Hi guys,

I'm a bit new to Range Rovers - I've got a 94 P38 4.6HSE - and I'm very new on here.

My Range Rover was without a battery for about 24 hours and after a new one was fitted it runs rough and has lost a lot of power. I've checked the plugs and leads and it's running on 8 cyclinders OK, but it's as if the timing has gone to pot. I'm guessing that the ignition timing is controlled by the ECU - and if so could it have lost the mapping whilst the battery was out and defaulted back to a factory setting or am I way off the mark here?

 

I'd go with the remapping,if it ran good b/4 batt change.
You may want to look for excuses to keep running to the store and drive it through it's full range.
I believe the more you excercise the ecu the faster it'll learn.
Just my thought.

 

Thanks - I've been on a long run and it doesn't seem to make any difference. I'm not sure if the ECU works in that 'learning' that way as surely it would need some sort of feedback loop to learn from - perhaps the lamda sensors - don't know? I'm guessing that it needs to be set up using Rovacom or some such sofware.

By chance I hadn't used the RR for a few weeks and yesterday the battery was dead flat. After a charge it started OK but ran very rough and wouldn't idle - it got a bit better after a few minutes and idled without stalling but still runs rough. I'll take it out for a run today and see if it gets any better.