3.5 Efi Hotwire Timing

[disco_al]

I need to check my ignition timing this weekend on the 3.5 efi (hotwire). It's been behaving strangely for about a week now, so i have ordered an inductive pickup timing light ready for the job.

The plugs are NGK (I won't use anything else), gap has been narrowed to ignite the gas better, new cap, arm and leads were all fitted when i did the head gaskets (2 months ago) and are all in good condition. She has been idling lumpy, when started it revs up to about 1600rpm before settling back to a rather lumpier than normal tickover. When it switches to gas it runs just as well as on petrol, similar symptoms though, lumpy tickover, and it also tends to hover at about 1500rpm for a few seconds before returning to about 900-950rpm.

So, i will check the timing this weekend just to make sure it's all ok, so, does anyone know what the timing should be on a 3.5 on gas (it's the 9.35:1 CR engine too)? I have been told anything from 6 to 12 deg should be fine, but wanted to consult the guru's before commiting to something that's going to break my engine.....

cheers all

[Bull Bar Cowboy]

Ideally about 10 to 14 degrees more than petrol......................

The plug gap should be the largest that you can achieve with reliable firing.

If you are running both petrol and gas and not using an intelligent ignition amp (an amp that adds in the extra advance automatically), then advance the ign timing until it pinks under load on petrol, then back it off a degree or two...........

Ian

[disco_al]

cheers for that, i tend to only use the petrol for start up, 99% of the time it's on LPG.