AU1 Rough Idle

[Flyn]

I have an AU1 on dual fuel. It idles reasonably well on LPG, but very rough on petrol. Actually, it's never idled really smoothly on LPG or petrol, but now it's missing badly on petrol.

The mechanic said he thought it was a coil pack problem, but surely this would affect both LPG and petrol? I put some inject cleaner through and I also run it regularly on petrol, but still missing when idling.

Another thing is that it always idles very roughly on both LPG and Petrol when starting up in cold weather. This doesn't come good until I've driven about 15Km...well after the temp gauge shows normal operating termperature.

Any ideas?

[blueoval]

could be filters, plugs, leads.

You need to get it diagnosed.

[EvilChief]

LPG always masks ignition and idle problems. so if u r to diagnose an ignition and or idle problem, always do it on Petrol.

id start by looking at sprak plugs and see which cylinder is missing, the move along teh leads, etc

[Deevo209]

hi guys,
just been reading through all the threads regarding idle probs. I too have these idle probs, and recently had my Au ute converted to LPG. (terrible install too!). Whilst Ilde has been erratic prior to gas conversion, it's now amplified the prob (only when running on gas). I've installed new leads, plugs, O2 sensor, fuel filter, Injectors sound good on a stethoscope, cleaned throttle body, IAC valve works fine.
haven't tested the coil pack (if they can be tested). I'll just keep following the threads until something pops up.