Hello! I have a problem with my Evo 8 that has started to run really rich mostly when its warmed up (about 11-12 AFR).
Im currently running this setup:
- Evo 9 10.5 20G Turbo
- Kelford 272 Intake & Exhaust cams
- Adjustable Cam gears
- Tomei fuel regulator
- Helix Organic Clutch
- Precision 780cc Injectors
- XS Downpipe
- Toyo Intercooler
- Japspeed race cooler
- Megan Racing Outlet Pipe
- Hks 3" cat-back 4,5 tums outlet
- HKS airflow kit
- DO 88 intake hose
- Daves Device boost controller
- IC Spray
- Walbro 255LPH pump
- RS diff kit
I also had the error code P0170 but it disappered after a while.

Its tuned with Ecuflash on 98 octane fuel.

Does someone possibly know what could be wrong?
I have done an boostleak test but it seems fine.

Sorry for my bad english, I'm Swedish.

Best Regards.

 

Probably a bad tune?
Or check for fuel pressure?
this can even be a bad MAP sensor

try cleaning the map,
then check for fuel pressure.
then check if u have any exhaust leak before the turbo.

atleast if those are all good, you can narrow down the list.

(I'm still a newbie also earning )

 

ive had the tuned checked and it all seemed to be ok, but i can post pictures of it here if it helps?
I have around 2.8 bar fuel pressure on idle. The car goes up to about 1500 idle and the afr goes down to 11 sometimes and then after a while it drops down to 1000 - 1100rpm and then it goes up to 1500 again..its not the same idle as it was before.. It's not that "wobwobwobwob" sound anymore,
i don't seem to have an map sensor on my intake so i can't check that
and theres no exhaust leaks before turbo.. I have run out of ideas now what it could be.. :/

but thank you for your reply!

 

Vaccum leak.

 

Monitor what the computer thinks the coolant temp is. If it's reading lower or much lower than it should it will run rich.

 

This happened to me on my previous built Evo, it definitely was not the tune and I could never figure it out but this happened when the car warms it idles at 11-12 and 1500 rpm


When I put on the A/C it would idle normally

 

Check for boost leaks first, then go from there.

 

Your idle fuel pressure at 2.8 bar (41 PSI) is 8 PSI too high.
That's compared to the proper spec.
In turn probably caused by flowing too much fuel (walbro pump) through an aftermarket low spec FPR (tomei).


The pressure might be creeping up because the voltage will be too.


A P0170 is a fuel trim failure.
So it might be just a failed oxygen sensor.
But they'll fail when they get all sooted up.
Because the fuel pressure is too high.
Or because it's tuned wrong because the pressure is too high.




There's 4 easy things to check.

Fuel trims with a data log.
02 sensor with volt meter.
Fuel pressure again.
Battery voltage.


But of course I could be completely wrong?