Poor idle on petrol startup

[Bigrig]

Can you start on gas or is it petrol only start with automatic changeover?

Tony

I normally start on petrol when it's cold as my LPG system doesn't do the whole squirt of petrol thing, and I don't risk it backfiring. On the odd occasion I have forgotten to change back and have started on gas, it hums, but not on petrol .. I let it warm up and then switch to gas.

[Bigrig]

I normally start on petrol when it's cold as my LPG system doesn't do the whole squirt of petrol thing, and I don't risk it backfiring. On the odd occasion I have forgotten to change back and have started on gas, it hums, but not on petrol .. I let it warm up and then switch to gas.

Thinking I'll go to Repco tomorrow morning and get one just to suss it out - would love it to be the coolant temp sensor, but still makes me wonder why two would go in the space of four months. I'll get some CRC MAF cleaner first though and give it a blast, just in case.

[YNOT]

Give it a try but I don't think that will be it, it would be affecting both fuels and would take longer for there to be enough heat increase to change its output signal.
What engine does Ryan have in his Patrol, you might be able to borrow his air flow meters to see what effect that has? You could also try his exhaust oxygen sensor.

Tony

[Bigrig]

Give it a try but I don't think that will be it, it would be affecting both fuels and would take longer for there to be enough heat increase to change its output signal.
What engine does Ryan have in his Patrol, you might be able to borrow his air flow meters to see what effect that has? You could also try his exhaust oxygen sensor.

Tony

That's true, but not sure he'll let me start pulling his car apart - he knows he'll get the crap part back!!! LOL ... I didn't realise the MAF affected gas as much? Or at least thought it affected petrol moreso. I'll give it a clean, and see if Derek is down the workshop in the morning and throw the diagnostic unit onto it ...

Thanks again