Crazy IAT2 temps = bad sensor?

[1990stanggt]

Hey guys, did some more datalogging today and did the IAT2 temps for the first time. It randomly jumps between 0 , 60 and 128......bad sensor? Just to make sure, this is the sensor located on the passenger side in the lower intake right? I checked that sensors connections and everything seems ok....:shrug:

 

[inuswo]

Passenger side front of the lower intake on the 99-00 model, and drivers side rear on the 01+ model I belive.

The sensors are pretty cheap, just kinda hard to get to on the 01+

You might also want to make sure it is faced properly.

 

[FordFanStan]

Sounds like a bad sensor to me. Replace it and you should be good to go. FFS

PS. Just checking, but you were trying to monitor "Downstream Air Temp" correct?

 

[1990stanggt]

FordFanStan

Correct, it was downstream air temp according to LiveLink, shows up as iat2 when I transferred the config. to the Xcal3. As far as what this could be causing, would it hurt performance any if the sensor is indeed faulty? I also get a code that indicates IAT2 sensor voltage low, so this just confirms the sensor is probably bad.

 

[1990stanggt]

Passenger side front of the lower intake on the 99-00 model, and drivers side rear on the 01+ model I belive.

The sensors are pretty cheap, just kinda hard to get to on the 01+

You might also want to make sure it is faced properly.

What do you mean by "faced properly" ?

 

[FordFanStan]

No it won't directly hurt performance, but indirectly when a sensor is bad; your ECU controls your engine parameters by reading what the sensors in the powertrain tell it is happening. So if it is saying your engine is not warm enough or too hot, your are rich or lean, your IAT's are too hot, etc it will be adding or taking away spark advance and adding or taking away fuel, so forth. FFS

 

[Zak Attack]

hmmm I need to check mine, it gives the same temp all the time.

 

[FordFanStan]

Zak your IAT2 sensor is static, or another sensor?

 

[Dbl G]

No it won't directly hurt performance, but indirectly when a sensor is bad; your ECU controls your engine parameters by reading what the sensors in the power train tell it is happening. So if it is saying your engine is not warm enough or too hot, your are rich or lean, your IAT's are too hot, etc it will be adding or taking away spark advance and adding or taking away fuel, so forth. FFS

Your contradicting yourself, yes it will hurt performance by; As you later stated in your own post;

Your ECU controls your engine parameters by reading what the sensors in the power train tell it is happening. So if it is saying your engine is not warm enough or too hot, your are rich or lean, your IAT's are too hot, etc it will be adding or taking away spark advance and adding or taking away fuel, so forth.


I would check as well the function of your I.C. pump and or if your an early model the possibility of a leaking I.C. if you have fluid loss.

 

[1990stanggt]

Thanks for the info fellas, I went ahead and ordered a new O.E. sensor from Rockauto so it will be here fairly soon. DBL_G: I have an 01 but the heat exchanger is an aftermarket one, and the pump is circulating.

Do you guys think this issue could cause intermitten backfiring? The truck does it pretty much constantly.....? I'll know for sure in the next week and let you guys know what happens.

 

[Dbl G]

If you have a back firing problem, you need to address that immediately. That can be caused by several conditions and none are good. Check your Plugs, C.O.P.'s, Tune, filters etc. Get that cleared up quickly.

 

[1990stanggt]

If you have a back firing problem, you need to address that immediately. That can be caused by several conditions and none are good. Check your Plugs, C.O.P.'s, Tune, filters etc. Get that cleared up quickly.

:uh oh: Yea that is why the truck rarely gets driven, plus, it's a little embarassing lol. Great news though, did the plug/unplug test with the COPS and quickly figured out the front cop on each side were no good! I just finished replacing both of them and WOW the truck drives so much better!! It's definitely noticeable at WOT but it's even more noticeable at light throttle. It is so much smoother!

I think there may still be one bad COP though. Replacing those two definitely cut back on the rough running issue ALOT, but it still does it within a small range of throttle. Only problem is, the other COPS all seemed good. I'll wait for the new sensor and maybe that'll clear up the other roughness for me. Thanks for all the help guys, it may have taken me a good 4 months, but I'm finally getting this truck running like it should be! :rockon: :beer:

 

[Dbl G]

Great news don't get lazy though check out those plugs where the C.O.P.'s were failing and the others as well. You may still have another gremlin.

 

[1990stanggt]

Yea there is definitely still something, I'll pull the plugs this weekend while I'm replacing that sensor and see how they look.

 

[Dbl G]

Fuel Filter been changed in a while?

 

[1990stanggt]

Yep, changed the fuel filter and plugs about a month ago while having the motor all torn apart to fix a spark plug hole.

 

[Zak Attack]

Passenger side front of the lower intake on the 99-00 model, and drivers side rear on the 01+ model I belive.

The sensors are pretty cheap, just kinda hard to get to on the 01+

You might also want to make sure it is faced properly.

That makes no sense to me, because my IAT2 sensor is on my 2nd runner on the passenger side.

 

[bgstew6]

correct he got the years reversed

 

[1990stanggt]

Hey guys, I pulled the plugs to the cylinders with the bad COPS. One is pretty fouled out, the other looks ok i think. (I'm not real good with plug conditions) Could the fouled plug be whats causing the slight roughness that changing the COPS didnt fix? Here is a pic:

 

[Dbl G]

Yes, to some degree.