QuestionHello, John-
I have a 96 disco w/ 175,000 miles, it was re-engined at 90,000 miles when I experienced cylinder liner drop. On 200 mile trip, I started experiencing loss of power and what felt like a misfire. When I got back home, I read a Cylinder #3 misfire code.
I can start normally. I'm not certain if the misfire becomes more prevalent once warmed up; I haven't gotten out and tried to step on the accelerator when it's cold. I occasionally get a check-engine light that codes out to one bank running rich. I replaced all O2 sensors about 15,000 miles ago, but didn't replace the cat after the first engine blew. I haven't replaced wires or plugs since the re-engine.
I've seenother people advise a stuck valve and suggest using Marvel Mystery Oil for a couple of hundre miles. I've seen some advice from you to someone with a similar problem, suggsesting the Spark amplifier module problem.
Somewhat fortunately, I bought another '96 Disco with a blown engine, since it seemd to have been reasonable well cared for and would be a great source of parts - so I might be able to do some parts swap-outs to help diagnose.
Any suggestions would be greatly apreciated. Thanks
Greg G.
AnswerHi Greg,
firstly, I'd replace the plugs and wires to be sure its not as simple as that. Its a low-cost fix that could make a difference.
SAM would give you difficult cold starts. Sounds more likely air mix and it could be your MAF. The MAF can fail anytime, cause misfires and it would affect your performance. Try swapping the MAF - you are in a unique position to test this out. Nice.
Stuck exhaust valve(s) would give you poor performance (lack of power) and you'd be able to notice this on steep hill climbs, hot and humid days and when towing. Valve job is the only fix for exhaust valve sticking (about $2500).
I hope its only a faulty plug or wire.
Best of luck,
JohnMc
