Disassembled MAF sensor..anyone have specs?

[wade]

Since I have two MAF sensors, I decided to take one apart. I drilled the rivets out and it slides right out. I have it a much better cleaning with CRC Mass Air Flow Sensor cleaner and I've reassembled it and am back on the road. I used small screws instead of the rivets to put it back together. The interesting part is that inside there appears to be a calibration screw...a small white plastic one with a slot for a flat head screw driver. I'd like to recalibrate it since over time I'm sure metals with heating and cooling change resistivity. Does anyone have the specs on what the output voltage should be. I thought I read 1.8 V somewhere, but I can't find it. Thanks for any help.

[Disco Mike]

Good question Wade, I don't think I have seen any one else approach recalibration on an old MAF.
Be curious to see what you find.
Mike

[O.B.]

Gleened these from a Bosch MAF, don't know how valid they are for D1s:

rpm volts
700 1.8 (idle)
1000 2.2
1500 2.5
2000 2.8
2500 3.1
3000 3.4
3500 3.9
4000 4.0
4500 4.1
5000 4.2 (max)

[Disco Mike]

They do not pretain to the D1's, good old Lucas stuff.
Mike

[wade]

Thanks for the replies. Since I have another, I may run some test voltages in case I get it really out of whack, and then try to adjust it just a little. Hopefully I can get rid of just a little bit of roughness. I'm at about 14 mpg with the A/C on all the time, so it isn't bad for in town driving (for a LR), but it would be nice if it felt a little smoother.

[wade]

With a digital multimeter, I've checked the signal voltages on both of my MAF sensors and surprisingly, both read the same. There are three wires running to the MAF sensor. The Red with a black trace is the ground; the blue with the green trace is the signal, and the brown with the orange trace is the power 12V. I found the number 1.8 on RPI engineering's website as being the best voltage for the lowest CO value at idle, but I think it was for their modified system. I've sent them an email requesting information which I'll post later if I get it. I, by the way, used the sharp leads on the multimeter and pushed them through the plastic on the wires to the MAF sensors to take the readings (as opposed to trying to take the cover off the connector). I'll cover with electrical tape when I'm through.

Here are the numbers:

740 rpm (idle) 1.36 V
1000 rpm 1.41V
1500 rpm 1.61 V
2000 rpm 1.77 V
(The other MAF sensor was at 1.31, 1.36, 1.62, 1.77) This was with my wife trying to hold the tach on the correct rpms, so my conclusion is they are putting the same signal out.

I still need to test the input power voltage. After I had decided the MAF sensors probably are both good (the chances of both being bad and having the same voltage output is slim...don't you think?), I pulled the Idle air control valve and it is literally caked with carbon. I sprayed some choke cleaner on it, but it didn't put a dent in the carbon. Anyone have a suggestion on the best way to clean it?

I suppose I could adjust one of the MAF sensors to 1.8 at idle and see if it will run, but I think I'll wait until I'm sure what the voltages should be.