Hi all first time poster,

I have an issue that I have been trying to fix.

Vehicle: 2000 Discovery II
Mileage: 136,000

Here are the codes:

P0444 Purge Valve Open Circuit
I replaced the purge Valve with a new one.
P0446 CVS Valve/Pipe Blocked
Took apart the valve and it looks good also tested it directly with power
P0305 Cyl 6 Misfire
I get this one all the time same cylinder

P01590 Cleared these codes with AmigoUSB

The misfire showed up last week and happened in the morning once engine was at operating temp it seemed to disappear. It has progressively gotten worse and now the engine misfires almost all the time and the MIL light blinks.

I have replaced the purge valve, cleaned out the CVS Valve, the power pack was changed in May 2011, have examined and reinserted the plug wires at a loss here. Any advice would be great.

 

Sorry,

Patrick Hunter

 

Would strongly consider new plugs, perhaps new wires, if not changed in recent memory.

 

What is the lifespan of wires and plugs?
They have been replaced with the last 4 years with Bosch Plugs and the recommended plug wires. In other vehicles they have gone for 5 -10 years without issues.

Thanks for answering,

Patrick Hunter

 

Well, as you know, this is not like other modern vehicles. More like a 60's station wagon engine with modern electronics. I have seen posts of 30K for plugs.

That aside, plugs are one of the cheapest fixes out there, and you know you will need them at some point. You could just remove the problem one, and inspect it for color of the tip, etc. Replace with a new one, see if problem goes away. Could swap plug wire with another cylinder (both ends), and see if problem moves to another cylinder. Then you can decide if problem is in the ignition area, or if you need to look for other things.

 

You are right. I have Disco in for Service now. I do not have the time today to work it so I will have to hire it out this time. Will let the forum know the result.

Thanks.
Patrick

 

Mechanic replaced plugs and wires. So far engine runs fine and the emissions codes seemed to have disappeared as well.

Thank you all for the answers.

Patrick

 

Old Skool Rules. BAck in the 70's guys would buy plugs by the case...

 

Take more time and do some of the work and or at least be involved in the selection of parts you have installed on your truck.
Whos plugs and wires did the shop install, the wires can make a huge difference in how the truck runs.
Have you been having to add coolant to your truck lately?

 

I had similar stumbling and the dealer told me it was wires and coils which they replaced... after joining here I realized they probably left old plugs in.. Ill check today.. anyway..I also realized there is a common wire here people like.. magna core or something? I can't find reference now when I need to know! lol anyway,Im thinking of replacing them also this week with new plugs... any suggestions on plugs and wires? also they said its you have to remove intake to change coils and Im assuming yup... however... can I replace plugs wires without removing intake?..

[UPDATE] DiscoMike I just found your post on another thread and found this 8 mm STI wires I see on their website they say to 02 discovery.. but they also say 4.6 so I don't know if they are the right ones or not...?? nice site at British Utah though! THANKS!