Dual fuel LPG problems

[seantaaffe]

every so often when im driving my check engine light comes on and the warning goes off on my dash display every time i check everything is ok, now i just keep driving and if i switch to petrol when its doing this the warning goes off. even asked my mechanic about it and he had no idea.
but. does any one have a theory or solution to the problem

[Brass Munky]

My old man has a 98 Jackaroo, was the first of this model to be fitted with LPG, from almost the day it was returned to us, when running on LPG, the Check Engine light is on, been a good 10 years now, and no real problems, people flip when they see it and get paranoid, but its normal for us..... We have a suspicion it has something to do with the Cat, pretty sure its rooted, but its only on LPG that the light is on, run it on petrol, and no light......

Dunno if that helps....

[blownba]

The reason this is happenening is due to the fact that a mixer system cannot control the LPG mixtures as accuratly as petrol injection can control them. So the petrol ECU detects that the fuel trims have drifted beyond a set limit and even though its trying to control the mixtures nothing it does makes a difference cause the ECU does not know its petrol injectors are switched off.
The way to get around this is to get your gas installer to fit a oxy fix module. What this does is provide the petrol ECU with a dummy oxy sensor signal when running on LPG so it thinks that the fuel mixtures are perfect. Thjis will stop the light from comming on. Dodgy fitters will not fit this or they will put a relay in that cuts off the check engine light when running on petrol, or even worse remove the check engine light globe.
Hope this helps.

[mmciau]

The reason this is happenening is due to the fact that a mixer system cannot control the LPG mixtures as accuratly as petrol injection can control them. So the petrol ECU detects that the fuel trims have drifted beyond a set limit and even though its trying to control the mixtures nothing it does makes a difference cause the ECU does not know its petrol injectors are switched off.
The way to get around this is to get your gas installer to fit a oxy fix module. What this does is provide the petrol ECU with a dummy oxy sensor signal when running on LPG so it thinks that the fuel mixtures are perfect. Thjis will stop the light from comming on. Dodgy fitters will not fit this or they will put a relay in that cuts off the check engine light when running on petrol, or even worse remove the check engine light globe.
Hope this helps.

Following on with what blownba has said, I had to have replaced my selection switch on the dash of the VS.

In doing so, the 'installer' had to remove the dash panel to access the rear of the dash so he could replace the switch with a non-original switch.

In doing so, there occurred a 'break' in the circuitry and as a consequence, the 'airbag' light came on at first start-up.

The 'installer' was completely stuffed and couldn't resolve the issue. (I wouldn't feed the so-and-so!!!)

A reputable auto electrician recognised the issue immediately and re-set the circuit using the electronic diagnostic/tester.


Mike