| From | Message |
PETE
Dodge Dakota
JOIN HERE
4/03/2007
09:50:05
|
 Subject: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
Anyone, LARRY ? Have a chart or a spec for INTAKE AIR TEMPERATURE SENSOR (IAT) need the resistance parameters my one book Haynes Manual that does'nt really give me a true resistance values, these manuals are not true enough for our sensitive sensors . I had a spreadsheet for this but i tossed to the curb not knowing i did. I look at many posts here and everyone wants to relocate this sensor to fake out for more power which is great. I'am dealing 2002 with a 3.9L Vin "X" for motor & Multipoint Fuel Injection.
|
PETE
Dodge Dakota
JOIN HERE
4/03/2007
22:39:33
|  RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
I Can't believe theres no mechanic like myself no to be considing myself as being perfect by any means just need some more info on this sensor other than the info in this HAYNES manual which I don't feel comfortable with troubleshooting with. Again I don't want come off as a d!ckhead mechanic, I no longer work in the garage so i lost alot good info i had at my fingertips and no longer thanks to my old fart boss going out of business so now I do my repairs for freinds,family etc. on the side when asked for help now i'am stumped with this problem to solve before I changed this no so cheap sensor.
|
Forseti
Dodge Dakota
JOIN HERE
4/04/2007
18:42:31
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
The IAT is nothing more than a simple thermistor ...... do a search on the net for thermistor values .... what problems are you having? what are you trying to figure out using thermistor values ?
|
PETE
Dodge Dakota
JOIN HERE
4/04/2007
21:36:49
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
Forseti, I understand that I'am dealing with a variable changing resistor with temperature changes in the intake to adjust our air/fuel, when I ring out my readings with my digital ohm meter they are off the wall from what this manual HAYNES is saying and I would think it would trip my MIL lamp(CHECK ENGINE LIGHT). What I'am experiencing is my gas mileage week to week to change I have kept my maintenance up to par for the last 5 yrs I've own the truck since new and put only the best quality parts or sometimes even OEM if needed , 02's were change this last complete tune up because mileage approaching 70,000 had gone through everything and this sensor is doubting myself whether to swap it out with a new one was wondering what LARRY what would do . I do appreciate the advice and again I don't want come off as that d!ckhead towards you or anyone else that might help me. I don't trust these published manuals for our trucks they are not detailed enough for the in depth mechanic and I do have close freinds at dealerships but getting mixed thoughts on it as well. I don't want to be one those just start replacing parts to cure just have the $$$ and time .
|
PETE
Dodge Dakota
JOIN HERE
4/05/2007
10:25:45
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
Also want to add to this bothering sensor values, what throws these sensors out of there resistance values before they trip MIL lamp considering mine and no light. I seems to be intermetent problem but don't want any chaos later to screw any other sensors which could add too $$$.
|
Forseti
Dodge Dakota
JOIN HERE
4/05/2007
16:33:49
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
Think about this ...... how is the PCM going to know that the resistance values are out of spec ? If the IAT sensor tells the PCM the intake air is 110 when its really 80 how would the PCM know its wrong if thats the ONLY sensor the PCM has to go by. As far as I know the only thing that would trip the MIL for a IAT sensor is if the value drops way below 2K or it reads open short .... here are the sensor values according to my book....
32deg. 29,000 to 35,000 ohms
50deg. 17,990 to 21,810 ohms
68deg. 11,370 to 13,610 ohms
77deg. 9,120 to 10,880 ohms
86deg. 7,370 to 8,750 ohms
104deg. 4,900 to 5,750 ohms
you need to pull the sensor out set it on a table in your house for like 10 min then check your A/C controls IF you have a digital readout or measure the ambient air in your house ... then check your IAT resistance values according to the chart....
