LT1 MAF -Technical Question

[Boostmeister]

I'd like to be able to bench test LT1 MAF's before connecting them with the translator just to weed out the duds. I apply 12 volts DC to the "C" terminal, ground to the "B" terminal. My output should be on "C". C appears to be an open-collector output, so I installed a 220k resistor from C to +3 volts. My output at C is now a negative pulse, 40 uS in width, at 288 Hz without air flow through the sensor. As I flow air through the MAF, the frequency increases. My questions are: is the C output really an open collector? What should the voltage to the pull-up resistor be, 5V, 6V, 12V?, and what should the correct resistannce for the pullup resistor be?

 

[Turbo-Fun]

 

[TurboBob]

yes

5volts

1.2 - 2K

The sensors are not calibrated for zero flow. So the frequency with no airflow will not be reliable.

Bob

 

[that national]

i was just gonna say that sounds like a question for turbo bob

 

[norbs]

I can give you a calibration curve based on g/sec vs frequency for that sensor.

 

[norbs]

This is for a stock gm camaro maf 96-97 from my abaco maf software.

 

[Boostmeister]

Thanks for all the great info! I have no reference flow in g/sec, so I'll have to be happy with a static test plus an active "hair dryer" test to see if the frequency increases. That should give me fairly good confidence whether the MAF is good or not. Plus I'll keep a log of all the ones I test for comparison purposes.

 

[norbs]

What you can do is connect a voltmeter that logs HZ and swap different maf;s to see if they are flowing different at the same rpm.

 

[Mike Licht]

This is for a stock gm camaro maf 96-97 from my abaco maf software.

That curve will be for a 3.5" LT1 sensor, the 3" is different, the LS1 is also different.
Mike

 

[norbs]

Thanks for the correction Mike, I assumed the camaro;s back then had 3" maf;s only.