MAF
02-11-2012, 09:19 AM
#11
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Found this short but interesting article, so if the OP would point to us all where they're talking about the tranny:
Hot wire sensor (MAF)
A hot wire mass airflow sensor determines the mass of air flowing into the engine's air intake system. The theory of operation of the hot wire mass airflow sensor is similar to that of the hot wire anemometer (which determines air velocity). The General Motors division (GM) was the first car company to use the hot wire sensor.[citation needed] This is achieved by heating a wire with an electric current that is suspended in the engine's air stream, like a toaster wire. The wire's electrical resistance increases as the wire's temperature increases, which limits electrical current flowing through the circuit. When air flows past the wire, the wire cools, decreasing its resistance, which in turn allows more current to flow through the circuit. As more current flows, the wire's temperature increases until the resistance reaches equilibrium again. The amount of current required to maintain the wire's temperature is directly proportional to the mass of air flowing past the wire. The integrated electronic circuit converts the measurement of current into a voltage signal which is sent to the ECU.
If air density increases due to pressure increase or temperature drop, but the air volume remains constant, the denser air will remove more heat from the wire indicating a higher mass airflow. Unlike the vane meter's paddle sensing element, the hot wire responds directly to air density. This sensor's capabilities are well suited to support the gasoline combustion process which fundamentally responds to air mass, not air volume. (See stoichiometry.)
This sensor sometimes employs a mixture screw, but this screw is fully electronic and uses a variable resistor (potentiometer) instead of an air bypass screw. The screw needs more turns to achieve the desired results. A hot wire burn-off cleaning circuit is employed on some of these sensors. A burn-off relay applies a high current through the platinum hot wire after the vehicle is turned off for a second or so, thereby burning or vaporizing any contaminants that have stuck to the platinum hot wire element.
The hot film MAF sensor works somewhat similar to the hot wire MAF sensor, but instead it usually outputs a frequency signal. This sensor uses a hot film-grid instead of a hot wire. It is commonly found in late 80's early 90's fuel-injected vehicles. The output frequency is directly proportional to the amount of air entering the engine. So as air flow increases so does frequency. These sensors tend to cause intermittent problems due to internal electrical failures. The use of an oscilloscope is strongly recommended to check the output frequency of these sensors. Frequency distortion is also common when the sensor starts to fail. Many technicians in the field use a tap test with very conclusive results. Not all HFM systems output a frequency. In some cases, this sensor works by outputting a regular varying voltage signal.
Some of the benefits of a hot-wire MAF compared to the older style vane meter are:
-responds very quickly to changes in air flow
-low airflow restriction
-smaller overall package
-less sensitive to mounting location and orientation
-no moving parts improve its durability
-less expensive
-separate temperature and pressure
-sensors are not required (to determine air mass)
There are some drawbacks:
-dirt and oil can contaminate the hot-wire deteriorating its accuracy
-installation requires a laminar flow across the hot-wire
Hot wire sensor (MAF)
A hot wire mass airflow sensor determines the mass of air flowing into the engine's air intake system. The theory of operation of the hot wire mass airflow sensor is similar to that of the hot wire anemometer (which determines air velocity). The General Motors division (GM) was the first car company to use the hot wire sensor.[citation needed] This is achieved by heating a wire with an electric current that is suspended in the engine's air stream, like a toaster wire. The wire's electrical resistance increases as the wire's temperature increases, which limits electrical current flowing through the circuit. When air flows past the wire, the wire cools, decreasing its resistance, which in turn allows more current to flow through the circuit. As more current flows, the wire's temperature increases until the resistance reaches equilibrium again. The amount of current required to maintain the wire's temperature is directly proportional to the mass of air flowing past the wire. The integrated electronic circuit converts the measurement of current into a voltage signal which is sent to the ECU.
If air density increases due to pressure increase or temperature drop, but the air volume remains constant, the denser air will remove more heat from the wire indicating a higher mass airflow. Unlike the vane meter's paddle sensing element, the hot wire responds directly to air density. This sensor's capabilities are well suited to support the gasoline combustion process which fundamentally responds to air mass, not air volume. (See stoichiometry.)
This sensor sometimes employs a mixture screw, but this screw is fully electronic and uses a variable resistor (potentiometer) instead of an air bypass screw. The screw needs more turns to achieve the desired results. A hot wire burn-off cleaning circuit is employed on some of these sensors. A burn-off relay applies a high current through the platinum hot wire after the vehicle is turned off for a second or so, thereby burning or vaporizing any contaminants that have stuck to the platinum hot wire element.
The hot film MAF sensor works somewhat similar to the hot wire MAF sensor, but instead it usually outputs a frequency signal. This sensor uses a hot film-grid instead of a hot wire. It is commonly found in late 80's early 90's fuel-injected vehicles. The output frequency is directly proportional to the amount of air entering the engine. So as air flow increases so does frequency. These sensors tend to cause intermittent problems due to internal electrical failures. The use of an oscilloscope is strongly recommended to check the output frequency of these sensors. Frequency distortion is also common when the sensor starts to fail. Many technicians in the field use a tap test with very conclusive results. Not all HFM systems output a frequency. In some cases, this sensor works by outputting a regular varying voltage signal.
