Problem i cant get to the bottom off.. collective thinking needed lol

[HYBRID]

Problem with DC is its always looking for a path back to earth. The ecu gives out a 5 volt positive signal to the sensor, but the 5 volts would not be read by the ecu interior components, until the components are connected to earth, creating a path.

So if the wire that is carrying the 5 volts back to the ecu gets shorted to earth, the 5 volts never gets to the ecu, it has got to earth at the short.

The IAT sensor is a big resistor, like the water temp sensor, its resistance decreases as temperature increases, if you disconnect it , it just thinks the air temp is high, so it does not adjust fuelling as much as it would if it thought the temp was low.


You can replace it with a fixed resistance for test purposes, I think its max resistance is 2k ohms.

i see.. so basically unless i get another sensor & compare notes i wont really know.. what do u think about the ecu not showing the check engine when the sensor is not clipped to the harness? surely if it works like the water temp sensor then when unpluged the ecu should show some kind of warning? its also listed in toyota's error codes..

one thing i noticed today was i have an old pivot earthing kit (seen better days) & one of the earths broke off.. since then i was getting readings of 13.6v max.. which isnt very good.. i fixed the lead & to my surprise the voltage on the battery increased to 14.0v car is working better, albeit its still leaning out..

iv asked keith to pass me on an apexi earthing kit he has, as i think its time to retire the pivot wireing.. i can run much more earths & will add 2 more places... an earth from the body to the plenum where the inejctor earth wire is.. & one as u suggested to the turbo.. as well as 6 other lines

how can i know when the iat sensor works john? should i just try a new one & see if it changes anything? or shall i have a look at the earthing from the ecu to the sensor? perhaps run new lines?

kon

 

[weeJohn]

You can measure the voltage from the iat sensor at the ecu kon.

Pins E2 and THA, should be between 0.5 and 3.4 volts.

You should get an engine fault up by removing the sensor plug, the ecu will think its gone open circuit, and show code 24 I think.

Check your wiring again dude, it may be a short somewhere.

 

[350ep70gr]

Any news about your prob Kon?

 

[HYBRID]

You can measure the voltage from the iat sensor at the ecu kon.

Pins E2 and THA, should be between 0.5 and 3.4 volts.

You should get an engine fault up by removing the sensor plug, the ecu will think its gone open circuit, and show code 24 I think.

Check your wiring again dude, it may be a short somewhere.

thats great news john! thanks will check it out mate! no im not getting any errors from the ecu when i unplug the sensor

will check & see what happens
kon

 

[HYBRID]

Any news about your prob Kon?

Im afraid not chris.

However im going to go over all my earths as iv noticed some things arent right..

voltage from my lambda sensor ony gives a max of 0.3v?! even on wot.. as i checked.. my blitz fatt turbo timer on auto mode should add seconds to the countdown depending on how long i drive for.. it doesnt anymore .. & my voltage on the voltmeter whilst car is running never goes over 13.8v.. so i may have either a short somewhere or an earth gone wrong.. or something else which could be related to all the problems im having.. maybe its the ecu.. but i doubt that would alter the sensor readings...

i need a favour from somebody with an ep91.. can you pls unplug the iat for a second & tell me if the ecu dash light comes on? it would be a great help as mine doesnt

kon

 

[Sheldon]

Im afraid not chris.

However im going to go over all my earths as iv noticed some things arent right..

voltage from my lambda sensor ony gives a max of 0.3v?! even on wot.. as i checked.. my blitz fatt turbo timer on auto mode should add seconds to the countdown depending on how long i drive for.. it doesnt anymore .. & my voltage on the voltmeter whilst car is running never goes over 13.8v.. so i may have either a short somewhere or an earth gone wrong.. or something else which could be related to all the problems im having.. maybe its the ecu.. but i doubt that would alter the sensor readings...

i need a favour from somebody with an ep91.. can you pls unplug the iat for a second & tell me if the ecu dash light comes on? it would be a great help as mine doesnt

kon

can do if you tell me what plug i need to take off lol. also if you want you can come and take my ecu..

