Hi, I have a land rover discovery 4ltr V8 X Reg (year 2000) and was a great 4x4 until several months ago!

We started to notice power loss, when requesting power the revs would get to around 3000rpm then stop! She would also sometimes miss fire and judder.

So we did the normal new sparks plugs and leads but no difference, then one day she broke down and would not move! The RAC came out and there said the car had a right hand bank failure and suspect compression/head gasket issue.

So as a result we had the car booked in to a land rover garage there did some tests, to cut a long story it seemed we had a blocked CAT which was due to an over heat and also a compression fault within the engine, then to top that all off a bent manifold! Caused by the overheat! Oh Joy!

So 4 months later after an engine rebuild! Crazy?? We had the following done

New Cat
New Ignition Leads and sparks (again)
Valve repair to the Cylinder Heads
New manifold
New coil packs
New O2 bank sensors on both banks

She was now rebuilt and running again! But wait there is more……. The land rover diags show that the car was not also firing evenly on all 8 cylinders!???! And as a result would some times judder or miss fire! (The same as several months ago! Surely not this again!! )

So back to the garage the car went and there did a complete electrical test including the ECU and there found that the ECU was not working correctly (something to do with the fuel trims) which the ECU controls . I was also told that the ECU learns this information and the ECU will try to of set any issues that happens with the car such any the miss firing etc, as a result the ECU would still be thinking the car has miss fire issues and the only way to fix this is to drive the car for 500miles while the ECU re learns and programs to the correct fuel trims of my car!!?? (Can this really happen?)

So my question has anyone ever heard of this? Or had the same problems!! Many Thanks

cant help yu on your problem, but intrigued as to why yu need to post twice on the subject?

did not mean to, my internet explorer crashed

Yup, I've been told this by 3 different garages, I'm having a problem with my LPG running lean and the cars Bosch ECU is trying to correct the gas (something it has no control over) I was advised that before I try to tune up my LPG to switch to petrol and run for 40-50 miles for the ECU to relearn itself to the best setting for petrol then to tune up the gas, had me gas tuned up and was advised it might be nescessery to have the adaptive fuel trims (petrol) on the cars ECU set back to factory setting but was warned it would cause rough running for at least 100 miles

give it time, if after a couple of hundred miles it's still not right, take it back

If the fuel trims have been pulled so far out due to rough running/misfire it could take some time to learn itself back to where it should be

Take it easy with a rebuilt engine too, everything will need 'run in' for the first few hundred to 1000 miles

had this sort of problem but ours died when coming to a stop and it was the air flow sensor on ours and now shes running sweet agin