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Discussion Starter #1
Well I did the seafoam, got really gas mileage and then it fell off and went back down. So I took the intake off and looked at the MAF sensor, it was black, the connectors were black and it looked ugly. So I unhooked it and since I didnt have maf cleaner at the moment I just took some water and cleaned what I could off and then took a soft cloth and cleaned the rest. It looks 100x better. However I was wondering if anyone has used the maf cleaner? Did it work for you? I did notice that my idle went up a little to like 800rpms were it was at 500rpms before.
 

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What car are you talking about? Ours do not use a MAF sensor. They use a MAP sensor. Big difference.
 

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Discussion Starter #3
whatever the sensor is.....the one that is in tube before throttle body.
 

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IAT maybe. What engine?
 

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Discussion Starter #5
yes the IAT sensor. I drove it around last night and it was running better under acceleration. I still am curious about the MAF cleaner and can I use it on the IAT every once in awhile to keep it nice and clean?

2.7l
 

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MAP is Manifold Air Pressure..
MAF is Manifold Air Flow?
 

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Discussion Starter #7
okay...got it already. Sorry someone referred to it as a MAF sensor so thats what I thought it was. Didnt realize it was a big deal. I now know its a IAT that I was talking about!!! Thanks for letting me know.
 

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Not a deal--I didn't know what you spoke of, and I wanted to figure it out..
Always liked acronyms...
 

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Well, its kind of a big deal since they perform different functions. The MAF and MAP perform similar functions. But you probably won't find them both on the same engine. The MAP sensors are used on speed/density systems and MAF's are not. And then the IAT is something else altogether. As the name implies, it measures the intake air temperature. I thought it was mounted in the intake plenum, but I don't see why you can't use a cleaner on them. I've seen an IAT and I'd imagine you'd need a good amount of build-up on them to really throw off its reading.
 

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Discussion Starter #10
Sorry, really bad day yesterday. I understand the difference after getting the right name because I did some research, and finding were are MAP sensor is. I would suggest cleaning the IAT because it seemed to help alot. But do what you want.
 

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froggy81500 said:
And then the IAT is something else altogether. As the name implies, it measures the intake air temperature. I thought it was mounted in the intake plenum, but I don't see why you can't use a cleaner on them. I've seen an IAT and I'd imagine you'd need a good amount of build-up on them to really throw off its reading.
Hey, froggy... I can't find anything in the Factory Service Manual about an
IAT (intake air temperature)...
Closest I get is the IAC (idle air control) motor. That's in the intake;(page 14-29, fig.10 and 11), a steeper motor that controls a pintle that opens/restricts air flow to control idle speed. The ECU(or PCM, whatever...)
takes signals from the gear position,battery voltage, ambient and battery temperatures,VSS,(I think, vehicle security system), TPS (throttle position sensor), MAP sensor, and ECT sensor (engine coolant sensor) and tells the IAC
where it's supposed to be, and result is a correct idle speed.
Is that what you're speaking of?
 

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alarkyokie said:
Hey, froggy... I can't find anything in the Factory Service Manual about an
IAT (intake air temperature)...
Closest I get is the IAC (idle air control) motor. That's in the intake;(page 14-29, fig.10 and 11), a steeper motor that controls a pintle that opens/restricts air flow to control idle speed. The ECU(or PCM, whatever...)
takes signals from the gear position,battery voltage, ambient and battery temperatures,VSS,(I think, vehicle security system), TPS (throttle position sensor), MAP sensor, and ECT sensor (engine coolant sensor) and tells the IAC
where it's supposed to be, and result is a correct idle speed.
Is that what you're speaking of?
No, I know the difference between the two. I was pretty sure we had an IAT on these motors, but maybe we don't. the IAC is a motor/solenoid to control the idle. The IAT on the other hand is very similar to the CTS, except it measures air temp not coolant temp.

Yes, 98_2.7TREP MAP is Manifold Absolute Pressure. MAF is Mass Air Flow. You won't find BOTH on the same car because they are two different air flow monitoring systems.
 

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alarkyokie said:
Hey, froggy... I can't find anything in the Factory Service Manual about an
IAT (intake air temperature)...
Closest I get is the IAC (idle air control) motor. That's in the intake;(page 14-29, fig.10 and 11), a steeper motor that controls a pintle that opens/restricts air flow to control idle speed. The ECU(or PCM, whatever...)
takes signals from the gear position,battery voltage, ambient and battery temperatures,VSS,(I think, vehicle security system), TPS (throttle position sensor), MAP sensor, and ECT sensor (engine coolant sensor) and tells the IAC
where it's supposed to be, and result is a correct idle speed.
Is that what you're speaking of?
Very next page 14-30 has only a brief instruction on removing and reinstalling the IAT. My wife's got my trep so I can't go out and look for it at the moment. I looked at a few different parts sites and they list one, for my '01 2.7L anyway.

Edit- found it. I remember I had some pics on photobucket of the heat exchanger for the pcv adn sure enough there was enough of the plenum in the pic to show it. It is on the driver's side between the #5 and #6 coils. Its shown in this pic with the brass base.