Some of the benefits of a hot-wire MAF compared to the older style vane meter are:
-responds very quickly to changes in air flow
-low airflow restriction
-smaller overall package
-less sensitive to mounting location and orientation
-no moving parts improve its durability
-less expensive
-separate temperature and pressure
-sensors are not required (to determine air mass)
There are some drawbacks:
-dirt and oil can contaminate the hot-wire deteriorating its accuracy
-installation requires a laminar flow across the hot-wire
02-11-2012, 10:41 PM
#12
Also 2004 used a 6 wire MAF/IAT to measure Air Flow + Temperature, so the puter can really dig it.
02-12-2012, 11:30 PM
#13
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rebuild inb progress
Sorry man, but everybody is right. The MAF has absolutely no bearing on trans performance. The transmission only transfers torque from the engine to the wheels. Plain and simple. The MAF sensor would, however, greatly influence engine performance. A lot of people do mistake engine power problems for transmission problems. Not saying you don't have one, just take a look at engine performance before you condemn the tranny. On the other hand, just take it back to the shop that did the rebuild and voice your concerns. Nobody's perfect, so they could have botched a seal somewhere in there.
It's on it's 3rd torque converter, and it's been apart twice by one mechanic, it now being rebuilt by a trans shop....fk this...been out if my truck for over a month.
Thanks for the post.
02-12-2012, 11:35 PM
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Found this short but interesting article, so if the OP would point to us all where they're talking about the tranny:
Hot wire sensor (MAF)
A hot wire mass airflow sensor determines the mass of air flowing into the engine's air intake system. The theory of operation of the hot wire mass airflow sensor is similar to that of the hot wire anemometer (which determines air velocity). The General Motors division (GM) was the first car company to use the hot wire sensor.[citation needed] This is achieved by heating a wire with an electric current that is suspended in the engine's air stream, like a toaster wire. The wire's electrical resistance increases as the wire's temperature increases, which limits electrical current flowing through the circuit. When air flows past the wire, the wire cools, decreasing its resistance, which in turn allows more current to flow through the circuit. As more current flows, the wire's temperature increases until the resistance reaches equilibrium again. The amount of current required to maintain the wire's temperature is directly proportional to the mass of air flowing past the wire. The integrated electronic circuit converts the measurement of current into a voltage signal which is sent to the ECU.
If air density increases due to pressure increase or temperature drop, but the air volume remains constant, the denser air will remove more heat from the wire indicating a higher mass airflow. Unlike the vane meter's paddle sensing element, the hot wire responds directly to air density. This sensor's capabilities are well suited to support the gasoline combustion process which fundamentally responds to air mass, not air volume. (See stoichiometry.)
This sensor sometimes employs a mixture screw, but this screw is fully electronic and uses a variable resistor (potentiometer) instead of an air bypass screw. The screw needs more turns to achieve the desired results. A hot wire burn-off cleaning circuit is employed on some of these sensors. A burn-off relay applies a high current through the platinum hot wire after the vehicle is turned off for a second or so, thereby burning or vaporizing any contaminants that have stuck to the platinum hot wire element.
The hot film MAF sensor works somewhat similar to the hot wire MAF sensor, but instead it usually outputs a frequency signal. This sensor uses a hot film-grid instead of a hot wire. It is commonly found in late 80's early 90's fuel-injected vehicles. The output frequency is directly proportional to the amount of air entering the engine. So as air flow increases so does frequency. These sensors tend to cause intermittent problems due to internal electrical failures. The use of an oscilloscope is strongly recommended to check the output frequency of these sensors. Frequency distortion is also common when the sensor starts to fail. Many technicians in the field use a tap test with very conclusive results. Not all HFM systems output a frequency. In some cases, this sensor works by outputting a regular varying voltage signal.
Some of the benefits of a hot-wire MAF compared to the older style vane meter are:
-responds very quickly to changes in air flow
-low airflow restriction
-smaller overall package
-less sensitive to mounting location and orientation
-no moving parts improve its durability
-less expensive
-separate temperature and pressure
-sensors are not required (to determine air mass)
There are some drawbacks:
-dirt and oil can contaminate the hot-wire deteriorating its accuracy
-installation requires a laminar flow across the hot-wire
Hot wire sensor (MAF)
A hot wire mass airflow sensor determines the mass of air flowing into the engine's air intake system. The theory of operation of the hot wire mass airflow sensor is similar to that of the hot wire anemometer (which determines air velocity). The General Motors division (GM) was the first car company to use the hot wire sensor.[citation needed] This is achieved by heating a wire with an electric current that is suspended in the engine's air stream, like a toaster wire. The wire's electrical resistance increases as the wire's temperature increases, which limits electrical current flowing through the circuit. When air flows past the wire, the wire cools, decreasing its resistance, which in turn allows more current to flow through the circuit. As more current flows, the wire's temperature increases until the resistance reaches equilibrium again. The amount of current required to maintain the wire's temperature is directly proportional to the mass of air flowing past the wire. The integrated electronic circuit converts the measurement of current into a voltage signal which is sent to the ECU.
