I started having issues a week ago with misfires. It started with the code for the number 1 cyl and then spread to the rest of the cyl. including a code of 1300. I changed the plugs with Champion platinums (same as what had been in it). The old plugs were shot, as most of them were burnt down to nothing. After changing them it threw codes 305, 308 and 1300. I cleared it again and drove it to the end of my drive way (2 miles) and then drove back. Now it shows a code of 305. My Disco is an 04, and I will need to remove a bunch of stuff to change the wires as I can't get my hand back to the coil. I have a new set of magnacores to put on, but also ordered a new coil pack. Since I have to tear into it, I figure I might as well put a new one on. Does this sound like I am taking the right path or do you think something else is causing the missfires? I just purchased the rig a month ago so I don't know the history of what all has been done to it in the past. It ran like a champ until the weather warmed up. Thanks for any help.

 

Plugs and wires certainly cure most misfires. If taking off the top section of manifold, consider testing fuel pressure also, the test point will be easy to get at. #9 in attached drawing from RAVE manual set, which you should have downloaded.

 

Also check your air filter

 

Chance are you do not need the coil pack, I would send it back and save that money for a new front drive shaft or some other project on your truck.

 

Thanks everyone. I am still going to replace the coil pack. I don't want to run the risk of having to tear it down twice. Plus I work in some remote areas so replacing some of the items like this is probably not a bad idea as it is one less thing to go wrong. I will update once I figure it out.

 

Another "remote area" item to consider would be the crank position sensor, or at least carry a spare...

 

I took your advice in the welcome area of this board earlier and ordered one already. Good to have a few things on hand in a pinch. So far it has been a great rig other than this issue. I have had it in some nasty areas and it crawled right through. One of the construction crew almost got his 3/4 ton chevy stuck and told me I would never get through. Heck it never even bogged down. Now it is just a matter of fixing all the small stuff everyone ignored prior to me owning it. Kind of fun as it has been a while since I have worked on anything. I used to race cars in my earlier days and now trying to remember how to do some of this stuff again. The main difference now is dealing with all these sensors. All of my cars were from the 60s.

 

Well yesterday I finally had time to dig into my Disco, so I thought I would give an update. It was giving codes for the 5 and 8 cyl misfires which I have read are paired and indicate a bad coil if both are missing. I had ordered a new coil pack and sparkplug wires. Once I got everything off, I found that a darn mouse had crawled back in there and chewed off the two plug wires. Well I got everything replaced and since reaching the coil is a giant pain I installed the new packs and saved the old ones for spares. She runs like a champ again! I think it is time to get some mouse poison out in the garage.