Problems running on LPG During warmup

[bornville]

Hi
Wondering if anyone could help me. I've just installed a new LPG LECHO system on Audi A8 V6 3.0.

The car runs fine on gas and petrol when the car is fully upto temperature about 90 deg.

The car is set to change automatically to lpg at 35 deg. At first the car would bang when accelerating.

A friend of mine told me to change the spark plugs to iridium as this would cure the problem.

It has improved but still not 100%.

The vaporise is sized from 350 bhp so should be well in.

Any ideas?
many thanks in advance
Barry

[sijones]

In my simple opinion.... Incorrect tuning, maybe too rich during warm up due to the ecu adding extra petrol in which will be too much gas mixture and therefore cause misfiring etc..

Had it when i first did mine.

[hardcorepit80]

Problem with warmup comes up in some audi and wv engines(petrol ECU extend inj. times during warmup and gas ECU can't cope with it witch leads to rich mixture).I felt that a bit on my a8(same engine as yours) but managed to clear it by playing with temp. correction, rpm correction and stag's "cold engine leaning " option for VAG cars.
Prins have (or had) temp. emulator to sort it out, witch I made, but never use.
I think the worst thing you've done is change Stag to Lecho... I've never played with it but it has bad reviews( apparently it's very hard to set up and tune)

[tommo2009]

Alter the change over temp to 50 and see if the problem goes away. could be the extended warmup as mentioned or could just be a simple tuning issue.