So about a month ago, after doing a tune up, I started getting the CEL saying misfiring. and the car was running not at it's best. I had just replaced the spark plugs prior to the CEL so was hesitant to change them again, but i did. I didn't realize that doing an induction cleaning after installing new spark plugs was stupid, and it would foul them. So I replaced them a second time beginning of the week, or sometime last week. Drove for about two days, and the CEL turned off, and everything was fine, back to normal. This morning the CEL came on again, and i had it checked, same thing. Misfires. I just put in new spark plug wires probably the first week of January. So i don't think it could be the wires. I don't know what to do next. The car is running fine, except for the fact that it's apparently misfiring.

98 discovery le
139000 miles

 

what are the exact error codes you are getting? have you double checked you didnt cross the wires during install?

 

cylinder 8 misfire
general multiple cylinder misfire

I don't remember the exact code, but that was the description for them.
I'll probably go up there after 12 tomorrow and have them print it off for me.

when i replaced the wires, I did them one at a time, to make sure i didn't mix any of them up.

 

Cylinder 8 could be a head gasket leak, are you losing any coolant? Pull that plug and see what it looks in there. What kind of wires did you use?

 

no, i'm not loosing any coolant, Using 45 dollar wires i bought from advance auto...can't remember name of them. I wanted to order magnecore, but i'm on a base, and mail here is so sketchy, I didn't want to have to track it down once it got on base.

 

My money is on the wires. Order kingsborne 8mm wires they are cheap and good quality.

 

they were Accel plug wires for 40.99

 

You need new wires.

 

Swap 7 and 8 wires and see if the misfire moves or buy a new wire.

 

2X ON SWAPING THE WIRES ON A COUPLE OF CYLINDERS......to see if the problem moves with the wire or stays with the cylinder, and then ..........here's a far out shot in the dark......I had the same problem with my DI when I first got it, I did everything plugs , wires connections etc etc, I purchased a new ignition coil to try that route (even though it didnt make any sense) AND THEN.....as I was hooking up the wires to the new coil I noticed a strange non factory looking wire twisted and just electrical taped to one of the coil wires, I un hooked this and repaired the wire to the coil.....no more codes ( from that lol) .........someone had tryed to install a cheap alarm system at some time and tapped into the ignition at this point...after following the wire to under the dash I found a real mess there too .......so it is possible your problem is a previous owner's attempt at something ?.
good luck and keep us posted.