I just recently bought a beautiful 2003 LR disco with 118,000 miles on it and had recently had the head gaskets replaced. I bought it and trailered it home put a new battery in it and it starts up but idles really rough and has misfires on cylinder #'s 3,5,6, and 7!!! any help would be great thanks and I am new to Land Rovers and this Forum. I bought it from a buddy and the last time he drove it everything was great and then the next morning he started it and it ran really rough. So he left it parked for a couple of weeks and then I bought it. And it is just odd to me that you would get a misfire on one cylinder on one bank and then 3 cylinders on the other side. I just don't get it and I don't want to sink a bunch of money into this motor when I have already found another one.

 

How old are the wires? I just had misfires on 1 and 6 leading me to believe it was a bad coil...but new wires fixed my issue. You have misfires from both coil packs, which I think would be odd to have both packs go bad at once. If you can reach back to the coils, try and make sure the wires are plugged in firmly. If you have secondary air injection (SAI) you won't be able to get to all the output terminals on the packs. Obviously check at the plug ends too.

 

The plugs and wires were only about 2 months old but to be safe I went ahead and replaced them all yesterday. it did make a little better but cylinders 1,3,5,7 are lean and cylinders 2,4,6,8 are very rich and after watching the O2 sensors jump all over the place for a while and when they were not jumping around both #2 o2 sensors were at 99.2 V and #1 sensors were at 25.0 V and when I unplugged the sensors it made no difference on how she ran. And yes I do have the SAI.

 

And if I pump the throttle pedal real fast the engine will rev up but if I push it slow she just sputters and dies. does anyone know where the fuel filter is or is it in the tank?

 

I had that problem and it was the coil pack.You have to remove the upper intake to replace the coil pack on the 01 discovery.