Land Rover Repair: 99 disco2 acceleration problem, th cd, resitance

Question
ya sorry for not enough  info. The disco is idling a little bit rougher, as it wasn't noticeable before. The service engine light is on and when i put the obd2 on it, it came back saying there was a misfire in cylinder 3,5,7 as well as something was to lean a mixture.
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-----Question-----
hey Bruno, My Disco 2 is running well other than when i push the pedal all the way to the metal, it doesn't accelerate. the Rpm goes up but no juice. Also i just noticed today that the spark plugs look rusty, would that affect this. one more problem, it seems there is a cd stuck in the player, any quick fix. thanks a lot Ben
-----Answer-----
Hello Ben,
There might be numerous causes why you're disco is not running right.
But I need more info.
Does the motor misfire when the problem occurs?
Is there a Check Engine light on or did it ever come on?
Does the motor idle ok?
As for the stuck CD, there is only one way to get it out.That  is to remove th cd player from the vehicle and to dismantle the cd player to get the cd back.
Hope I can help you
Bruno

Answer
Hello Ben,
It's a bit difficult for me to tell you exactly what is wrong with your Disco since I can't perform tests on it, but I can tell you what I have encountered the most on Discos.
You should try the cheapest way first and replace all your spark plugs.If the motor still misfires after you replaced the plugs then you should have a look  at the wires.Not really easy since the coil back is sandwiched between the firewall and the engine. Only remove one wire at a time so you don't mix them up.Resistance of the wires should be between 6000 to 8000ohms a foot.
Also look inside the wire boots for signs of corrosion.
If the wires have high resitance or are corroded replace them.If after eliminating the wires the motor still misfires then further tests are required and a qualified technician should test the compression and fuel system and make sure your motor doesn't suffer from sticking valves.
I hope this information helps.
Bruno