Range Rovers Forum banner

Bad running engine

2427 Views 9 Replies 7 Participants Last post by  rangeroverklaas
Hi there,

4.6 HSE 1999 with bosch motronic with engine problem.
Faultmate ODB P0172 and P0175 say both cilinder banks lean mixture.
Also misfire at specially at nr 7, have change HT lead and plugs, no result.
Engine hesitates during acceleration.
I guess the misfire is a result of the lean mixture.
On petrol less misfire then at LPG.
It's not every day very bad, cold weather and cold engine is worse.
Something to do with an airleak after MAF sensor? , broken inlet manifold ?



1 - 1 of 10 Posts

You do not state if your LPG system is single point or multi point injection nor if you have any controller open or closed loop installed. A closed loop system should correct the lean mixture. Check your pressure settings of the LPG at the evaporator. With cold engine the evaporator doesn´t work so well either which can explain the increased problems.

From what I have read on this forum I believe that running on LPG will upset the petrol ecu adaptive settings as the ecu signals are bypassed during LPG usage and the engine doesn´t repond to petrol ecu outputs. Try resetting the adaptive values as this might cure the lean problem during petrol operation.

You might want to PM Alley V8 as he is the expert in this field.


1 - 1 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.