What is going on ?

Don't go synergy without fixing the fault - I did and have spent months chasing problems - mine is off again going for diagnostic tomorrow.

Good point.

I drove it to Limoge Airport yesterday after fitting the new MAF, 220 kilometre round trip and it never missed a beat.

Fingers crossed.

Is the MAF brand new in the box? If not it could be out of spec.

Try putting some injector cleaner through it - Millers is the recommended on this forum - I use it and it works well.

I found performance improved when I changed the crankcase filter for the BMW one and also went to Fully Synthetic oil - seems odd but it made a difference.

Adding a Synergy might only mask the problem that you have.

These engines pull quite well but I am not sure what you are comparing it with - they don't rev very high do you use the torque not revs to get performance.

If a is good then a Synergy makes it even better.

Another thought - you say the garage checked injectors - to do this correctly you have to remove them and get them on a Bosch test rig - there are differing modes of fuel delivery and if the initial per injection and low delivery is missing it may not show up in a Leakback test.

How many miles has it done?

MAF is brand new.

Millers is in the tank.

Injectors were not removed just a leak-down test done.

Vehicle has done 100,000 miles.

I did a full service after we bought it including the crankcase breather.

As I said earlier it worked fine yesterday so I'll just drive it around for a few days and see how it goes.

I've not driven another FL to compare it with so I may be expecting too much especially given that it replaced my old 4 litre petrol Jeep.

The injectors are at the end of their life - it seems they are ok for about 80k miles to 100k miles - thing about an injector test if the issue continues - cost is about £20 per injector but you have to get them out.

I'll ring the previous owner and ask him if he has had anything done with them.

He has certainly kept up with servicing and stuff and many items have been replaced when needed.

Thanks for all the advice, much appreciated.

Gary.

River Ron himself says injectors should be considered consumables and changed at 80k miles - in his instructions he stresses that a good condition fueling system is essential or the synergy will make things worse!

my injectors seem fine they have done 170000 but I am touching wood the last time I said somthing I had a problem

That's great you have obviously looked after them and used good fuel or you are very lucky. They are probably not working to their best though at that mileage - any smoke? What mpg are you getting?