 

[HYBRID]

thanks sheldon that would be fantastic!!

ok look at the plenum, on the left there is a sensor with a dark grey clip, whilst the car is running unclip it, have a look at the dash & see if it flashes.. if it does than reclip it on & after a few seconds the light will vanish

thanks for the ecu as well, but let me see if i can solve it without changing the ecu 1st

tell me when u check ta bro

kon

 

[Sheldon]

thanks sheldon that would be fantastic!!

ok look at the plenum, on the left there is a sensor with a dark grey clip, whilst the car is running unclip it, have a look at the dash & see if it flashes.. if it does than reclip it on & after a few seconds the light will vanish

thanks for the ecu as well, but let me see if i can solve it without changing the ecu 1st

tell me when u check ta bro

kon

well today im at work.. so if im not tired i will do that after work at 10:30 maybe? or tomorow morning as tomorow im going to remove mani and turbo...

will i need to leave the car warm up orn no? if you get a pic up would be perfect ninsa wisq man u niprintjahha.

http://i94.photobucket.com/albums/l90/xeldin/CIMG0042.jpg

dak ta hdejn il vacume line li jmur ghal go DV?

 

[HYBRID]

hi bud yes thats the one, next to the bov vac line.. much appreciated shel!!

no u wont need to leave it warm up etc.. just unplug it at any point & see if the engine warning light comes on

many thanks!
kon

 

[Sheldon]

hi bud yes thats the one, next to the bov vac line.. much appreciated shel!!

no u wont need to leave it warm up etc.. just unplug it at any point & see if the engine warning light comes on

many thanks!
kon

no worries, if no light comes on il check for error codes also. will probably do it tomorow morning first thing.

off-topic - ghada jiftah ux chris ? halli nmur sandu forsi jiweldjali il manifold.

 

[HYBRID]

yes he will be open bro

if u have some time to check this morning it would be most appreciated

kon

 

[Sheldon]

yes he will be open bro

if u have some time to check this morning it would be most appreciated

kon

already did and also went at chris.

mela,

started the engine and took off that thing you told me and no engine managment light came on. switched of the car, did a diagnostics test and error 24 came up. (ATS) is that the same sensor??

 

[HYBRID]

24 is the code for the air intake temp sensor.. so yeah thats it .. strange how it didnt mark up though..

so i measured some stuff.. (this one is for weeJohn)

voltage whilst off (at sensor clip engine side) 0v
checked for continuity none found..

voltage whilst off (at sensor clip engine side) (4.98~5v)
once again no continuity

i tried to get a reading from the sensor, & when cold (ie engine off i get 0v) & when the engine is hot i get a lovely 0v again.. does this mean its not working or am i doing something wrong john?

what do u think about the results bud?

I installed an apexi power earth kit as to my surprise my old earthing kit was dead.. (wasnt getting any continuity from end to end lol) & also the factory main earth was buggered.. after i installed it to my amazment from 13.4 on the voltmeter im now getting a constant 14.5v!!! im like wow!! lol talk about much needed!! also checked for continuity & i have a perfectly earthed front end now..

thing is im going mad as the car is still leaning out.. (waaaaaaaaa!!!!!) so now im gonna try & borrow another ecu maybe i dunno by some slim chance its fucked.. iv got an iat sensor on the way (many thanks to Darren Burwash!!) & i have another lambda sensor on the way (many thanks to the legend that is Jay!!) will change them (AGAIN!!) & see what happens..

many thanks to everybody for trying to help out!!
kon

 

[Sheldon]

if you want you can come and take my ecu.. at the moment the glanza is without turbo and mani.. i dont think i would finish it for saturday so if you want you can use mine. aqla u wahal int imma!!

