355 5.2 MAF scanner readings

Not sure what you're trying to figure out with this but it wouldn't be the cause of your current issues. One maf for both banks so if one bank is off, maf isn't it.

 

3.5L = 0.1236 ft^3. Thus 0.1236 ft^3 /2 revolutions (4 stroke engine) >> 61.8 ft^3/min at 1000 RPM >> 1.03 ft^3/sec. Mass of air at standard conditions = 0.0764 lb/ft3 >> 0.0787 lbs/sec. BUT, intake vacuum is about 1/2 atmosphere so density is about 1/2 standard conditions. >>> 0.03935 lbs/sec = 17.85 gm/sec


7 gm/sec = 0.0154lbs/sec.

 

That's quite a range.

I'm scanning a 2008 Corvette right now and it sits at 7 g/sec at 600rpm idle.

Volumetric efficiency is very low at idle but the F355 idles at a higher rpm. I would guess 5-6 g/sec but it's been years since I've scanned an F355.

 

Lets look at it another way, if your one bank fuel trims are almost perfect it really can't be high (unless you have other unlikely issues).

MAF sensor output, if an issue is almost always low. Vacuum leak, dirty sensor, sensor failing, 99% of the time will be low output and not the other way around.

 

Oops. Forgot VE factor. Somewhere between 20 and 40% at idle

VE = 40% >> 17.85 * .40 = 7.14 gm/sec

VE = 20% >> 3.57 gm/sec

 

It really can't be high if one bank fuel trim is near zero.

If maf was actually reporting abnormally high and fuel pressure is correct you would see negative fuel trims correlating by the same percentage the maf is reading high.

 

Well cold start is generally higher rpm so stands to reason airflow would be higher as well.

If one bank fuel trims are near zero and fuel pressure is correct there is no problem with maf output, at that rpm/airflow range.

 

I have a question you said you are using a generic scanner and you have 1995 car that is not OBD2 and you are comparing to a 2008 car with only 1 MAF sensor—-right so far/—

Not knowing what type of scanner it is I will say that it works on C.A.N. Which was mandated by law to start in model year 1996 and up most cars before that use different protocols for diagnostics and the scanner you are using might not work as well as it would if the system was C.A.N. And a 2008 corvette only has 1 ECM your car has 2 a master & slave that share info meaning when you hook up a diagnostic tool you are reading from the master which is then interpreting information from the slave ECM so unless you have a factory approved scanner or equivalent I would not trust anything I see out side of codes

And if you really feel that something is wrong with your engine just go old school and pull the plugs and look to see if you are running rich or lean there plenty of pics to show what you are seeing and a vacuum gauge on both banks to compare at idle they should be almost the same
this is what the ECM’s are doing through the sensors and more




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OP's car is a 5.2. One maf, one ecu, obd2

 

It's not only the size of the engine but what rpm it's running at. Can't really compare idle maf output if idle speed for one is double the other.

 

Oops I miss read the tread lol my bag


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