Running Lean - Dynograph attached

[AutoSHO]

The difference between a MAF giving the computer a signal to run 14:1 and 12.5:1 is not a big enough difference that simply backprobing the sensor is going to show a problem.

The Mass Air Flow sensor measures air mass (hence the name) which means that air density has an effect on the sensor's output - This is what makes it better than a speed density (MAP) system. It can account for the changing air density at differing elevations, temperatures, etc.

The SHO would run very poorly or not at all if the MAF signal was way out of whack - Thats why I said it is pointless to backprobe it. The minute differences involved are not enough that simply stating it should be around 4v at WOT/7000 rpm will provide any real results for Dale. I had a MAF that was extremely bad, and it was still producing very close to 4v at WOT at 7000 rpm... but the car was running extremely lean... and I live at 5k feet myself.

 

[SHOKYLE1]

it also measures the flow or quantity (volume). hence the name mass air FLOW. and a sensor out of range will not always run poorly. but it will effect the f/a ratio when you go to wot. your vehicle computer will adujst the long term fuel trim lean if the sensor is under estimating the air flow at idle or low load in closed loop when you go into open loop at wot the long term fuel trim will be applied will cause a lean comdition. and his huge spike to 16.3 to one can be cause by a drop out of the sensor and you could see this by back probing the sensor. by the way what were the voltage at 2000rpm 3000rpm 4000rpm .... fairly smooth raise in voltage or slow raise then jump to 4v. or around .5 at idle drop outs rises then 4v. you cant just say it went all the way up to four so it tested good but it was really bad. got to look at entire range for any problems. i'm sure you know this though and are trying to make me look like a a$$

 

[Rockledge]

yes. the sensor just mesures the amount of voltage it takes to keep the hot wire 200 degrees above the temperature of the reference wire.

To elaborate just a little, the MAF sensor keeps one filamant, the so-called "hot wire", 200*Celsius above the "cold" wire (cold wire = temp. of incoming 'ambient' air) which means the hot wire can get pretty darn hot.

That's one reason why the MAF sensor can fail, because of this extremely hot filiament being bombarded over a period of time by foreign material (such as oil).

Technically speaking, the MAF measures air mass, and not volume.

And it's also interesting to note that the SHO engine managment system employs a BARO sensor, while virtually no other Ford setup with an MAF does so (3.8L SC is the only other one I know of).

 

[DHMag]

O'Rielly's will try to sell you a plastic ECT.

Wells SU201... just go to auto-zone...

i refuse to shop at Auto-Zone.

 

[SHOtimer]

brass contacts with a plastic connector...thats how all of them are made.

Correct the part emerged in coolant is brass in all of them. But, in the non-motorcraft versions the portion of the sensor that has the hex on it for a wrench is plastic and has as tendency to break. But, the motorcraft one is made with brass all the way up to the connector.

Doug

 

[DHMag]

Correct the part emerged in coolant is brass in all of them. But, in the non-motorcraft versions the portion of the sensor that has the hex on it for a wrench is plastic and has as tendency to break. But, the motorcraft one is made with brass all the way up to the connector.

Doug

i know for sure the Auto-Zone Wells brand has a brass hex with a plastic connector set in an epoxy.

 

[SHOtimer]

Well, I must be mistaken. I thought for sure the time I got a plastic one was AZ.

Doug