| rugby |
How you doing guys?
For kicks i just purchased this power tuner from ebay, they claim to add 7 to 22 hp, it looks like a light dimmer. My question is, i have to plug it into the IAT sensor which is suposed to be on the air intake manifold or throttle body. Had a quick look, there are a few sensor in that area, could someone help me pinpoint that sensor so i can give you guys feedback on it's outcome.
Thanks |
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| eurohazard |
| It would help if stated the year of your MDX. |
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| rugby |
| 02, Didin't think there were any changes as such to the engines. |
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| eurohazard |
It is possible the actual intake plumbing/sensor system is the same. I just know that at some point they went to drive-by-wire throttle, and I thought the sensors would be different.
On my 2004, I see one sensor right before the throttle body, and I think this is the sensor you're looking for. It has a green and a red wire going to it.
How much did you spend on the e-Bay part? |
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| rugby |
Thanks for the quick reply,
I think it was something like $80, around the throttle body i see 3 sensors and the only one with a 2 wire connection is actually bolted on top of the throttle body itself. The tuner has only 2 wire red and black.
Don't really want to start splicing wires before i'm positively sure that's were it goes. |
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| frostyra |
| I hate to sound like an old curmudgeon (which I am), but before you decide to modify your vehicle, buy the service and electrical troubleshooting manuals! Otherwise, it's like target shooting in the dark. |
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| DaleB |
$80? How about $49.99.
http://cgi.ebay.com/ebaymotors/ws/e...sspagename=WD1V
The intake air temp. sensor is located at the rear intake manifold chamber, closer to the drivers side. Near the very right end (as you face the engine) of the chamber
Not sure you can access it without taking off the plastic manifold top cover. |
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| rugby |
| Thanks very much will take a look, by the way $50US, pretty close to $80 Canadian. |
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| DaleB |
quote:
Originally posted by rugby
........, by the way $50US, pretty close to $80 Canadian.
Location, location, location! Someday I'll learn! :D |
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| 93springer |
There is a guy on ebay selling a 33K ohm resistor to be installed on the plug for the IAT sensor. He claims that it gives up to 20HP gain. Has anyone tried this? I just bought a 05 Pilot and I am tempted, but want to find out if anyone has any experience with this. Don't worry, I won't pay the guy $10 for a 2 cent resistor...I will get it from Radioshack.
Thanks |
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| SuperTech |
| This modification is simple and probably effective, but there is a risk and a comprimise to be made. It will fool the computer by making it think that the air temperature is much lower than it actually is. Cooler air is more dense, and that requires more fuel to balance out to keep a proper air/fuel ratio. So with this modification in place, your engine will be injecting more fuel to compensate for a false condition. A richer mixture may yield more power, but it most certainly will reduce fuel economy under all load conditions. And there is also the chance that this may cause the check engine light to come on because the computer will see that the mixture is too rich based on what it sees from the oxygen sensor(s). Prolonged running rich may prematurely reduce the catalytic convertor's efficency as well. |
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| memphor |
i saw the following on another forum:
"The modification sounds good but there is that “but” thing. You see the PCM only looks at the intake charge temperature during warm up open loop conditions so the added performance can be had but just for a short few minutes.
After that when the PCM goes into closed loop it doesn’t care what the charge temp is because O2 sensors are monitored for correct fuel delivery and the IAT will not be able to control timing anymore because the CTS (coolant temp sensor) has told the PCM the engine is warmed up.
O2 sensors are the big guns but can’t come on line during start ups because exhaust temps are too low.
If many users do lots of short trips with many warm up cycles than a little more advance will help MPG and Performance. Those that do longer trips will never see results from a degree or 2 in the morning start ups." |
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| 93springer |
Guys,
Thanks...I really appreciate all the good technical info. I have decided that the disadvantages outweigh any potential benefits. I was kind of shopping around for some low cost add-ons that might improve HP and/or fuel economy. It seems like this resistor across the AIT sensor is just a hoax that someone dreamed up to make some money on-ebay. Another one is the "Turbonator". You should read all the crazy messages about that one. What do you guys think about K&N filters. Any advantage in more air to the intake?
Thanks again,
93Springer |
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| memphor |
| I did replace the stock air filter with the k&n air filter. most chain auto stores carry the k&n air filter. does it improve HP and mileage? i can't say for sure. i just feel that it has better air flow than the oem paper filter. all my vehicles have the k&n air filter. the thing is you only have to buy it once. cleaning them is a piece of cake. make sure to pick up the cleaning kit when you buy the filter. there is no prep work needed for a new k&n filter. out of the box the filter is ready to install. |
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| SuperTech |
quote:
Originally posted by memphor
i saw the following on another forum:
"The modification sounds good but there is that “but” thing. You see the PCM only looks at the intake charge temperature during warm up open loop conditions so the added performance can be had but just for a short few minutes.
After that when the PCM goes into closed loop it doesn’t care what the charge temp is because O2 sensors are monitored for correct fuel delivery and the IAT will not be able to control timing anymore because the CTS (coolant temp sensor) has told the PCM the engine is warmed up.
