file on the laptop program tells what the values should be

Matt

[Demondad]

Thanks Matt, will have to have a go, got to get to Goodwood.

[julian64]

The only thing I would add to that is that the flowmeter doesn't help you that much unless you have a problem with one of the cylinder which the flowmeter might tell you.

I wouldn't personnally bother with the flow meter. Just use your diagnostic software to set the two potentiometers within range first then use the adaptives for fine tuning the pots side to side and the 90 degree angle of the butterflies at 94% odd for up and down.