So this has been plaguing me for months now. I bought my disco 2 6 months ago, it ran great, no issue. Then out of nowhere i got a miss on Cyl 1 and 7. Did plugs and wires, 7 went away and 1 stuck around. So I did the coil packs next, 1 still stuck around. I cleared the codes and drove it around light came back intermittent at random times. I just did a head gasket, the check engine light came back on, for the same miss I assumed, so I didn't think anything of it, been driving it for a few weeks, then all of the sudden on my way home from work the light starts flashing and I have next to no power. From a stop until about 1500-2000rpm you can feel the miss it vibrates really bad, then smooths out but still no power and the light keeps flashing. I got it home, was checking plug wires and number 2 shocked me there was a small hole in the top so I grabbed another wire and stuck it on, cleared the codes and went to go get my son. No codes for the 20 minutes of driving. Then about 5 minutes into the drive back flashing light again and the same symptoms. But instead of P0301 like before it's P0302 and P0300. At the same time I got P1884 and P0444 found my evap to have come unplugged because I stupidly lost the clip when doing the head gasket those codes have not come back yet, but the other 2 will not go away. I have taken the battery off and put it back on and they don't come back for about 25 minutes of driving just like before. Our weather just went from 20s-30s and today is the first day of 50+ don't know if that may have anything to do with it. But during the summer when it was hot my HDC light always came on too. I'm really hoping they aren't related and it's an ECU problem but I really don't know what else to do besides injectors. I absolutely love this vehicle and have wanted one for many years but I have been fighting problem after problem and I never get a break. I have the extinct relocation kit, it has good clearance problems I'm assuming that's not the issue unless I broke the coil pack shutting it the first time. Oh it's a 2000 4.0 also.


Few things I forgot to add. After the head gasket I must have tightened the bolts down wrong but I have a very slight exhaust leak, the code was for cyl 1 before the head gasket cyl 2 after. Before and after getting my son it was still 2 the way I typed it when I read it, I realized it sounded like it changed from 1-2 in the same day. But it did not. Could something as simple as a vaccum leak cause this?

 

Suggest you start here: https://landroverforums.com/forum/di...sfires-126863/

 

i will go swap plugs, drive it and if nothing happens ill swap wires and drive it and see if it changes at all to another cyl

 

went and got new plugs and wires, used a plug and a wire from one without a missfire, same result, then used a new plug and wire. same result.

 

Buying new parts is a hazardous troubleshooting technique. That was hazardous 50 years ago, and now parts are really bad and far too likely to be bad out of the box. The technique that Extinct pointed to is FAR superior to buying new parts because you have seen the swap parts working and can swap them back to prove that they still work. Use the swap method instead of the buy-new method any time you can. It also saves money and time.

 

Agreed. If the known good plug and wire gave a misfire, your next step is swapping coils. If that gives a misfire, you need to run a compression test and compare cylinders. If that checks out, you can swap injectors although I have never had a bad injector.