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Discussion Starter · #1 ·
what's a mass air flow sensor and how does it work? and dont say it measures the mass of air..even if that is what it does tell me why it's important and how it works..
 

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Measures air intake flow, and while mostly used on gas engines, it was used on S vin code 6.5's for a few years. The computer needs it to carry out certian tasks... I'm pretty sure it's for emissions sake on the 6.5.

"A mass airflow sensor is used to determine the mass of air entering an electronically fuel-injected engine. The air mass information is necessary for the engine control unit to calculate and deliver the correct fuel mass to the engine. Air changes its density as it expands and contracts with temperature and pressure. In automotive applications, air density varies with the vehicle's operating environment, and this is an ideal application for a mass sensor."

http://en.wikipedia.org/wiki/Mass_flow_sensor
 

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I know that Ford ones work by using two wires in them. One of them just measures ambient temperature and the other one is heated really hot. The incomming air cools the heated wire and the computer makes a calculation on how much air is comming in by comparing the temperatures of the wires.
 

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I know that Ford ones work by using two wires in them. One of them just measures ambient temperature and the other one is heated really hot. The incomming air cools the heated wire and the computer makes a calculation on how much air is comming in by comparing the temperatures of the wires.
Kinda.

A cold wire pulls alot of current to start heating up. The hotter it gets, the higher the resistance is. Example - Cold is .02 ohm, hot wire is 2.6 ohm. When you blow air past the hot wire, it tries to cool it, and the reistance goes down. Quit blowing air past it, and the resistance climbs back up.

My measuring the resitance of the hot wire vs the cold wire, you can determine the mass of air going through the sensor. You don't measure the temp of the wires, but the resistance (Usually through current draw).
 

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what's a mass air flow sensor and how does it work? and dont say it measures the mass of air..even if that is what it does tell me why it's important and how it works..
If the question is sort of hypothetical, that's fine.

But, you must understand that you don't have one, on your truck.
 

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Since I have one what would happen if I remove it? Any performance gains? I'm sure some codes will be set...:(
 

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Mass air flow sensors simply measures how much air is going into the engine, then the ECM takes this number and calculates how much fuel to inject to maintain the correct air/fule ratio. Mass air flow sensing sytems work very well on engines with larger camshafts, or low manifold vacuum. The other style of measuring air flow is a MAP sensing system. By measuring the manifold vacuum versus throttle position and engine RPM the ECM can calculate how much air is going to the engine and how much fuel to give it. The downfall to MAP systems is they MUST have good manifold vacuum at idle in order to properly function, otherwise you have to program to fuel the engine based soley off of throttle position and RPM. This is how the info is udes in a gas application.

In a diesel it is still used to measure incoming airflow. They used it on the 96+ S engines so the PCM would know how much the EGR was recirculating into the engine. And I believe it also worked in conjunction with the fueling to keep smoke to a minumum before the boost comes up. I believe they use it on the DMAX to reduce smoke as well.

If you have an S engine and want to do away with the MAF sensor. The easiest way is to go with an F PCM.
 

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Yeah, you don't wanna just yank it off. Bad things happen - codes set, runs like crap, a micro-sized version of your dead grandmother climbs up your leg with a knife between her teeth, etc.

Leave it there. It only does good anyhow.
 

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Discussion Starter · #9 ·
well the reason i ask is that i was lookin at buying a cold air intake on ebay and it said it doesnt include a mass air flow sensor..
 

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Well, that is what you would want then, because you have an F vin truck (HD) which means you don't have one and the mass air flow sensor is for the s vin trucks (LD)
 

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Discussion Starter · #11 ·
if i dont already have one why would i need one if i bought a new one?
 

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Doesn't mean everything on Ebay is right. They sold a piece of toast that was posessed with the spirit of Elvis for god sakes.
 

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Discussion Starter · #15 ·
probably option 2...you stepped into the twilight zone
 

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well the reason i ask is that i was lookin at buying a cold air intake on ebay and it said it doesnt include a mass air flow sensor..
Meaning it doesn't have one, but it's built to take one, or it isn't built to take one? F code engines don't need/have a mass airflow sensor, so you'd want an intake built for an F code engine.
 

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Nor do most S engine trucks 97+ was MAF equipped introduction, & I think only up to 1999 had them, only way to run in bypass is with reflash S to F or swap to a stock F PCM
 
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