2000 RR 4.6 flatspot/misfire on kickdown and hills

Over the last 4 months my 2000 Vogue has developed a worrying tendency to misfire at around 3000rpm both on hills and on kickdown with the engine also refusing to increase revs at all depsite increasing throttle input. The problem lasts for around 30 seconds and is intermittent. Backing off on the throttle sometimes helps. This problem is now getting dangerous as overtaking has become a little risky. Could it be something to do with MAF as i also have rough idling intermittently at around 500-550 RPM which is eually annoying as it ruins the normally outstanding ride comfort and is disconcerting at traffic lights.

Thoughts on a postcard please...

I had a similar sounding problem a few years back, turned out to be a new set of HT leads required, and problem solved

The standard leads are total rubbish. Get some magnacore leads which will see the car to the grave £90 but well worth it. I think island 4x4 do a similar set for £30 but cannot comment on quality. Could be maf or you have an air leak downstream of the maf. Check the idle control valve

Willos said:

island 4x4 do a similar set for £30 but cannot comment on quality.

Click to expand...

hmm. worth a new thread, that.