O2 sensors are the big guns but can’t come on line during start ups because exhaust temps are too low.
If many users do lots of short trips with many warm up cycles than a little more advance will help MPG and Performance. Those that do longer trips will never see results from a degree or 2 in the morning start ups."
The MDX uses heated O2 sensors. It's capable of going into closed loop condition as early as a couple minutes after you start up cold and drive off.
What you read on the other forum is correct...but in relation to this modification, it isn't. So fuel trim is controlled by the O2 sensors in closed loop. However, at wide open throttle, the system goes back to open loop. And horsepower (such as a gain from making this modification) would be measured at wide open throttle. In open loop, the computer determines fuel and spark curves based on readings from the Intake Air Temperature sensor among a host of other sensors.
As far as K&N filters...I'm back to OEM filters with replacement according to schedule. The last time I used one was about 5 years ago. The rubber seal didn't fit the airbox perfectly allowing dirty, unfiltered air to get into the engine. It needed to be cleaned much sooner than the interval for just replacing the stock filter was. Most owners after a while forget to clean and reoil it regularly, allowing it to pack up with dirt and actually rob horsepower from the engine. And I have seen dyno tests of cars that have no other modifications except a K&N air filter yield absolutely zero gain in horsepower. And these were on cars that displace much more than a 3.5L V6 MDX has. And another side effect for those of you who are considering using these on other vehicles...is the oil. Yes the Honda filter is damn near dripping in oil too, but a K&N is very oily. They're supposed to be. The oil gets the very fine particles to stick to it instead of passing through the foam. On some cars that use a Mass Air Flow sensor, this air filter oil contaminates the sensor wire in no time at all. This of course causes driveability problems. Specifically on an MDX, this oil can build up in the throttle body and Idle Air Control (already something prone to failure on the '01-02 MDX) and cause problems. My professional advice on K&N? Don't do it. Stick with the Honda filter and replace it every 30k. |
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| cfarm |
quote:
Originally posted by SuperTech
The MDX uses heated O2 sensors. It's capable of going into closed loop condition as early as a couple minutes after you start up cold and drive off.
What you read on the other forum is correct...but in relation to this modification, it isn't. So fuel trim is controlled by the O2 sensors in closed loop. However, at wide open throttle, the system goes back to open loop. And horsepower (such as a gain from making this modification) would be measured at wide open throttle. In open loop, the computer determines fuel and spark curves based on readings from the Intake Air Temperature sensor among a host of other sensors.
Maybe it's different on the MDX, but I thought all OBD-II stuff reads from fixed tables at WOT, with offsets for IAT, coolant temp, battery temp(not kidding) and a couple of others that don't come to mind right now.
Problem with these overpriced Ebay rheostats is that the computer technology of today has quite good adaptive AI designed into it and the effectiveness of the device is all but lost after just a couple of drive cycles. |
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| 93springer |
Supertech,
Thanks...I think you are saving me a lot of money and unnecessary aggravation.
93Springer |
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| SuperTech |
quote:
Originally posted by cfarm
Maybe it's different on the MDX, but I thought all OBD-II stuff reads from fixed tables at WOT, with offsets for IAT, coolant temp, battery temp(not kidding) and a couple of others that don't come to mind right now.
I'm not into them that much to know (or care), but the computer has to be able to vary fuel and spark curves at any given time. Even at WOT. Suppose you're at full throttle and the engine starts to ping? Will the computer continue to follow its programmed "cell" (that's what GM used to call these set maps) and go ahead and let it ping till you burn a valve or put a hole in the piston? No, of course not. The computer will see the knock sensor reading and dial back timing and fuel till it stops. Even at cruise, there is no fixed table. The O2 sensors determine long term and short term fuel trim. |
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| loa3 |
| Wow -- Cleaning and oiling an air filter! That's really what I want to do! I remember our 1957 Chevy -- had an oil bath air cleaner -- had to clean and re-oil it every 1000 miles. What a pain! My next car, a 1965 Chevelle had a paper air filter-- no cleaning and oiling -- what an improvement! Now, folks want to clean and oil an air filter??? I'll stick with the stock paper filter and enjoy modern technology. |
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| cfarm |
quote:
Originally posted by SuperTech
I'm not into them that much to know (or care), but the computer has to be able to vary fuel and spark curves at any given time. Even at WOT. Suppose you're at full throttle and the engine starts to ping? Will the computer continue to follow its programmed "cell" (that's what GM used to call these set maps) and go ahead and let it ping till you burn a valve or put a hole in the piston? No, of course not. The computer will see the knock sensor reading and dial back timing and fuel till it stops. Even at cruise, there is no fixed table. The O2 sensors determine long term and short term fuel trim.
Except that many of the Detroit built products still don't have knock sensors (-; They do burn pistons or pop head gaskets, but most engine designs today are capable of withstanding moderate detonation before self destructing.
There are definitely many "table based" fuel and spark maps, both factory and aftermarket. Think of them like spreadsheets where cells are read for fuel injector firing duration and spark advance. The values for the different axis is determined by which table you're reading. |
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