 

[Texx]

voltage whilst off (at sensor clip engine side) 0v
checked for continuity none found..

voltage whilst off (at sensor clip engine side) (4.98~5v)
once again no continuity

How are you measuring the voltage? I'm presuming your measuring from body ground to each of the IAT harness connector pins individually? If so, the above voltage readings look good, 5v ECM reference feed and 0v sensor ground.

Have you measured the voltage between the 2 harness pins with IGN on and connector disconnected? Does it also read 5v?

Where are you measuring continuity to and from?

 

[HYBRID]

if you want you can come and take my ecu.. at the moment the glanza is without turbo and mani.. i dont think i would finish it for saturday so if you want you can use mine. aqla u wahal int imma!!

Thanks very much shel, issa nara, if ill need ill call u ta

thank u very much!!

kon

 

[HYBRID]

hi Texx, When i got the 5v reading from the clip, what i did was i put the multimeter to read a scale from 0 to 20v.. connected the earth pin to the earth on the clip & the power pin to the clip sensor reading.. ie from the clip itself.. i also checked to see if the clip had some sort of continuity to earth from the signal wire (black & lime) & it didnt, this is on the sensor side.. the sensor itself DID NOT give me any readings if hot or cold it still have no sign of voltage..

IGN on i always get a 5v reading from the sensor clip, off i get 0..

When i was checking for continuity i was checking from the neg terminal & the other to the end point of the earths.. it was mearly to get some decent earthing going on.. but it really did help stabalise my current thats for sure..

kon

 

[Texx]

hi Texx, When i got the 5v reading from the clip, what i did was i put the multimeter to read a scale from 0 to 20v.. connected the earth pin to the earth on the clip & the power pin to the clip sensor reading.. ie from the clip itself.. i also checked to see if the clip had some sort of continuity to earth from the signal wire (black & lime) & it didnt, this is on the sensor side.. the sensor itself DID NOT give me any readings if hot or cold it still have no sign of voltage..

IGN on i always get a 5v reading from the sensor clip, off i get 0..

When i was checking for continuity i was checking from the neg terminal & the other to the end point of the earths.. it was mearly to get some decent earthing going on.. but it really did help stabalise my current thats for sure..

kon

Is the E2 sensor ground terminal making a good connection at the ECU. The resistance from an intermittent poor ground would cause a corresponding voltage drop across all sensors grounded at that terminal.

 

[HYBRID]

i cant manage to get a reading from the ecu.. im sure im touching the connectors propperly, but for some reason whatever i touch with E1 its like its not there.. even though when i check for continuity on the earth i do get continuity.. so i suppose that the earth is fine.. im reading btw using E1 not E2.. could that make a difference texx?

kon

 

[Texx]

E1 grounds the ECU to the body I think and E2 grounds the senors to the ECU so it can measure the resistant withing each sensor circuit. It would be worth disconnecting both the IAT sensor connector and ECU 16 pin connector and then check the resistance between each IAT sensor connector pins and the 16 pin connector pin 3 (IAT ref feed wire) and pin 9 (E2 sensor ground).

You should have 0 resistance on both of these wires, any resistance found, particularly between E2 and the IAT sensor will cause a voltage drop.

Then check resistance again with IAT and 16 pin connector disconnected between the ECU 16 pin connector pins 3 and 9. This should be open circuit. If any resistance is found, then it would point to a short in the wire harness between those two wires.

If your readings are as expected, then either there is no fault with the IAT sensor circuit, or you have a faulty ECU or sensor, although it does seem odd that the ECU doesn't store a code when the IAT sensor is disconnected. That would say to me either the ECU is faulty, or you have a short in the harness between the IAT sensor ref feed and E2 sensor ground which leaves a resistance in the circuit after the sensor is disconnected.

I still think the cause of the fault you are experiencing is due to something the ECU can't detect or measure causing and incorrect adjustment by the ECU resulting in a lean burn. That's why I suggested a mechanical fault with an injector. Theres not much than can trick the ECU into running as lean as you describe, more often than not for safety reasons the ECU will fuel quite rich when it detects a fault or unexpected sensor reading.