QuestionHELP !
I have a Land Rover Disc. 1997 V8 auto petrol with 204K klms which I have owned since new. Current problem, which I can't diagnose is that it irregularly (a) won't start (b), when it does start seems to run on 5 cyls (c) will start and run perfectly until under load - eg. steep hill and then miss's irregularly (d) stalls when lifting foot off the accelerator and come to a stop (e) occassionaly, when the accelerator pressed hard will choke and stutter and splutter then fire up normally again.
I pulled all the plugs out and they were covered in black carbon. I have also checked and there is spark to each plug as well.
The fuel pump sounds like it is working OK (can hear it pump when the ignition switch turned on).
My local repairer recently changed the computer box and it seems to have had little effect.
Where do I go from here ???
AnswerHi Gordon,
It could be your throttle position sensor (TPS). This is a common problem, especially with Disco I's.
It could also be in need of a valve job: another common problem to both Disco I's and II's. The exhaust valves have carbon buildup and eventually start to stick. This is best seen under load on hot, humid days, uphill and when the engine is fully warmed up. Valve job is the only known solution.
You mentioned that you had spark and noted black carbon on plugs. Could the spark be too weak? IF the spark was higher, the color would be more brown/grey.
IF your engine ignition timing was off, this too could cause this problem. Check your timing.
Best of luck,
JohnMc
