I have a 1993 F150 with the 4.9L. I saw on a video online a recommendation to relocate the air intake temp sensor so that it's on the box with the air filter, just after the filter, and away from the heat of the engine. Is this something I should look into? Asking because I already had the sensor out since I have the head off the engine at the moment.

 

On the intake is the most accurate temp for fuel mixture calculations. It’s reading the air just before it enters the combustion chamber. If you move it somewhere else, you need to be able to remap your fueling based off that.

 

Okay. So just make sure the sensor is clean then, right?

 

I have looked into this before, never have I found any solid dyno charts or PCM data showing it is worth the hassle

 

Clean and operational. You can do a resistance check with a blow dryer heating it up.

 

I kinda wonder if it's a J type or K type thermocouple in this thing. We use one type with some of our test equipment at work, but the circuit board reflow oven uses the other type. Only reason I know that is I was asked to help diagnose an issue with the oven lately. We only use it for prototyping runs, so it doesn't get near the use it did before our company was acquired by big blue.

 

Can’t answer that! Way out of my league haha!

 

Whichever type it is, I can't just use the Fluke 179 at the office to read it directly, so it's not a k-type. In any case, at room temp it's reading around 33k, and it goes down when I breathe on it, like any other ntc thermistor. So the thing is good in my book. It was caked in grime when I first pulled it out. You wouldn't have known that the thermistor in the middle was red instead of black, and you couldn't tell the shape of it either. Most of a can of MAF cleaner got it cleaned up nicely though.

 

Yeah, these intakes love to get oily. Check Pcv valve. I put an oil catch can to assist with that also. It collects a lot..

 

No. The PCM in your truck is calibrated for the temperatures the sensor would report in its current location, those temps would be vastly different at the airbox and would make the computer think the engine never reaches operating temperature. Ford moved the sensor to the airbox on some later models but the computer would be tuned differently for that location.

 

The airbox location is specific to a MAF computer & intake for Speed Density.

The MAF computer needs the closest air temp to the MAF sensor to do its calculations.