Fuel injection? Open or Closed loop? - Page 4

KRatcliff · 07-16-2012, 04:06 PM

Which sensor?

Ed Wright · 07-16-2012, 05:02 PM

Kyle, he has to be talking about the IAT sensor.

Usually mounted in the air filter box or ducting. Can also be screwed into the intake manifold and set up as a MAT sensor. Lots of race cars running around without one, the diagnostic code shut off, and the correction table zeroed out. In Speed Density mode, most recommend a MAT sensor being used.

KRatcliff · 07-16-2012, 05:20 PM

Gotcha. I wasn't sure if he was referring to the MAP sensor which is in the proper position for Speed Density, but flipped up and the hole plugged for Alpha N.

Capri · 07-17-2012, 01:44 PM

Intake air temp sensor. For me, its a factory unit screwed into the lower intake. Just noticed alot of others let it flap in the breeze near the entrance to the TB. Just wondered if it helps something in the fuel curve control.

KRatcliff · 07-17-2012, 01:55 PM

Yes, it can help. If you see it out in the open air, like in front of the throttle body, then they are generally running it in Alpha N. Ed's post covered it pretty well.

Edited to add: I do use the air temp to affect my fuel curve to a small degree.

art leong · 07-17-2012, 06:55 PM

Quote:

Originally Posted by Capri

Intake air temp sensor. For me, its a factory unit screwed into the lower intake. Just noticed alot of others let it flap in the breeze near the entrance to the TB. Just wondered if it helps something in the fuel curve control.

I have mine screwed into the air box near the scoop. Works fine.

Capri · 07-17-2012, 09:22 PM

Art,

What I am wondering is if I plug the hole in the intake, and just leave it out in the open air, if it would change anything. Its not a problem or anything, but just a thing that makes ya go hmmmmmmmmm

Tony

Ed Wright · 07-17-2012, 09:26 PM

I wouldn't bother moving it.

art leong · 07-17-2012, 09:30 PM

Quote:

Originally Posted by Capri

Art,

What I am wondering is if I plug the hole in the intake, and just leave it out in the open air, if it would change anything. Its not a problem or anything, but just a thing that makes ya go hmmmmmmmmm

Tony

Mine is in the open air of the box I built around my throttle bodies. This picture was taken before I finished it The sensor is in the sheet metal.

Marine One · 07-18-2012, 11:23 PM

If you are concerned that the ambient temps are causing the ECM to pull timing, just adjust / eliminate the amount of timing being pulled via the AIT mapping.

View Poll Results: Fuel injection? Do you run in open loop or closed loop
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Closed Loop	39	33.62%
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07-16-2012, 04:06 PM	#31
KRatcliff Senior Member Join Date: Sep 2011 Posts: 753 Likes: 74 Liked 502 Times in 135 Posts	Re: Fuel injection? Open or Closed loop? Which sensor?

07-16-2012, 05:02 PM	#32
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 389 Times in 168 Posts	Re: Fuel injection? Open or Closed loop? Kyle, he has to be talking about the IAT sensor. Usually mounted in the air filter box or ducting. Can also be screwed into the intake manifold and set up as a MAT sensor. Lots of race cars running around without one, the diagnostic code shut off, and the correction table zeroed out. In Speed Density mode, most recommend a MAT sensor being used. __________________ Ed Wright 4156 SS/JA

07-16-2012, 05:20 PM	#33
KRatcliff Senior Member Join Date: Sep 2011 Posts: 753 Likes: 74 Liked 502 Times in 135 Posts	Re: Fuel injection? Open or Closed loop? Gotcha. I wasn't sure if he was referring to the MAP sensor which is in the proper position for Speed Density, but flipped up and the hole plugged for Alpha N.

07-17-2012, 01:44 PM	#34
Capri Member Join Date: Apr 2004 Posts: 171 Likes: 0 Liked 29 Times in 15 Posts	Re: Fuel injection? Open or Closed loop? Intake air temp sensor. For me, its a factory unit screwed into the lower intake. Just noticed alot of others let it flap in the breeze near the entrance to the TB. Just wondered if it helps something in the fuel curve control.

07-17-2012, 01:55 PM	#35
KRatcliff Senior Member Join Date: Sep 2011 Posts: 753 Likes: 74 Liked 502 Times in 135 Posts	Re: Fuel injection? Open or Closed loop? Yes, it can help. If you see it out in the open air, like in front of the throttle body, then they are generally running it in Alpha N. Ed's post covered it pretty well. Edited to add: I do use the air temp to affect my fuel curve to a small degree. Last edited by KRatcliff; 07-17-2012 at 01:57 PM. Reason: Forgot something

07-17-2012, 09:22 PM	#37
Capri Member Join Date: Apr 2004 Posts: 171 Likes: 0 Liked 29 Times in 15 Posts	Re: Fuel injection? Open or Closed loop? Art, What I am wondering is if I plug the hole in the intake, and just leave it out in the open air, if it would change anything. Its not a problem or anything, but just a thing that makes ya go hmmmmmmmmm Tony

07-17-2012, 09:26 PM	#38
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 389 Times in 168 Posts	Re: Fuel injection? Open or Closed loop? I wouldn't bother moving it. __________________ Ed Wright 4156 SS/JA

07-18-2012, 11:23 PM	#40
Marine One Junior Member Join Date: Mar 2010 Location: Indiana Posts: 69 Likes: 1 Liked 0 Times in 0 Posts	Re: Fuel injection? Open or Closed loop? If you are concerned that the ambient temps are causing the ECM to pull timing, just adjust / eliminate the amount of timing being pulled via the AIT mapping. __________________ Chad Sheets \| STK 319 \| 10.69 \| 1.39