MAFT Pro VF Signal Operation. When should it read ?????????

supraguy31

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May 10, 2005
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Pembroke, NC
MAFT Pro running Speed Density

When I start the car up and Im watching the AUX-1 signal how long does it take before you should start getting a reading... I do understand that it should read 0.00 for a minute or two until close loop and then start showing something after that.

Reason Im asking is that when I start my car up, I can let it run for 10 minutes and the AUX-1 signal will read 0.00. Now if I shut the car off and then turn it back on again, it starts to read somewhere in the 1.80-1.90v range. Im just really concerned about the Initial startup and why its taking so so long before I start seeing a reading.

What should I be looking for in Order to correct this. All connections are soldered in just incase someone is wondering.

Thanks in Advance
Robert
 

supraguy31

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May 10, 2005
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Pembroke, NC
Yes I agree.

I didnt have this Problem before on my Previous MAFT Pro but since I purchased another one and wired it in exactly the same this started. Funny thing that I get VF once I restart the car which should have nothing to do with it. VF should read weather the car is first started or not.

So any recommendations.

Running Maft Pro Version 5.22
 

supraguy31

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May 10, 2005
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hahaha.... I did that and TurboBob told me that since it sounds like a Supra Issue that It would be best that I post it where all the Supra gurus are.
 

supraguy31

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May 10, 2005
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Pembroke, NC
Can I check that at the Check connector or should I do it at the ECU. Hopefully its a easy fix but then again with these cars there isnt anything that seems to be easy sometimes.
 

supraguy31

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May 10, 2005
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Ok...

So I took my Digital Multimeter and did a Voltage check at the ECU. Waited for Approx 5 to 7 minutes and I finally got a AUX1 Signal. As soon as I got voltage at the ECU, the MAFT Pro Displayed the same Voltage so Its not a MAFT Pro Issue. Voltage at the ECU didnt come in until the time Above.

So Im assuming that this will rule out the MAFT Pro as being the Issue.
 

supraguy31

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May 10, 2005
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Pembroke, NC
Im running the Stock O2 Sensor and Its mounted in the Stock Location or Pretty close to it. About 6 to 8" for the 3" V-Band Flange. My Wide band is Mounted about 1 1/2 feet below that. Just to confirm that its a good Sensor, I have a Spare that I ran for quite a While and I installed that one also. Did the same thing so Im going to assume that this would eliminate the O2 sensor as being bad also.
 

GrimJack

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Run the resistance check on the sensor anyway... last item on the list in the TSRM as I recall, and easy to do. That checks the heater unit in it, which should get it up to operating temp much faster. It's reasonably common for that heater circuit to be dead.
 

supraguy31

New Member
May 10, 2005
626
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Pembroke, NC
Ok, so O2 sensor is good

Now Im really thinking its the harness. Im moving to a New location so yesterday I finally started the car up and took it over to the New House. Distance is about 18 miles and car started up fine as usual. Got out on the road and it drove a little in the Rich side (13.1-14.0) all the way to my Exit. So about a mile from the House I thought about it and reached over and opened the Glove box to see what the MAFT is reading.

0.00 VF after 16-18 miles of Driving.

Since I was on a Street that didnt have any traffic on it, I pushed in the clutch, Shut the engine off until the MAFT Pro went blank, Started the car back up and Instantly it starts to read VF of 1.90 +/-

Thinking wiring harness now as what else is there to check.....

Robert