AirBez

Hey guys
Got an issue with my Evo7.
The idle is sometimes high and sometimes its low, it feels like its going to stall when I come to a stop and other days it will jump up to 1500rpm.
Also when this is happening I get a fair bit of bucking around 2000rpm, so when coming out of corners etc. The car feels fine above 3000rpm.

The strange thing is that these problems come and go, one week the car will feel perfect and then all of a sudden it will run crap for a couple weeks and then it goes away again.

I have done a boost leak test and its fine.
I have replaced the IACV with a new one (car ran perfect afterwards but problem came back)

I had a P0120 code (tps sensor) which I cleared and it didnt come back for about 4 months, even though the car had issues during that period.

Any ideas guys ?
I don't understand why the problem comes and goes.

Thanks

Bhsj13

MAF, MAP? how is fuel pressure? how old are coils?

AirBez

MAP
Haven't checked fuel pressure. Its running a walbro 255 and id1300's.
Coils would be original, car has 69,000kms.. (probly wound back)

Bhsj13

probably your maf sensor going out. my maf and map sensors started going out around 90k miles and it was similar to yours, my fuel pump sock filter was also dirty. replaced all and it was fine after. do you have a buddy who you can swap a maf sensor to see what it does?

AirBez

No maf sensor
Its speed density setup.

Bhsj13

maybe the MAP sensor going bad?

4b11slayer

In a techs look at things. I would replace that tps and recalibrate it (if applicable) idk if they are fixed or require back probing and looking for certain volts at closed throttle.

Even if its not setting a code now id still do it because those are symptoms from a bad tps.

AirBez

Hooked up a obd2 today and monitored the tps.
During idle with a closed throttle the revs were jumping up to 1500rpm and then back down. The obd2 was reading tps 87.1% then back to 0 with the rpm jumps.

Is this a good indercator that the tps is playing up ?

4b11slayer

Idle jumping up and down usually idle air control fault.

As for tps my current data is 14.9 volts at idle

AirBez

IACV has been changed, problem went away but came back the next day.

Would a faulty IACV make the TPS reading jump up to 87% with a closed throttle.


I think I just need to replace the TPS and go from there.

4b11slayer

Replace the tps since it already set a code in past.

kbisson

Hello!
Im brand new here and rolling with my 2012 Ralliart
And now to business,
not trying to jack your tread or anything but I got a similar problem
I went to the dealer and there was 0 error codes however yesterday while driving in the city (regular driving) at a stop light the engine's rpm was jumping from 600-1500 rpm in a 3 second interval. I got scared and pressed on the gaz a little bit and to get some fuel in there and the problem went away. but im still worried that this might be the beginning of something. (I would like to up the idle rpm by 50 rpm to 800rpm but i do not know how or have the equipment.....)

Ferp

You would have better luck posting this in the Ralliart or even the Evo X sub forums.