|
J and J Auto
GenII
 
4/06/2007
00:52:57
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
reading under 50 degrees will trip the mil
or over 250
The IAT and the engine temp sensor run the same
values ohms to temp
set it out for 10 min check now put it in your
arm pit for 5 to 10 and check it again should be
around 100 if your fast enough LOL
a quick easy check with a digital ohm meter like
this will tell you if its working properly
15 to 20 degree max if more than that replace it
You can also use a scanner check cold, now start
engine and watch it
in the intake cold it should read same as outside
air temp when engine is at op temp 180 to 200
at idle will cool down while crusing
locating this 6" from throttle body in bottom of
air cleaner or tube it will read 90 to 120 this
is the optimal location and temp to run
reading colder it will advance timing and increase
injector pulse width more hp and torque 5 to 10hp
gains can be had here as long as all sensors are
good especialy the o2 if the o2 is lazy you will
see no gains and some will even run worse
A lot of the guys running nitrious set this at
a steady 75 degree with a resistor and a scanner
and its always there at 75
relocating this in the optamal position will give
the comp a more realistic reading of the actual
air temp entering the motor better throttle
response and a slightly fatter air/fuel ratio
Larry
J&J Auto
|
PETE
Dodge Dakota
JOIN HERE
4/06/2007
12:40:06
|  RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
Hey FORSETI and LARRY thanks for your help did'nt get chance to look at it till now which is 12'ish FRIDAY. When I took it out of the manifold I was suprise to see what I've found out ?? The sensor itself was wet like a flooded out spark plug after trying to start a 2 cycle weed wacker with the wrong gas/oil ratio mix LOL ,Ive never come across this before in my days of being mechanic. But far as ringing it out with my OHM meter after I clean it up and let it set at room temp. according to my digital thermostat i put in to help with our heat bills LOL says "68" and resistance reading 11,370 ohms and fluctation as I touch or move it , so I put by my heat register when the heat kick on sensor responding well to change all within specs. you gave me, so this tells me i dont have a sh!t sensor because I did the hair dryer as well responding well. Whats up with the wetness I don't recall ever seeing this ?? . And might consider what you said LARRY might relocate ?? Is that normal or should I keep digging to find out why its getting wet ?? THANKS AGAIN to Forseti and to you LARRY If you have anymore advice would be helpful to solve this mystery and close the book so I can continue my happy TRUCKIN' and helping my other TRUCKIN buddies out.
|
????
Dodge Dakota
JOIN HERE
4/07/2007
17:41:35
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
was it oil or gas ???
|
PETE
Dodge Dakota
JOIN HERE
4/07/2007
18:32:14
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
GAS!!!
|
J and J Auto
GenII
4/08/2007
03:00:34
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
did you just start it cold and run a little and
remove it
no it should not wet with gas
should be dry with just a little residue on it
from the pcv line just a dark shading
sounds like you have some other issues there
are your plugs black running to rich
it would have maybe a gas smell but not wet
If you relocate be sure you put a 1/8 npt plug
in the hole
As I said the engine temp sensor same resistance
2 wire down by thermo housing if reading cold will
make it run rich but if it was reading under 170
it would trip a code
TPS or o2
tps center wire and ground should be between
.3 .7 with .75 optimal key on engine off open
and close throttle and it should always return
to same low volts
1 other thing I am thinking is a pluged cat that
would back up into intake and it would be wet
does it run like crap
Larry
J&J Auto
|
PETE
Dodge Dakota
JOIN HERE
4/08/2007
17:05:49
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
No, truck set all night till I pulled it out and being wet, and truck running good before tune up and after only thing I did this time I changed my 02's cause thought i was time 70,000 approaching and also flushed my radiator and dropped a new thermostat in . My plugs light grey to white old ones came out when I pulled out new ones same with about 3 or 4,000 miles on them now.I would think the truck would be runnning like sh!t to but its not. The old 02's had nothing on them other very little carbon on them. Also have good vacuum. Like everyone that complains including myself to the club, mileage was good than dropped off dramatically has not came back to where it should be like your getting LARRY . Would like to inspect my plugs again and see my finds. Also never had my MIL lamp come on before or now. I did clean my IAC when I did the tuneup like every other tuneup i've done twice before and still got great mileage until now. This is why iam inspecting and checking everything out before Sh!t hits the fan.