 

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Discussion Starter #15
okay, well I was talking about the little sensor that plugs into the intake tube, the very last bend before the intake. Not anything to do with the drivers side, or the pcv.If I had a digital camera to show you I would, but I dont. If you have done any type of work on your intake then you should have seen it if you took off the last bend on a 2.7L
 

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froggy81500 said:
No, I know the difference between the two. I was pretty sure we had an IAT on these motors, but maybe we don't. the IAC is a motor/solenoid to control the idle. The IAT on the other hand is very similar to the CTS, except it measures air temp not coolant temp.

Yes, 98_2.7TREP MAP is Manifold Absolute Pressure. MAF is Mass Air Flow. You won't find BOTH on the same car because they are two different air flow monitoring systems.

Not true. My mazda has both MAS/MAF and MAP sensors.
 

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LT.Almond said:
okay, well I was talking about the little sensor that plugs into the intake tube, the very last bend before the intake. Not anything to do with the drivers side, or the pcv.If I had a digital camera to show you I would, but I dont. If you have done any type of work on your intake then you should have seen it if you took off the last bend on a 2.7L
??? Unless they did something different on the '04, I have no idea wht that is.
I just did some more searching at Rockauto and see that the '02 and '03 use a different one than my '01. Its completely made of black plastic with no threads, unlike mine that has a brass threaded base. I didn't find one listed for the '04 but my guess is its the same as the '02 & '03. Not sure why theymoved it, but you're right its the IAT. What holds it in there a c-clip or something? It doesn't have a threaded base but does have a groove in it, so my guess is something like a c-clip. Very odd, I'd like to know why they moved it from the plenum to the intake tube.
 

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FunkRider said:
Not true. My mazda has both MAS/MAF and MAP sensors.
Really? wow, maybe on the newer stuff they have managed to work them together. Typically there was either the Mass Air system with a MAF, or the speed/density system with a MAP. I think I'm gonna look up some GM vehicles that I know used a MAF and see if they also had a MAP. I guess its true that we learn something new everyday.

Edit* 2001 Firebird T/A lists both a MAP and MAF. I guess my mind is stuck back in OBDI technology. I gotta get with the times!
 

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Discussion Starter #19 (Edited)
here is what I found out about the IAT sensor from another site.....\

The IAT sensor reads the temperature of the air coming into the engine. The computer uses this to determine how much gas to give the engine, the colder the temp is, the more gas it gets, and vice versa (like a choke on a carburator). I don't know where it's located on the new hemi, but on my '98 5.9 Ram, it's mounted to the intake manifold, which is hot as hell. I relocated mine to the air intake tube, which is cooler air, tricking the computer into thinking it's cold, and it gives the engine more gas.

The IAT mod, if it's what I'm thining of, is nothing more than a resistor, which you can buy for less then $1 for Radio Shack. There are 2 ways that I've heard of doing it. One is to jumper the plug to your IAT with the resistor, The other is to splice the resistor into one of the wires on the IAT. If it's too high of a resistance, your truck will run like crap because it's getting too much gas.

Another option, and the one I did, was to relocate my IAT from the intake manifold to the actual ait intake tube before the air filter. It cost like 35 cents to get a plug to put in the manifold where the sensor was, and just a few minutes to drill a hole in the air box to mount the IAT there. Now I did this on a '98 Ram with a 5.9, I have no idea where your IAT might be located on the new hemi, but I would try it the way I did if I were you. That way, if you don't like it, all you have to do is put it back where it belongs and plug the hole in the air intake, you don't have to worry about splicing wires, and The reading your computer gets will vary with the actual air temp, it just gets a reading of cooler air.

When I did it, I had a check engine light, but that went away by disconnecting the battery. I haven't had any problems since. It's really hard to tell if it improved performance, but I think it did. However, it didn't effect my gas mileage at all, so really, what can it hurt?


Personally I think this is one thing Dodge did right, but only for the 04 guys it seems. Mine is already relocated to the intake tube, I like the idea of putting it closer to the box though since it will have even colder air then were it does now. :) maybe it could be a mod for all of us now. Dont know.
 

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I've heard about that mod before, about relocating the IAT down farther.

And those EBay chips are just that, a resistor to give the pcm a cold air reading and richen up the mixture. I understand it in theory, but one thing that "red flags" it to me is that if a resistor is in place of the IAT, then its output will never change and I see that as a potential problem at the pcm. It'll read that the CTS changed as the car warmed up but the IAT didn't so my thought is a CEL for the IAT. Now, if the resistor were spliced in series (in-line) with the IAT, the resistance gets added to the resistance of the IAT. In that case, the IAT will still function but depending on the value of the resistor used, it'll read a whole lot colder than without it. The higher the resistance, the colder the pcm interprets the air temperature is. But, another thing the pcm does is compare the values of the IAT and CTS and if they aren't within a certain amount at a cold start-up (as they should be close) then that might also trip a CEL.

As far as relocating the IAT, I think putting it in the top of the stock air box cover would be a good spot. Its far enough from the engine so that its not picking up a whole lot of heat. When I got a few more minutes, I'll do a comparison of specs for the 2001 that had it in the plenum and the '02 and up that has it in the air tube and see if there's any difference in power and/or torque that might be attributed to relocating the sensor.
 
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