Maf iat - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dwcsr · 07-09-2011, 01:42 AM

What is everyone doing with the MAF and IAT. Can these be deleted or do they need to be connected. I have a 2000 4.8 truck pcm. I'm keeping the 4l60e and removing the 2nd o2 sensors, the pruge system and the EGR system.

The other question is the motor was a 4.8 and is now a 5.3 with a LS1 cam. Do I need to retune the PCM or can I let it go with the usual deletes.

BR3W CITY · 07-09-2011, 02:31 AM

you need to run the maf and IAT unless you decide to run an SD tune. Even so, you'd need to relocate the IAT.

As for the motor question; if vats and all that stuff has already been done, I think it should be able to start just fine. The issues I can see would be the cam and increased displacement would demand a bit more fuel than a stock 4.8 tune would want to do. It would probably be worth a re-tune on the dyno to make the most of the changes.

dwcsr · 07-09-2011, 03:42 AM

On this the MAF and IAT are one unit so I guess I need to leave that in the harness. As long as it starts I can always have it dyno tuned when I get it on the road. I'm a little lost on the Lsx stuff, most of what I work on is old iron (pre 1963) and a starter that works off the key is as high tech as I get.

BR3W CITY · 07-09-2011, 12:56 PM

my starter still works off the key

The iat can be relocated out of the MAF if you get a Speed Density tune, but it seems like there really wouldn't be a benefit to you.
When I got mine tuned, we just dumped a "start tune" into the pcm. It was basically the stock truck tune; 02, vats, egr, a/c control deletes. We threw a few points extra fuel at it just so it wouldn't go lean until we had a chance to get it on the dyno. It started first try and was PLENTY capable of getting down the road.
Good luck!

dwcsr · 07-09-2011, 02:39 PM

Thanks for the info. I just purchased a maf/iat combo and will wire it in. That will pretty much finish the motor and on to the clip.

07-09-2011, 01:42 AM	#1
dwcsr Hollister Road Co. Join Date: Apr 2005 Location: Houston Posts: 6,131	Maf iat What is everyone doing with the MAF and IAT. Can these be deleted or do they need to be connected. I have a 2000 4.8 truck pcm. I'm keeping the 4l60e and removing the 2nd o2 sensors, the pruge system and the EGR system. The other question is the motor was a 4.8 and is now a 5.3 with a LS1 cam. Do I need to retune the PCM or can I let it go with the usual deletes.

07-09-2011, 02:31 AM	#2
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: Maf iat you need to run the maf and IAT unless you decide to run an SD tune. Even so, you'd need to relocate the IAT. As for the motor question; if vats and all that stuff has already been done, I think it should be able to start just fine. The issues I can see would be the cam and increased displacement would demand a bit more fuel than a stock 4.8 tune would want to do. It would probably be worth a re-tune on the dyno to make the most of the changes. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

07-09-2011, 03:42 AM	#3
dwcsr Hollister Road Co. Join Date: Apr 2005 Location: Houston Posts: 6,131	Re: Maf iat On this the MAF and IAT are one unit so I guess I need to leave that in the harness. As long as it starts I can always have it dyno tuned when I get it on the road. I'm a little lost on the Lsx stuff, most of what I work on is old iron (pre 1963) and a starter that works off the key is as high tech as I get.

07-09-2011, 12:56 PM	#4
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: Maf iat my starter still works off the key The iat can be relocated out of the MAF if you get a Speed Density tune, but it seems like there really wouldn't be a benefit to you. When I got mine tuned, we just dumped a "start tune" into the pcm. It was basically the stock truck tune; 02, vats, egr, a/c control deletes. We threw a few points extra fuel at it just so it wouldn't go lean until we had a chance to get it on the dyno. It started first try and was PLENTY capable of getting down the road. Good luck! __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

07-09-2011, 02:39 PM	#5
dwcsr Hollister Road Co. Join Date: Apr 2005 Location: Houston Posts: 6,131	Re: Maf iat Thanks for the info. I just purchased a maf/iat combo and will wire it in. That will pretty much finish the motor and on to the clip.



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