94-95 & 96-97 MAF Delete Discussion - Page 4 - Miata Turbo Forum - Boost cars, acquire cats.

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Old 11-21-2007, 11:53 PM   #61
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BECAUSE IVE TOLD YOU TIME AND TIME AND TIME AND TIME AND TIME AGAIN THE SIGNAL IS 5-0v!!!!!!!!!!!!!!!!!!

THATS FIVE TO ZERO.


WHEN IT'S THE HIGHEST TEMP ITS 5 VOLTS. WHEN AIR PASSES OVER THE SENSOR THE RESISTANCE INCREASES AND THE VOLTAGE DROPS TO 0 AT ITS COLDEST!!!!!!!!!!!!!!!

HELL, IF YOU'D CLICK THE LINK I GAVE YOU, YOU CAN SEE THE GOD DAMN SIGNAL ON A OSCILLOSCOPE!


HENSE MY MOTHERFUCKING INSISTANCE ON TRYING TO TRICK THE ECU INTO SEEING 5 ******* VOLTS AT THE MAF SIGNAL INPUT.


JESUS HOLY COW.
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Old 11-22-2007, 12:38 AM   #62
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Well since you put it that way.

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Old 11-23-2007, 01:33 AM   #63
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Quote:
Originally Posted by Braineack View Post
BECAUSE IVE TOLD YOU TIME AND TIME AND TIME AND TIME AND TIME AGAIN THE SIGNAL IS 5-0v!!!!!!!!!!!!!!!!!!

THATS FIVE TO ZERO.


WHEN IT'S THE HIGHEST TEMP ITS 5 VOLTS. WHEN AIR PASSES OVER THE SENSOR THE RESISTANCE INCREASES AND THE VOLTAGE DROPS TO 0 AT ITS COLDEST!!!!!!!!!!!!!!!

HELL, IF YOU'D CLICK THE LINK I GAVE YOU, YOU CAN SEE THE GOD DAMN SIGNAL ON A OSCILLOSCOPE!


HENSE MY MOTHERFUCKING INSISTANCE ON TRYING TO TRICK THE ECU INTO SEEING 5 ******* VOLTS AT THE MAF SIGNAL INPUT.


JESUS HOLY COW.

Thought I'd quote that to emphasize your point
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Old 12-22-2007, 04:27 PM   #64
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Quote:
Originally Posted by Braineack View Post
this is the best i can do.

remember I know nothing about electronics....all im trying to do it give the ecu something to work with....it usually sees a 0-5v signal that changes as the heated element cools. Or at least trick the ecu that something is there...



Can I get someone that still has their MAF plumbed in to measure the following values for me with the car running (after 15 seconds so the sensor get's fully warm).

1) Voltage drop between pins 4 & 5
2) Resistance between pins 4 & 5
2) Resistance between pin 4 & GND
3) Voltage between pin 4 & GND

I would do it, but I don't have my MAF plumbed in, so I wouldn't have any airflow over it to make the readings accurate. Since the ECU is kicking a code with it plugged in and no flow those values will do me no good.

Best way to probe those points with the MAF plugged in is to either stick a needle through the insulation or push a piece of jumper wire through the rubber grommets on the connector.
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Old 12-22-2007, 05:20 PM   #65
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Ill do that for you tomorrow morning, ill be up early. My MAF is still plumbed.
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Old 12-22-2007, 05:31 PM   #66
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excellent, thanks. also, you might want to take some pictures of how you hook up the meter for each. there is always someone around here who will question the test setup.
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Old 12-22-2007, 06:45 PM   #67
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Quote:
Originally Posted by Arkmage View Post
excellent, thanks. also, you might want to take some pictures of how you hook up the meter for each. there is always someone around here who will question the test setup.
Alright. Ill do that too.

Btw, which pin should I use as ground 1 or 2?
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Old 12-22-2007, 10:07 PM   #68
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Alright. Ill do that too.

