troverman
Member Since: 09 Sep 2008
Location: New Hampshire
Posts: 51
  
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I have a 2005 LR3 V8 SE with 100k miles on it. The engine starts normally, but then settles into an oscillating idle, with revs ranging from normal (~800 RPM) to low (~300-400 RPM). Having the climate control on makes the problem worse because the A/C compressor kicks on. This is a constant engine speed oscillation problem, occasionally with the revs dropping so low the vehicle stalls. Under acceleration, the engine runs fine. Fuel economy is poor. I have scanned with the Hawkeye tool and found no DTC's; the MIL is off.
However, viewing live engine data on the Hawkeye reveals the "External Air Temp" is -11C and yet the "Ambient Air Temp" is 17C. The actual air temp is, in fact, 17C; the "External Air Temp" never budged off from -11C either.
Where is this sensor? Is it part of the MAF? Does it measure intake air temp? I suspect this could be overfuelling at the very least and causing the poor fuel economy.
I also noticed the "Calculated Load" at idle, in Park, was fluctuating between 30-44%. The upstream O2 sensors were both at 0mA; the downstream sensors registered 0.58V and 0.78V. There was a big difference between cylinder banks for "LTFT," whatever that parameter is.
Based on this info, does anyone have a suggestion as to what the problem is? Possibly the MAF? Recent maintenance includes spark plugs (OEM) and air filter (OEM). Current Rovers:
2005 LR3 V8 SE
1992 Range Rover County
1997 Range Rover 4.0SE
Previous Rovers:
2000 Discovery II SD
1995 Range Rover 4.0SE
1992 Range Rover County
Also Current:
2012 Volkswagen GTI 2.0 TSI
1995 Mercedes-Benz E320
1999 Audi A8 4.2 quattro
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 9th Mar 2012 3:31 pm |
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