hot air problem
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hot air problem
I've solved my rough running problem which baffled all the dealer service centers in South Texas. This problem started after the 30 k service where they replaced the air intake screen per recall.
I've insulated the air intake from the hood opening to the hot wire sensor using aluminized bubble wrap and aluminum foil tape, both bought at Home Depot. This insulation keeps the duct work cooler and allows a more accurate mass flow measurement since the air temperature profile is more uniform.
The mass flow sensor is located on the outer edge of the intake tract and is presumably, in my case, measuring the hot air on the interior surface of the duct. The air temperature in the center is much lower, causing an error in mass flow measurement and a lean condition during low speed operation. Once the RPM/MAP are high enough, the heat flux from the intake duct is insignificant to the air temperature and the turbulence mixes the flow.
My installation adds a flashy look to the engine compartment, on the likes of an aircraft engine job. The real beauty is the performance.
Keith
I've insulated the air intake from the hood opening to the hot wire sensor using aluminized bubble wrap and aluminum foil tape, both bought at Home Depot. This insulation keeps the duct work cooler and allows a more accurate mass flow measurement since the air temperature profile is more uniform.
The mass flow sensor is located on the outer edge of the intake tract and is presumably, in my case, measuring the hot air on the interior surface of the duct. The air temperature in the center is much lower, causing an error in mass flow measurement and a lean condition during low speed operation. Once the RPM/MAP are high enough, the heat flux from the intake duct is insignificant to the air temperature and the turbulence mixes the flow.
My installation adds a flashy look to the engine compartment, on the likes of an aircraft engine job. The real beauty is the performance.
Keith
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