Btw, which pin should I use as ground 1 or 2?
for these tests I'd use chassis ground. I usually stick the probe on the side of the cylinder head or on one of the shock tower bolts.
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Old 12-24-2007, 10:42 AM   #69
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Sorry I didnt get around to it yet, holidays and stuff are all piling up.
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Old 12-24-2007, 11:55 AM   #70
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no problem... I'm leaving to see my grandparents on the 26th and won't be back to my car until the 1st. take your time and enjoy the holidays.
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Old 12-29-2007, 04:29 PM   #71
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Tomorrow you will have the numbers, im gonna have all morning free.

I am bumping this so I can remind myself and make sure to do it so I dont look like a tool saying twice I will do something and then not doing it.

Quote:
Originally Posted by Arkmage View Post
Can I get someone that still has their MAF plumbed in to measure the following values for me with the car running (after 15 seconds so the sensor get's fully warm).

1) Voltage drop between pins 4 & 5
2) Resistance between pins 4 & 5
2) Resistance between pin 4 & GND
3) Voltage between pin 4 & GND

I would do it, but I don't have my MAF plumbed in, so I wouldn't have any airflow over it to make the readings accurate. Since the ECU is kicking a code with it plugged in and no flow those values will do me no good.

Best way to probe those points with the MAF plugged in is to either stick a needle through the insulation or push a piece of jumper wire through the rubber grommets on the connector.

Btw, are you sure its between 4 and 5 and not 3, 4 and ground? I mean, the 12v all it does is heat up the wire, the refrence voltage is probably 3 and 4.
or should I just do the whole battery of tests and probe everything?

Edit: btw, im not running my LC1 off the same wire as the Maf. Should I take it off that just in case?
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Old 12-31-2007, 05:11 PM   #72
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3 is the AIT, that is not the wire we want to probe off of.

the tests I asked for should be all we need. My inspection expires today, so it's time to get on the ball on this one. I have 5 days before I risk another ticket for being out of date.
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Old 12-31-2007, 09:19 PM   #73
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Man im sorry, freaking everything is canabolizing my time these last few days. My GF's mom fell from a flight of stairs and fucked up both arms so I had to go to hospital with them, her father bought a washing machine that needed to be picked up and installed today, I needed to take my GF food shopping so she can feed them, then on top of that my aunte called a short notice party for new years.

Ill get em for you first thing tomorrow. Everyone, including my GF should be hammered and no one will bother me.
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Old 01-01-2008, 03:16 PM   #74
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Quote:
Originally Posted by Arkmage View Post

1) Voltage drop between pins 4 & 5
2) Resistance between pins 4 & 5
2) Resistance between pin 4 & GND
3) Voltage between pin 4 & GND
1) DMM reads 13 volts
2) DMM reads 1.7 M Ohm
3) DMM shows no reading
4) DMM shows no reading
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Old 01-01-2008, 04:29 PM   #75
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right... so since you measured 13V differential between 4&5, that means the ECU is getting 14.7-13=1.7V at idle. Sounds reasonable. I'm thinking that a 1.7M-ohm resistor between 4&5 would deal with the MAF. I'll go take a look in a few.

*edit* Electrical Guys... please have a look at this and double check my logic/math. I verified the measured numbers and made a quick schematic for visualizing what is going on. I believe a 1.4-1.5 M-ohm resistor between pins 4&5 will take care of the MAF. The AIT can be bypassed as shown by Scott earlier in the thread.
Attached Thumbnails
94-95 & 96-97 MAF Delete Discussion-maf_delete_obd2.jpg  

Last edited by Arkmage; 01-01-2008 at 05:27 PM.
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Old 01-01-2008, 11:21 PM   #76
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no dice...that method generated a check engine light right off the bat...
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Old 01-02-2008, 12:22 PM   #77
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Hasn't the MS got some programmable outputs on it? Maybe I should just program an output to vary between 1-4V and jack that into the MAF line. Anyone still reading this thread?
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Old 01-02-2008, 12:46 PM   #78
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I am.

Did you plug the resistor into the AIT wire as well?
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Old 01-02-2008, 12:58 PM   #79
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me too, but i cant contribute anything, this is far beyond my capabilities
keep up the good work guys, i wish you luck and success, so then i can just copy what you did
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Old 01-02-2008, 12:59 PM   #80
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Im curious to the code it sent as well.
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