Rough idle/stumble

[clieman]

Hello all,
I know this has been mentioned, but I cant find any threads that have the same symptoms as my 01 Disco II. Just a slight, periodic stumble while idling, and every once in a while a significant hesitation/stumble while the truck is in a higher gear but im only giving it a little gas and not going very fast (probably around 35-45 MPH). Under full throttle and cruising speeds no stumble at all, very strong.

Thought this was due to using 50/50 tankful of 89 & 91 octane, but filled up completely with 91 and some of that OEM Rover fuel system conditioner. Symptoms have only let up slightly.

All came on kinda sudden, too. About 2 weeks ago.

Thanks.

 

[joey]

A little back ground on maintenance history please. I am sure it has been mentioned in another thread, but the basics always help.

 

[DirtyDisco]

how old are your spark plugs, air filter, that type of thing?

 

[clieman]

couldn't really say, I got it used only about 6 months ago. Looks like the previous owner kept it up though. OEM oil filter, service campaign decals (would be curious to know what those were for and if anything else is available), and all fluids were clean (changed ALL fluids when i got it). Its got about 55k on it now, couldn't say about the plugs and wires, will look and get back.Would change fuel filter, but LR had the brilliant idea to put it in the fuel tank (not so easy now)...

Thing is this started happening out of nowhere. I was using 89 octane intermittently before, with no problems.

Ill take a look at the plugs and stuff this weekend, and ill probably also clean that valve on the top-middle of the engine (herd about it on another post, dont remember name).

 

[clieman]

OMT, the air filter is new.

 

[Eekie]

My 04 Disco does the same thing. Seems to have a little stumble or miss between 35 and 45 MPH when held at a steady speed. Get it below 35 or above 45 and it runs great. It doesn't run that bad between 35 and 45 but you can feel it hesitating.

04 Disco II w/50K