Faulty plugs/OBDII code

[clieman]

If I had one or more fouling plugs, wouldn't the computer send out a code indicating a misfire for a particular cylinder?I have rought idle and now the engine is missing when its in a high gear and under little load.

01 disco2.

 

[joey]

Normally it would send a code, but this is a LR and anything is possible. If you haven't done a tune up in a year or so.... then I would start by changing the plugs (remember the rover likes cheap champion plugs)

 

[clieman]

Yea, what is the deal with the plugs?The ones listed in the manual aren't available anymore (at least not with that part #).And people are telling me that they are double platinum from the factory. They didnt have the champion plats at Kragen, so I ended up with bosch plats. Actually changed them yesterday, havent got to drive it arround yet, but the idle seems better. One of the plug wires had some white powder type residue between it and the plug, cleaned it out with WD-40, all the other wires seemed ok. Plugs werent terrible, but definately old and probably factory. Plus, (gasp) the # 3 & 4 cylinder plugs had some oil on the threads...
Think the wires need replacing (55k)? Quite a job to change them if not really necessary.

 

[webbie]

Autozone has the Champion 318 spark plugs in stock costing $2.67. As my task for this morning is change mine. Hopfully this will help fix a misfire.

 

[clieman]

DAMN! Got a chance to drive it today, started fine, good idle, started out smooth while driving. Got about halfway to my destination (about 5 miles) and felt some hesitation. Then the stupid check service engine soon light came on. Same thing happened before, but the light went away and the bad idle remained. And, of course, last time there was no code in the computer. So, now I have to go to autozone to use the tool and hopefully get a readout this time.
Idle is better now, but not perfect.Only jumps arround a little now.

 

[clieman]

SWEET! Ok, got to read the codes. Sure enough, #4 cylinder misfire. The same wire that had the corrosion in it. Guess thats as simple an explanation as Im gonna get!