Took air sencer off of cool box when working on truck. Decided too put it were outside cool air could hit it. Doubled the power but shifted pourly. Why?

You need to move the trans cooler to the passenger seat to balance it out.

wtf are you talking about?

engrish pwease

Kinda like when you put closepin's on your fuel

Just thinking out load dieselplace told me to say something

As a child I remember shooting mud ducks with a pistol. That was a long time ago....

Can you tell me why or are you just a smart ass!

pro400ex must be having some more multiple-username fun ;)

na just dont play well with like that mr. rat. Was just asking QU!

Whats a dual feed injector pump?

I could tell you why but I don't wanna.:muahaha:

ok heres an answer for ya 1) the truck ran harder because it thought it had colder incoming air colder = denser air charge (more air) so it adds fuel to compensate. more power!! just another fancy electronic feature of a self regulating efficient power making machine.. hope that helps the trans was shifting harder due to it having to learn that section of parameters. 2) when u see posts by the smart asses that refuse to help u with your question just say " could help you but ------no!" they have forgotten they dont know it all and we dont wanna hear about it.
:rant:

where is the sensor he is talking about do you have any pics

Took air sencer off of cool box when working on truck. Decided too put it were outside cool air could hit it. Doubled the power but shifted pourly. Why?

If you want to be taken seriously, please post seriously. This doesn'ty make sense. What is a "cool box"?

Are you talking about the MAF sensor?

Thank you dmaxtechrenol. I now what the parts are called but it is very hard for me to spell so i do the best i can. Sorry for bad gramer. I am getting better. I 48 years old never had chance to go to school. I realy like trying to get all i can out of diesel's. Be it my drilling rig motors, Semi's or the 4 duramax pickups i have 3 2006 and 1 2001 and this site helps. Remember Nwdmax but not for the grace of GOD their go I.

Will it hurt any thing if i place the sencer away from heat of motor.

Nobody is sure what sensor you are refering to.

the air flow sencer on the air intake pipe.

If it's the MAF, it is a flow sensor. Taking it out of the intake has taken away the ability of the ECM to measure intake air flow and perform necessary calculations for timing, boost and injection. Cooling has nothing to do with it. I can't believe it hasn't thrown a code and check engine light. Not an acceptable modification in my opinion.

The maf sensor appears to be primarily a temp sensor. Our fueling tables are MAP driven, and the MAF sensor is used primarily in diagnostics (code issues as you point out Tom).

Keep in mind this is the system as I know it. Hope I got it right. Actual mass air flow is not an input for engine function. Not that I understand why it is this way (like a gasser), I really do not. Something about air/fuel stoich...

That said, a colder signal on the sensor should send more fuel. I will have to check efi to back up this statement.

The maf sensor appears to be primarily a temp sensor. Our fueling tables are MAP driven, and the MAF sensor is used primarily in diagnostics (code issues as you point out Tom).

Keep in mind this is the system as I know it. Hope I got it right. Actual mass air flow is not an input for engine function. Not that I understand why it is this way (like a gasser), I really do not. Something about air/fuel stoich...

That said, a colder signal on the sensor should send more fuel. I will have to check efi to back up this statement.

The MAF is combined with the IAT sensor (both functions in same unit).

From the service manual:

The IAT sensor sends a signal to the PCM relative to the incoming air. The IAT is used by the ECM to adjust fuel delivery.

The MAF sensor indicates the amount of air entering the engine through the mass air flow sensor.

So you are right that the cooler air would affect fuel delivery calcs. I have to dig deeper to see what the MAF really does in the mix.

Until recently, I was under the impression that accuracy was important with the MAF sensor. Now I find nothing, except that it is used as a comparator for egr proper operation.

And IAT, of course, which is an input to just about all the tuning parameters.

ok the maf sensor incorporates two sensors in one a incoming air meter that measures speed,density and volume of incoming air and the other sensor is the intake air temp sensor it measures the temp of the incoming air charge and both of these reading are CRUCIAL to proper operation of the engine management while it is true that the ecm also uses the reading to determine the status of he egr system it needs these sensors to make it run. any of you use a k&n style filter and had a problem with the maf sensor due to the oil from the filter? want to find out what the sensor does remove it from the tube leavin it pluged in and start the truck and drive it around the block lucky to get to 2000 rpm no power. if you were inovative you get another sensor route he iat sensor out of the intake by movin the associated wiring but the gains would be minimal if any and could cause other issues. reccomend cold air box / modify stock box toallow ar in from below. there are threads on this topic on dp. good luck.

