NCT Failure HELP!!

[waynebowden]

Hey Guys,

Spent the last few weeks and as you can see by most of my posts a lot of work and money getting the GR NCT ready.

On the drive way this morning just as I had the car idling to warm up before the 100km round journey to have the car tested it started to hunt on the idle.

With time against me I was hoping if I arrived with a hot engine and left running pre test I would get away with it.

But on the drive up the car started acting really funny.

It was near impossible to maintain a steady speed the car would accelerate fine but when trying to hold the speed steady in low reves the car was almost chugging until the 3,000 rpm when is started to build speed.

I sent it through and I passed on all accounts except the emission were not tested as the tester could not maintain a steady rev between 2,000 and 3,000

I tested this after and I totally agree the car will rev to 2.000 just fine and past 3,000 just fine and a steady rev can be held in this range.

But when trying to hold the rev between 2,000 and 3,000 it’s erratic. The car build to 2,500 then drops to 2,000 while the foot is steady on the accelerator its jumps up and down and up and down and if you let off the accelerator as its building to 2,500 the car drops out completely and cuts out.

I will follow with a fail sheet and a video link of the crazy revving when I get home from work.

My local indie mechanic took a quick look over and advised he has never seen a car do this before.

SO please help

Thanks as always

Wayne

[brccrx]

http://youtu.be/8_kAkT3onw8

[waynebowden]

Thanks Seb,

Will get a look after work, So sickened of all times to start acting up on the way to the test center.

On the bright side all else passed

Thanks Wayne

[waynebowden]

Hi Guys

Ran the diagnostic and getting code 13

A quick google has pointed to the: Intake air temperature sensor

Any one have experience with this?

Or can point to the sensor location for a quick clean to see if this is a simple fix?

Thank you

Wayne

[brccrx]

Sensor is most likely located on the timing belt side of intake manifold, in the spot where 3 plugs meet, its the one that has finger push clip securing it not the matal tiny piece stoping it from coming of by itself if ya get me.

[waynebowden]

Hey Guys

Both myself and my indie mechanic are having trouble locating the IAT sensor, Can any one help?

Its a 1994 GR, google and forum searches seem to be pulling me from pillar to post with location and details

Can any one provide a picture of the exact location in a GR engine?

Thank you

Wayne

[waynebowden]

Okay so from what I gathered trawling through google for info on the GR IAT location it seems to be located within the mass air flow.

What I have done so far to no avail is:

Changed the IFS over

Patched a blow in the flexi on the down pipe

Changed the MAF from a functioning GX

And still tha car is hunting on the idle and immposible to maintain speed, Acceleartion is fine but maitining a steady rev or speed is impossible.

Any Idea's guys?

Thank you

Wayne

[optical illusion]

Hardly be the stepper motor needing a clean would it?

[waynebowden]

Stepper is the next item on my list.

I changed the TPS sensor and this rectified the maintaining of speed and the dropping of revs between 2000 and 3000 rev's

But the hunting at idle is now more prominent.

Do any of you guys have a picture where the stepper is in a GR engine?

I can find lots of guides for cleaning etc but none seem to detail removing the motor from the engine

Thank you

Wayne

[goz_83]

When looking into engine bay, look at top right of plenum and the stepper is just below the air intake. You should be a able to find an image on google and likely here on the forum.

[brccrx]

Did ye lads set the TPS as it should be?

[waynebowden]

Hi Seb,

No I did no configeration, just reset the ecu after fitting the tps, and after this the speed is good and the car can hold a rev between 2000 and 3000.

Its just the damn ideling causing a problem, but stepper motor is the next thing I will be checking can I confirm its the brown housing below the air intake on the manifold?

Thank you

Wayne

[waynebowden]

Hello Guys,

I think I have narrowed the stepper location down to 2 places.

I have taken pictures of the engine bay on my newly acquired GX.

It it either the small device shown below to the left of air feed.



Or the device with a brown housing located below the air feed, due to the awkward position of the device I was only able to catch a corner of it.



Thank you

Wayne

[brccrx]

Top pic shows TPS (this make me wonderiong what did You replace calling it TPS? )

Bottom pic shows small bit of the step motor. Best way to check it is in the morning when You turn the keys on before You start the car listen to clickling noise, anything? This will work only if the TPS its set as it should!!!

Not many people knows but the TPS sensor has one circut for throttle position and separate circut for idle control valve switch (the step motor) meaning that if the TPS if set wrong it might confuse ECU that the ICV shouldnt take control over the idle while it should if ya get me? Or if its only on the edge of adjustment point it will once controll the step motor and other moment it wont. U should really look in to this first just to make sure U not trying to find something thats not there

Im not sure is the top two or bottom two pins is the ICV switch but heres an idea how to set it on other mitsis and if You have no luck i'll check FTO TPS how to set it using multimeeter:

http://www.youtube.com/watch?v=HVeCWEwmBuA

And heres TPS set right:

http://www.youtube.com/watch?v=g9lUs1YJxSc

[waynebowden]

Hello Guys

Okay was up at the crack of dawn to work on the FTO.

I changed the stepper motor and disassembled and cleaned prior to fitting in to the GR.

With the air intake stripped off and the battery out to allow for more room and aid in a ECU reset apart from rusted bolts its was a pretty easy job.

But alas the car still seems to be coughing slightly at idle.

I have taken a few videos to support this, any help would be great

https://www.youtube.com/watch?v=47_kIXs ... e=youtu.be

and

https://www.youtube.com/watch?v=WLjWZlF ... e=youtu.be

I also followed to the best of my knowledge the TPS calibration

With all the above mentioned components removed I attached the multimeter to pins 3 and 4 of the TPS sensor( which were the pins that the value changed on when the throttle was engaged)



I loosened the TPS so it moved freely on the body and reading the multimeter on the below setting



I moved the TPS to the left and the values rose and then to the right and the values started to drop to a point and at the very extreme of the right started to rise again.

So I moved back to the left until I got the lowest value until it started to rise again

The lowest value I could get was 036



I then tightened the TPS back to the body and assembled all other parts.

The car started but the Videos above were taken after the TPS calibration and the slight hunt/cough of the engine is still present.

But on the plus side the engine error code 13 is no longer present.

Again any help, ideas or guidance would be great

Thank you

Wayne

[brccrx]

Could You please do a picture of the curent location that the TPS is set at.

Also run the engine and play with the TPS again to see will that make any even slight change.

[waynebowden]

Hi Seb,

Have pictures of the current TPS set up

From far back





Close up on TPS





and a top view of the setting



I followed the setting as best I could

In your youtube video Seb you have the multimeter on the diode setting from What I can see is that correct?

And am i correct in trying to obtain the lowest value before it starts raising again?

Will get a chance to alter the settings tomorrow evening

Thank you

[brccrx]

No, U just turn it up till ya get the meeter to bip as on my movie.

I'll do some pics of the tps ive on my red Fto and post it on here, so U might just copy that to make Your life easier.

[waynebowden]

Thanks Seb

My multimeter doesent actually have a beep on the diode setting could you check yours on the ohms setting as it is now running fine and let me know for refrence?

Thank you

Test is thursday so time aint on my side

Wayne

[brccrx]

Sorry been busy all day but iove promised ya the piocs so there ya go









The ohm function wont do much good here, just copy the setings that on mine and see how would she run, might be the case that the TPS is knackered?

Take it off completely hold it close to Your ear and turn the butterfly over slowly, any kind of rubbing noise from the inside of it when U have turn it about 5-10-15 mm from the begining?