Question about Cars & Trucks
Posted by Anonymous on
The butter fly inside the throttle body is not opening or shutting with the gas pedal. Replaced the whole throttle body assembly and GPS and the floor pedal assempby and still no luck!
Posted on Feb 05, 2013
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
You may have a problem with your MAP sensor. The Manifold Absolute Pressure (MAP) sensor signal is electrically used in a similar way to the use of Mass Air Flow (MAF) sensor signal (although internally it is built differently).
It takes a 5 volt signal from the computer, and returns a lower direct current signal in accordance with the vacuum in the engine. A higher output voltage means lower engine vacuum (which means more air flow is occurring), which is then calculated as “more fuel is needed”. Lower output signal indicates higher engine vacuum (which means lower air flow), which requires less fuel.
It's not just fuel control though. The MAP sensor signal gives the computer a dynamic indication of engine load. The computer then uses this data to control not only fuel injection, but also gear shift and cylinder ignition timing. In some cases it is even used to calculate changes in barometric pressure, to automatically adjust for different altitudes.
The Mass Air Flow (MAF) sensor helps the computer to calculate the flow and mass of the air entering the engine. It does that by measuring the cooling effect of air flow over a heated wire element. The electronic circuit inside the sensor attempts to keep the sensor at a fixed temp.
When it is cooled more by an increased air flow, more current is needed to maintain a constant temperature. The increase in current is converted into a signal to the computer. In most cars this signal would be a high frequency signal. Not as high as a radio wave, but much faster changing than the (relatively) slow frequency of the Oxygen sensor.
During low air flow rates, such as at engine idle, the MAF sensor produces a lower frequency signal. During high air flow rates, such as at wide open throttle-road load, the MAF sensor increases the frequency. The control module then converts these frequencies into their corresponding Grams-Per-Second values.
The MAP or Manifold Absolute Pressure Sensor is a little though expensive device installed in your air intake hose or piping, or installed on the firewall and connected to the manifold with a thin hose. It has 5 or 12 Volts coming in, and it simply senses the vacuum in the manifold and attenuates (reduces, weakens) this incoming voltage by a certain factor. In other words it reduces the voltage in the range of 15% to 60% of the supply voltage (depending on the car's design these numbers will vary), and this varying (but non-pulsing) signal goes to the computer. Too much attenuation kills the engine, it will simply shut off. Yet if you control it correctly you can lean down the mixture from the stoichiometric (a big word that simply means “balance of ingredients”) which is factory set at 14.7:1 (14.7 parts of air to 1 part gasoline) – down to 20:1, maybe even 50:1 or 100:1.
Good luck and hope this helps, in short: you may have a bad MAP sensor and may needs to be replaced.
Posted on Jul 07, 2009
Tips for a great answer:
Mar 20, 2014 | 2007 Ford Edge SEL
Mar 13, 2013 | 1996 Ford Crown Victoria
Aug 02, 2012 | 1999 Ford Explorer
Jan 18, 2011 | 2005 Ford Escape
Mar 27, 2010 | 2005 Ford F-150
Dec 06, 2009 | 2000 Ford Focus
Nov 22, 2009 | 1999 Volkswagen Beetle
Jul 03, 2009 | 1998 Ford Explorer
Jun 01, 2009 | 2000 Jeep Grand Cherokee
Dec 17, 2017 | Cars & Trucks
167 people viewed this question
Usually answered in minutes!