hairyape1
04-14-2018, 09:38 AM
Hi All, I have in interesting problem with my allroad.
It has an lpg kit fitted and I normally run on gas, but i had noticed that mpg was not that great when running on petrol even if i drive it really careful I would only get 15-18mpg on a run. I first became aware of an issue when the car had an lpg service and the mechanic noticed that the settings for the lpg were strange. Investigating further they noticed that the fuel trims were not moving in gas or petrol. It turns out the lpg has been leaned off to make it run better on lpg because the engine was running rich.
The engine was running rich because the fuel trims were not moving.
Checking vcds showed no movement or voltage on the lambda sensors, they are all reading 0.000v. So im guessing the fuel trims arent moving because the engine is getting nothing back from the lambdas. And hopefully by getting them working again I will improve petrol mpg and be able to run the lpg on normal settings as it can now follow the trims.
What is strange is that I have no fault codes/CEL.
Could it be that the lambdas have been mapped out?
Where is the best place to start looking for the root cause?
Thanks
It has an lpg kit fitted and I normally run on gas, but i had noticed that mpg was not that great when running on petrol even if i drive it really careful I would only get 15-18mpg on a run. I first became aware of an issue when the car had an lpg service and the mechanic noticed that the settings for the lpg were strange. Investigating further they noticed that the fuel trims were not moving in gas or petrol. It turns out the lpg has been leaned off to make it run better on lpg because the engine was running rich.
The engine was running rich because the fuel trims were not moving.
Checking vcds showed no movement or voltage on the lambda sensors, they are all reading 0.000v. So im guessing the fuel trims arent moving because the engine is getting nothing back from the lambdas. And hopefully by getting them working again I will improve petrol mpg and be able to run the lpg on normal settings as it can now follow the trims.
What is strange is that I have no fault codes/CEL.
Could it be that the lambdas have been mapped out?
Where is the best place to start looking for the root cause?
Thanks