Trying my best to get to the bottom of this.Any advice appreciated
Fault started a few weeks ago. BIG misfire in 3rd gear around 60mph (3-4k revs). Apart from this, the car appeared to drive fine. Since then the fault is occuring more frequently. Car seems hesitant and occasionally the spanner light comes on.This can happen randomly but more often than not on the motorway even without a misfire. Car has went into limp mode a few times, but after restarting the car, this clears. Building up speed slowly is fine but driving 'hard' the car seems sluggish.
I took my spark plugs out and number 3 plug (3rd from LHS looking at front of the car) appeared a bit 'burnt' compared to the others. I swapped the plugs with my old ones and the fault was still there.
Up to now I have tried (some of which were just routine)
Oil and filter
Changing spark plugs
Wynns EGR cleaner
Wynns Fuel system cleaner
Shell petrol (instead of supermarket)
None of this has made any difference.Last year the O2 sensor and the High Pressure Fuel pump were changed and the engine block was changed due to a major mechanical issue.All of this was done under Warranty.
The P1191 points to a fuel rail malfunction. I appreciate that this fault may be hard to pinpoint but from what I gather so far, it could be the high pressure fuel pump (again) as a newer,improved pump did not surface until mid 2008 and mine was replaced January 2008, the coil pack, the fuel pressure regulator or perhaps an injector.
When the car was hooked up to diagnostic equipment in a friend's garage, it showed the fuel request Vs delivery and at idle and when revved, these matched fine. My mate did say though that as the car effectively isnt under load, it would be hard to replicate the exact fault. My concern is that the car is not showing the same symptoms of when the pump went the last time.In this instance the car had literally no power above 30 mph in every gear. I can get a diagnostic done at the Dealer for £45 but my concern is that they wont be able to pinpoint what is wrong and will only advise on the fault (which is really where I am now). i.e it could be............
Sorry about the speel