The best I can tell, this is supposed to be a comedy thread.

But since we seem to turn everything technical:

Someone with EFILive check to see if the early LB7 is MAP or MAF mapped. I believe it's MAP mapped. If so, the only reason you'd see a huge power gain would be if there were DTC's that put the truck into limp mode and relocating the MAF stopped it.

I'll try to keep it comedic(not sure if thats a word). Its all good Mud. If it was a serious question I apologize.
What prompted you to try this "mod" in the first place?

Blake

Man I just love this place! People are always thinking outside the box.
(Yes a poor pun but also very true).

With about 8" of wire connecting the MAF to the harness, you couldn't have possibly moved it to a much cooler location... Clean it, and put it back in the airbox.

ok the maf sensor incorporates two sensors in one a incoming air meter that measures speed,density and volume of incoming air and the other sensor is the intake air temp sensor it measures the temp of the incoming air charge and both of these reading are CRUCIAL to proper operation of the engine management while it is true that the ecm also uses the reading to determine the status of he egr system it needs these sensors to make it run. any of you use a k&n style filter and had a problem with the maf sensor due to the oil from the filter? want to find out what the sensor does remove it from the tube leavin it pluged in and start the truck and drive it around the block lucky to get to 2000 rpm no power. if you were inovative you get another sensor route he iat sensor out of the intake by movin the associated wiring but the gains would be minimal if any and could cause other issues. reccomend cold air box / modify stock box toallow ar in from below. there are threads on this topic on dp. good luck.

I completely unplugged it and ran around town, no casually observable effect as I recall, though it was a month ago, as best I can remember. Did have a code or 2. Like Mcrat and I said earlier, map driven tuning, unlike most other vehicles that are MAF driven..

Well, I've done some further research. It's nice on a snowy Sunday morning to snuggle up on the couch with a mug of coffee and Volume 4 of 5 of GMT/01-CK8-4, Engine Controls - 6.6L (NOT, BTW, on Oprah's book club list!) There are several DTCs that will be thrown if the MAF is not seeing calculated values. The book is a little hard to research, because it is a *service* manual and therefore works backwards from DTCs and you have to scan the individual DTCs to find information about the affected sensors. Anyhoo, my findings are that MAF is used to control fueling for emissions only and apparently at low speed and rpm.

Quote:

"The engine control module (ECM) uses the MAF sensor voltage signal in order to provide the correct fuel delivery for a reduction in emissions. The ECM uses the MAF sensor signal in order to control fuel delivery until a calibrated amount of engine air flow is attained."

DTC P0101, MAF sensor out of range has the following conditions for being set:

engine speed less than 2,500 rpm
Accelerator pedal position less than 50%

This tells me that then MAF is for emissions control at low speeds only - it may also tie into EGR operation for emissions, also.

The MAF DTCs are for low, high and out of range and all throw a MIL (CEL).

I believe you will not notice a MAF disconnect performance wise, just the DTC and CEL since it's a low speed issue.

IAT, on the other hand is pretty important to the ECM and MAP driven injection, so there may be some more serious issues there if you were to "fool" the system by telling it you had much cooler (and denser) intake charge.

On review, I withdraw my comment on performance changes with the MAF disconnected. This is the source for "low boost fueling" since the MAF signal will deny fueling until the turbo spins up (apparently assuming that over 2500 rpm/50% APP you are "boosted"). With low MAF flow indicated (out of the box) you are denying fueling as the ECM waits for turbo spoolup.

Also, as Max Payne noted, out of the box and still underhood is not going to make much difference to IAT.

good stuff, as always Tom

Took air sencer off of cool box when working on truck. Decided too put it were outside cool air could hit it. Doubled the power but shifted pourly. Why?

Back to the original post, I think I've solved the "extra power but shifted poorly" question. With the MAF out of the airflow, engine fueling and torque management were boogered up. Fueling was being witheld waiting for turbo spoolup until rpm got out of the emissions control band (under 2500 rpm) and then being "dumped" once the low MAF flow couldn't suppress it any more. There was a surge and it made it hard for the ECM/TCM to properly adjust shift points based on torque management. I think there was no "massive power increase" just a sensation of surge after an overall loss of low end power. Once again "there is no free lunch.";) :muahaha: