2001 Disco 2 runs very rough

[ando98]

Hi all, before you ask, NO, I don't have any codes. The only person with the tech to read the codes is 80 clicks away, so I haven't got anything more than what you read below at this stage. Since a major beach excursion a few months ago, my Disco 2 - 2001 V8 has started running roughly. It's gotten worse recently and I thought it might have been related to the failed CPS that I just replaced. However, once the CPS was replaced, the car starts just fine now, but appears to misfire under load (ie, at intersections) or when cruising around town.. it's definitely noticeable to everyone on board. I've looked at a bunch of other posts, but I really have no clue what it could be. I'm just looking for possible suggestions that I can take to my mechanic and have him try.. Thanks in advance! Ando!

[handsome rob]

So does it misfire and then the service engine light goes out? Or does the light not come on at all. You may just need some new plug wires and are having some arcing going on.

[Disco Mike]

A crank sensor will not cause a rough running engine, only a no start or hot start problem.
When was your engine last tuned along with new 8 mm silicone wires, have you checked/cleaned or replaced your air filter and what octane gas are you burning?

[ando98]

Originally Posted by Disco Mike

A crank sensor will not cause a rough running engine, only a no start or hot start problem.
When was your engine last tuned along with new 8 mm silicone wires, have you checked/cleaned or replaced your air filter and what octane gas are you burning?

Hi both!

Thanks for the fast response. To answer the first question, the "check engine" light does not illuminate.

For the second question, it was last serviced about a month ago where they air filter was replaced (I have visually confirmed this) but I am unsure if they replaced the spark plug cables or performed a tune up. As to the octane gas, I'm running 98 octane PULP.

What's your recommendation?

[Spike555]

Does the check engine light not work? Does it come on and do the self test when you turn the key on but do not start the engine?
This sounds like a classic in the need of a good tune up.
The other thing could be corroded O2 sensors, I'm guessing your beach excursion was driving in salt water?

[Disco Mike]

98 octane, God, I would kill for a tank of that, best I can get in Colorado is 91.
What color are your plug wires? If they are grey, they should be replaced along with plugs it they check out to be old also.

[ando98]

Originally Posted by Spike555

Does the check engine light not work? Does it come on and do the self test when you turn the key on but do not start the engine?
This sounds like a classic in the need of a good tune up.
The other thing could be corroded O2 sensors, I'm guessing your beach excursion was driving in salt water?

Hi Spike,

Yes indeed! We got seriously bogged in the dunes (a long way from the actual shore) and took us quite a few hours to get out. Are the O2 sensors the ones you can see just before catalytic converters on the exhaust? Oh and yes, the light comes on during the self test but does not illuminate once the car has been started.

And to Disco Mike.. If I could send you a tank full of 98 octane, I would . I will look into replacing the leads and the plugs.. that's a very good idea!

[Spike555]

Yes the O2 sensors are the screw in things with wires coming out of them just infront of the catalytic converters.

[ando98]

just a quick update. The price for 8 plugs is $200 and new leads is $115. Labour is not included, so we'll have to see what the final bill is and let you know. Should be done by this Thursday, so will post back then!

[Spike555]

I cant believe the price of parts down there!!
Here I can get 8 spark plugs for $12.
Installing spark plugs is easy, doing the plug wires on a DII is not, but if you check the write up section it will tell you how.