Power Loss when switched to Petrol after using LPG

[Bob]

I am almost ready to put my 1998 GU 4500 on the Market however I have a problem that I wish to fix before I do so.
If I run the Car on LPG for say 250 K’s and then switch to Petrol the Car will not accelerate and feels as though it is starving for Fuel. It would not pull the skin off a Custard. Very dangerous as I got caught whilst going through the Domain Tunnel in Melbourne towing my Jayco Dove and I was just able to pull out of the Tunnel . All I need to do is clean the MAF and disconnect the Battery for 30 minutes and the Car runs perfectly.
It is though the ECU is receiving Data from the MAF sensor when running on Gas and using those settings when switched to Petrol.
The Car runs perfectly when I reset the ECU and clean the MAF and I obtain the following Fuel Usuage:-
Petrol 16/18 L per 100 K’s
Gas 18 Litres per 100 K’s on a Trip and 22 Litres per 100 K’s around town and when towing my Jayco Dove
Does anybody have any clues

[NissanGQ4.2]

I think its just the GU's was of saying its not time 2 go Bob.

Sorry can't help you on this one mate, hope you get it all sorted

[YNOT]

G'day Bob.

It could be that your gas control system is not set up to respond to the exhaust oxygen (02) sensor and the gas system is set up too rich.
All gas systems on EFI cars are by law required to operate in closed loop where the mixtures are monitered by the 02 sensor and adjusted accordingly, however not all systems are set up properly. The result if the system is not set up correctly is that while the engine is running on gas the original petrol ECU which thinks the car is still running on petrol, will be constantly trying to lean out the mixtures.
The adaptive strategy in the petrol ECU stores the adjusted mixture settings/parameters in a temporary memory, which is reset when you disconnect the battery.

Tony

[Bob]

Thanks Tony.
Will take to a LPG specialist and advise him as per your Post.