My Discovery '98 was in for the second time this month to try and identify an "engine speed fluctuation " fault, and I am frustrated with the lack of initiative from my dealer to find what the precise problem is. I've now donated $600 to them and I've got nowhere!
On each visit, I've described the problem as a loss of power for EXACTLY two seconds at engine revs of 1800 - 2500 RPM. The problem is intermittent, but only happens on a warm engine (i.e., trips over 30 minutes in length). The computer reports an error code of P0300 is "misfire on multiple cylinders" (P03001 and P03007 I think they said). The response I got yesterday is the same as I got the week before: "We need to change the wires." Yesterday - they also suggested a valve job!
Wet wires (which were just wet-checked), bad plugs or sticky valves are what I would call, for the lack of a better term, 'environmental problems' which would present themselves in a sporadic or random fashion. What I'm describing is an exact 2 Second loss of power. To me, that sounds much more like it is related to the ECM.
Granted, bad wires may cause miss-fires, but not for exactly 2 seconds each and every time. Is there a safety mechanism designed in the software on the ECM that triggers when it detects an error? Does it shuts down the ignition system for two seconds to allow the revs to even out, and then restart?
I did some research in this news group last night and found that many people have had this problem. I find it difficult to believe that there is not a technical bulletin somewhere that explains this problem that so many people are having.
BTW - It's an automatic - problem persists in any gear or throttle position.
Any advice would be greatly appreciated (some have already e-mailed ideas - thanx). If there is a mechanic in southern Ontario that wants the job - pipe up.
Robert Bell