MAF Speed Density MAF to plain Speed Density - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**dec010974** · 03-30-2016, 02:06 PM

Hello to all. I currently have a Speed Density Tune on my LQ4/TH400 Swapped 1971 C10. At this time, I am using the MAF Sensor in place of the IAT Sensor used for Speed Density Tunes. I want to remove the MAF Sensor and use the IAT Sensor. Question #1-Which wires are used for A & B on the IAT Sensor connector? From my sources, the PCM uses Pin#25 and Pin#57, on the red PCM, C2 Connector for IAT Sources. Question #2-Is this correct? Question #3-Once the switch is made, will the tune need recalibration? Also, does the air have a higher temperature inside the intake manifold, rather than the engine bay? The Pictures are a depiction of the changes I want to make. Thanks in advance. Clark.

BR3W CITY · 03-30-2016, 02:54 PM

"the IAT sensor used for Speed Density" - exactly what sensor are you referring to? You can de-pin the MAF and keep its iat function, switch to an IAT-only sensor, or switch to a TMap.

**dec010974** · 03-30-2016, 04:41 PM

Like the picture shows, I want to use a IAT Sensor.

**dec010974** · 03-30-2016, 04:47 PM

This is a IAT Sensor.

BR3W CITY · 03-30-2016, 05:59 PM

Then ya its pin #25 as signal which should be the tan wire, the other side is sensor ground (i believe thats the one you've got as 57.

#25 would be the one you'd wire into a TMAP if you went that way.

**dec010974** · 03-30-2016, 08:33 PM

Pin #25-goes to A or B on the IAT connctor side?

BR3W CITY · 03-30-2016, 11:50 PM

Based on most GM IAT's, its A. (I don't actually know if it matters, but all the IAT wiring I have access to is pretty much the same. )

03-30-2016, 04:47 PM	#4
dec010974 Senior Member Join Date: Oct 2012 Location: Miami, Florida Posts: 959	Re: MAF Speed Density MAF to plain Speed Density This is a IAT Sensor. Attached Images

03-30-2016, 08:33 PM	#6
dec010974 Senior Member Join Date: Oct 2012 Location: Miami, Florida Posts: 959	Re: MAF Speed Density MAF to plain Speed Density Pin #25-goes to A or B on the IAT connctor side?

03-30-2016, 11:50 PM	#7
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: MAF Speed Density MAF to plain Speed Density Based on most GM IAT's, its A. (I don't actually know if it matters, but all the IAT wiring I have access to is pretty much the same. ) __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

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03-30-2016, 02:06 PM	#1
dec010974 Senior Member Join Date: Oct 2012 Location: Miami, Florida Posts: 959	MAF Speed Density MAF to plain Speed Density Hello to all. I currently have a Speed Density Tune on my LQ4/TH400 Swapped 1971 C10. At this time, I am using the MAF Sensor in place of the IAT Sensor used for Speed Density Tunes. I want to remove the MAF Sensor and use the IAT Sensor. Question #1-Which wires are used for A & B on the IAT Sensor connector? From my sources, the PCM uses Pin#25 and Pin#57, on the red PCM, C2 Connector for IAT Sources. Question #2-Is this correct? Question #3-Once the switch is made, will the tune need recalibration? Also, does the air have a higher temperature inside the intake manifold, rather than the engine bay? The Pictures are a depiction of the changes I want to make. Thanks in advance. Clark. Attached Images

03-30-2016, 02:54 PM	#2
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: MAF Speed Density MAF to plain Speed Density "the IAT sensor used for Speed Density" - exactly what sensor are you referring to? You can de-pin the MAF and keep its iat function, switch to an IAT-only sensor, or switch to a TMap. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

03-30-2016, 04:41 PM	#3
dec010974 Senior Member Join Date: Oct 2012 Location: Miami, Florida Posts: 959	Re: MAF Speed Density MAF to plain Speed Density Like the picture shows, I want to use a IAT Sensor.

03-30-2016, 05:59 PM	#5
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: MAF Speed Density MAF to plain Speed Density Then ya its pin #25 as signal which should be the tan wire, the other side is sensor ground (i believe thats the one you've got as 57. #25 would be the one you'd wire into a TMAP if you went that way. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD



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