If air density increases due to pressure increase or temperature drop, but the air volume remains constant, the denser air will remove more heat from the wire indicating a higher mass airflow. Unlike the vane meter's paddle sensing element, the hot wire responds directly to air density. This sensor's capabilities are well suited to support the gasoline combustion process which fundamentally responds to air mass, not air volume. (See stoichiometry.)
This sensor sometimes employs a mixture screw, but this screw is fully electronic and uses a variable resistor (potentiometer) instead of an air bypass screw. The screw needs more turns to achieve the desired results. A hot wire burn-off cleaning circuit is employed on some of these sensors. A burn-off relay applies a high current through the platinum hot wire after the vehicle is turned off for a second or so, thereby burning or vaporizing any contaminants that have stuck to the platinum hot wire element.
The hot film MAF sensor works somewhat similar to the hot wire MAF sensor, but instead it usually outputs a frequency signal. This sensor uses a hot film-grid instead of a hot wire. It is commonly found in late 80's early 90's fuel-injected vehicles. The output frequency is directly proportional to the amount of air entering the engine. So as air flow increases so does frequency. These sensors tend to cause intermittent problems due to internal electrical failures. The use of an oscilloscope is strongly recommended to check the output frequency of these sensors. Frequency distortion is also common when the sensor starts to fail. Many technicians in the field use a tap test with very conclusive results. Not all HFM systems output a frequency. In some cases, this sensor works by outputting a regular varying voltage signal.
Some of the benefits of a hot-wire MAF compared to the older style vane meter are:
-responds very quickly to changes in air flow
-low airflow restriction
-smaller overall package
-less sensitive to mounting location and orientation
-no moving parts improve its durability
-less expensive
-separate temperature and pressure
-sensors are not required (to determine air mass)
There are some drawbacks:
-dirt and oil can contaminate the hot-wire deteriorating its accuracy
-installation requires a laminar flow across the hot-wire
02-12-2012, 11:40 PM
#15
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cool
I already bought a brand spankin new maf, but thanks for ur professional opinion ACE!
02-13-2012, 12:39 AM
#16
If you plug in a good quality code reader, you can navigate it to real time and start the motor. Then you can navigate to the Maf and click on it and bring up the graph and watch what a maf does. It changes the voltage thru it from .5 volts to upwards of 10 volts as the air is pulled by it due to the vacuum produced by the pistons going down with the intake valves open. The CPU uses the voltage to adjust the amount of fuel/time the injector is open. Unplug it and the engine quits running. There are anywhere from 12 to 18 wires that run out of the same CPU that run to the transmission. They also run to the VSS and to the Cruise. Wires run to the Throttle Body from the CPU, every eletrocal devise on the truck practically is controlled by the CPU. In conclusion the Battery supplies the Voltage to the CPU and it runs everything so to speak. When you slam the pedal to the metal you run the CPU and it runs you. I hope this is most helpful, LOL.
Last edited by papa tiger; 02-13-2012 at 12:43 AM.
02-13-2012, 12:52 AM
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But what's the point of asking the question if you already bought a brand spankin new maf? That should have fixed your transmissions problems already... Right?
And don't take it so hard if some people just want to help you here...!
Last edited by outbacktaz; 02-13-2012 at 02:18 AM.
02-13-2012, 01:04 AM
#18
I think everyone need to sit down.. And take a chill pill.. No name calling... Or trolling..
With that said... I think anything can effect the way the transmission shifts... If your engine is not running correctly its going to be a little akward... I sorta agree with everyone... It has no actual ties to the trans... Its the same thing as saying does a fouled spark plug affect the transmission.... No it doesn't but it does make it shift funky because the engine is not running its 100 percent ....Then again this is all my opinion.... No need to get pissy with errrrone
PS.... Respect other members.
With that said... I think anything can effect the way the transmission shifts... If your engine is not running correctly its going to be a little akward... I sorta agree with everyone... It has no actual ties to the trans... Its the same thing as saying does a fouled spark plug affect the transmission.... No it doesn't but it does make it shift funky because the engine is not running its 100 percent ....Then again this is all my opinion.... No need to get pissy with errrrone
PS.... Respect other members.
02-13-2012, 10:03 AM
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I think everyone need to sit down.. And take a chill pill.. No name calling... Or trolling..
With that said... I think anything can effect the way the transmission shifts... If your engine is not running correctly its going to be a little akward... I sorta agree with everyone... It has no actual ties to the trans... Its the same thing as saying does a fouled spark plug affect the transmission.... No it doesn't but it does make it shift funky because the engine is not running its 100 percent ....Then again this is all my opinion.... No need to get pissy with errrrone
PS.... Respect other members.
With that said... I think anything can effect the way the transmission shifts... If your engine is not running correctly its going to be a little akward... I sorta agree with everyone... It has no actual ties to the trans... Its the same thing as saying does a fouled spark plug affect the transmission.... No it doesn't but it does make it shift funky because the engine is not running its 100 percent ....Then again this is all my opinion.... No need to get pissy with errrrone
PS.... Respect other members.