MAF size

[MrGT5oh]

Does any one know the stock MAF sensor sizes (in MM) for a 96 3.8L Mustang and a 96 4.6L Mustang.

I have upgraded my son's V6 with 19# injectors and I want to know if it is a larger size and if it is a direct fit going from 14# to 19#. Also, if it a direct replacement will it still need to be tuned? Is the sensor the same and will the 4.6L sensor connect without modification?

He is on a budget and prefer not to pay more for a new aftermarket sensor.

Thanks in advance for you technical assistance.

[jdgregory84]

Don't take this for fact but I think it's like 67mm or something really close to that. Are you looking for the physical size, or what the processor reads to determine the air/fuel ratio?

[MrGT5oh]

Don't take this for fact but I think it's like 67mm or something really close to that. Are you looking for the physical size, or what the processor reads to determine the air/fuel ratio?

I'm wondering if the GT MAF is bigger and if it will work with the computer/wiring harness without modification and work with the 19lb injectors that I switched to (as well as other modifications).

[STRONGNUFF]

I'm pretty sure that the 96 4.6 gt is an 80mm MAF

[STRONGNUFF]

And the 96 3.8l was a 70mm

[MrGT5oh]

And the 96 3.8l was a 70mm

Thanks for the info.

[johnboy]

I know this isn't about the MAF, but on my 98 V6 I have a 94-95 5.0 throttlebody that is modified to fit. Its a little bigger then the BBK aftermarket and fairly simple to modify. Let me know if you want more info about this.

[TENGRAM]

I'm wondering if the GT MAF is bigger and if it will work with the computer/wiring harness without modification and work with the 19lb injectors that I switched to (as well as other modifications).

The injector size is accounted for in the ECM program not in the MAF sensor. You may get lucky and be close with a different MAF (which could have a completely different response than the stock MAF sensor) or it may be much further off even than the one you have now, but it most certainly will not be optimum.

[MrGT5oh]

The injector size is accounted for in the ECM program not in the MAF sensor. You may get lucky and be close with a different MAF (which could have a completely different response than the stock MAF sensor) or it may be much further off even than the one you have now, but it most certainly will not be optimum.

it was my understanding that the sampling tube was matched to the injectors. is that not correct?

We plan on getting a tune, but i want to keep it from running rich until we get it.

[TENGRAM]

it was my understanding that the sampling tube was matched to the injectors. is that not correct?

We plan on getting a tune, but i want to keep it from running rich until we get it.

C&L meters use sample tubes to fool the computer into thinking that less air is flowing through the meter than actually is. The ECM "sees" less air and decreases the amount of time the injectors are open, effectively compensating for larger injectors.

In a nutshell, for any given amount of airflow the MAF sensor returns a voltage from 0 to 5 volts representing the amount of air. Different MAF sensors have different responses (mainly in scale) to the air flow. The ECM has a table from which it correlates the amount of airflow to the sensor voltage received. Separately, the ECM has a value (actually two values, but I digress...) representing the injector flow capability. By tuning you can adjust this value directly to account for the larger injectors.

Aftermarket MAFs all work from a similar principle as the C&L. Whether the response of the sensor itself is skewed or the effect of the air flow is, they work to fool the computer into thinking that less airflow is coming through than actually is.

For a small change in injector size the aftermarket method typically works fine.

[duchtr]

This is a topic I have spent the last moth or so researching, but for a GT. First thing first, you have to understand how the EEC-V computer is going to respond to a different MAF. It has been mentioned in this thread, but I will restate it for posting's sake.

AT WOT (wide open throttle)
The computer simply sees a voltage from the MAF, IAT (intake air temp) and without a tune, opens the injector for the amount specified by the computer. Since you added about 25% more fuel, you are going to run 25% richer at WOT. You need! NEED! to get on a dyno, or have a wide-band 02 gauge in the car to know if the car is running rich or lean. If you are running FAT now, than there are a few ways to fix this issue. One would be to send less voltage to the computer, by building an inline circuit to split/reduce voltage, and lean the car back out. The other is an aftermarket MAF that is "calibrated to your needs." If you run the GT MAF, make sure you know what the voltage differences are, and then use a ton of Math to guess your way to correct.

At part throttle, the 02 sensors will tell the computer what A/F ratio you have and adjust accordingly.

GL!!!