|
PETE
Dodge Dakota
JOIN HERE
4/10/2007
13:51:41
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
Well finished up some more invisgated my issues i'am having after i checked my IAT sensor the first time I found it to be wet so I cleaned it up and checked it to be good and responding within specs, so I turned to TPS sensor and found to be good too voltage .57 at closed throttle and WOT to be 3.5 volts so is to be good, or should I be getting 4.5 volts max. like my info. I have at hand . And reinspected my plugs still white to light tan , feel that I might be running a little lean ,wish I had better tester to watch my 02's switch , my volt meter shows they are within but rather see them on scope no avaiablity because no longer in the field just on the side for $$ as needed.I do notice lately lot trucks like ours tail pipes seem to be black and sooty mine like brand new think I'am having fuel pressure issue ?? And also checked IAT sensor this time to be like you were saying LARRY like your PCV valve happy to see that. Enough my babble still stumped to see my mileage being were it is and where it was
|
J and J Auto
GenII
4/11/2007
21:52:17
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
where did you get the o2 sensors and what brand
were they
The bosch sold by auto zone and most parts
houses are junk if you have these get rid of them
ngk.com the ngk ntk same as factory uses for
half the price cubic zarconion this is the right
sensor
Have you ever checked injector sync
turn engine clockwise only put vibration damper
on TDC top dead center rotor aiming at or near #1
plug wire also marked on cap if not aiming at #1
go around again
use a good light be sure the line and 0 on the
damper are lined do not turn back if you over
shoot go around clockwise again
now look down over rotor the rotor button
there is a line on the dist pickup plate marked
cyl
0 the rotor button will be centered on this line
looking from front the back of rotor button lined
with this line is +3 it should be 0 to +3 that
is where they run the best
The dealers set them anywhere between 0 to -6
getting this on the + side will increase throttle
response and improve gas mileage
1/2 bolt on dist losten to turn
clockwise moves toward -
counter clockwise towards +
All the dist does besides distrubting the spark
is tell the injector when to fire
The intake valve opens at 8 before tdc at 0 the
valve has been open for 8 degrees already open
very little at +3 open farther and pulling fuel
into the cyl better
if you go behond +8 it will trip a code for
injector sync I like to set them from +3 to +6
the valve will have been opened for 11 to 14
degrees and open farther taking fuel faster
when open farther
Your IAT being wet after sitting over night may
just have been condinsation if it looks ok
pulling it after running your ok
oh be sure to push back counter clockwise lightly
on the rotor when checking this it will remove
any play than check
Larry
J&J Auto
|
PETE
Dodge Dakota
JOIN HERE
4/12/2007
21:32:53
| RE: IAT SENSOR SPECS(INTAKE AIR TEMP. SENSOR
IP: Logged
Message:
Larry thanks for getting back with me, spent the day at my buddies changing out ignition tumbler in a 89' FORD Taurus,he misplaced his keys when he went out his date guess he had better things on his mine LOL. As for my 02's they are NTK OEM was able to get them at dealer cost from freind service advisor manager for dealership down the road. As for the injector sync. I did check this about when truck had about 40,000 miles (second tuneup) things were from they were set when truck rolled off the assembly line a smidging ahead of the cyl. index if I recall but that was couple yrs.ago not exact I don't think it would move that much in 20,000 + miles??. My buddy had shown me a 95 or so Dodge Intripid asking me my insights of this but could'nt get to look at it was at used lot 1 owner says on window , I know this would be better than 309,000 mile 89'Taurus I told him., put your keys on the table and other tools in her tool box LOL. think its worth checking injector sync 20+ miles later? And this tuneup put factory champions in was a freeby by buddy at the time visting see if they had any extra work that I could get for cash. Iam wondering if I should drop 8,000 miles on those champions and swap them for NGK FR5's feeling bit lazy after helping my buddy out plus been working all silly hrs. this week everyone on vacation but me. LOL
|
| | P 1 |
|
Post a reply to this message:
Username Registration: Optional
All visitors are allowed to post messages
|
