Quick6
New Member
- Posts
- 1
- Location
- New Zealand
Hello from New Zealand. I was hoping to get an answer for this one a little closer to home but no luck so far. Searched plenty, found a couple of posts with similar symptoms but no outcomes. Any input appreciated!
The vehicle is a 2000 Discovery 2 V8 manual, 255000km on the clock, engine rebuilt around 70000km ago, well maintained, plugs and leads done recently and I have put in a new MAF. Very quiet and smooth engine. No CEL and no codes at all.
The problem I have is a large hesitation/flat spot under strong acceleration, doesn't appear to be a miss. Does not do it until it is at operating temperature. If you change down a gear and give it a boot full it just falls flat on its face, if you change down and pause or ease into it it often accelerates cleanly. As mentioned I replaced the MAF as it seemed a likely culprit, slight improvement. In my diagnostic journey I have found that it never appears to enter 'closed loop' fuelling. The o2 sensors (only have upstream pair on this model as it is NZ new) are pegged at 1.125v even with the engine off, all fuel trims are at 0 and don't change. Engine warms up as expected and maintains 85-95 degrees c. The idle varies a little and sometimes gets quite 'lumpy'. Smells very rich. Interestingly still returns what I would consider reasonable economy (for one of these!) on a trip, around 600km/tank. Premium fuel 96-98 octane. It looks like it may be 'pulling timing' when it happens?
Any ideas? Thanks in advance.....
The vehicle is a 2000 Discovery 2 V8 manual, 255000km on the clock, engine rebuilt around 70000km ago, well maintained, plugs and leads done recently and I have put in a new MAF. Very quiet and smooth engine. No CEL and no codes at all.
The problem I have is a large hesitation/flat spot under strong acceleration, doesn't appear to be a miss. Does not do it until it is at operating temperature. If you change down a gear and give it a boot full it just falls flat on its face, if you change down and pause or ease into it it often accelerates cleanly. As mentioned I replaced the MAF as it seemed a likely culprit, slight improvement. In my diagnostic journey I have found that it never appears to enter 'closed loop' fuelling. The o2 sensors (only have upstream pair on this model as it is NZ new) are pegged at 1.125v even with the engine off, all fuel trims are at 0 and don't change. Engine warms up as expected and maintains 85-95 degrees c. The idle varies a little and sometimes gets quite 'lumpy'. Smells very rich. Interestingly still returns what I would consider reasonable economy (for one of these!) on a trip, around 600km/tank. Premium fuel 96-98 octane. It looks like it may be 'pulling timing' when it happens?
Any ideas? Thanks in advance.....
