im confused vol. 1
Your long term fuel trims should be as close to 128 as you can get them and the short term should be as close to that as you can get it. Advanced mode isn't that hard with the afc do you know how to change the setting from 1 to 13 kHz? After that it'* pretty easy.
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From: springfield il

How does the maf sensor measure the airflow going inot the motor? Does it just take that number and translate it into voltage and send it back to the ecm? The article in gm high tech performance was pretty useful, but i didnt get as much from the rest of them, so do you have anymore
Aight lemme take a bash at this hehe...
It uses electricity to heat a thermistor to 212*F above air temp. Airflow cools the element and the PCM tracks how much 'effort' it takes to maintain that temperature. Thus you have a pretty accurate idea on the mass of the air. Ours are a Hitachi MAF sensor and it sends whats called a square-wave variable frequency to the PCM. This frequency ranges from 32-150hz. The PCM takes this number then factors in load, rpm, TPS, and IAT and applies the variable to a map to determine fuel delivery. The Bosch MAF sensors do the same thing, but they send a voltage between 0-5v to the PCM instead of a frequency...Make more sense?
On a side note, that is how the air/fuel calibrators work. They simply take the, say, 38hz signal and change it to 40hz for more fuel or 36hz for less. It also highlights the downside of it as you only change the MAF signal, not the other variables used in determining fuel delivery. It does the job though
It uses electricity to heat a thermistor to 212*F above air temp. Airflow cools the element and the PCM tracks how much 'effort' it takes to maintain that temperature. Thus you have a pretty accurate idea on the mass of the air. Ours are a Hitachi MAF sensor and it sends whats called a square-wave variable frequency to the PCM. This frequency ranges from 32-150hz. The PCM takes this number then factors in load, rpm, TPS, and IAT and applies the variable to a map to determine fuel delivery. The Bosch MAF sensors do the same thing, but they send a voltage between 0-5v to the PCM instead of a frequency...Make more sense?
On a side note, that is how the air/fuel calibrators work. They simply take the, say, 38hz signal and change it to 40hz for more fuel or 36hz for less. It also highlights the downside of it as you only change the MAF signal, not the other variables used in determining fuel delivery. It does the job though
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Bassplayincrowe
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Aug 21, 2003 12:56 AM



