tsitalon1

iTrader: (3)

Hey guys,

While fine tuning my Boost, I noticed that my A/F is now leaner than it used to be. Unfortunately I never logged IPW or IDC before so I don't have a baseline to compare to.

I wanted my A/F to be around 11.5 at peak and taper to 11.0 at redline. I have now had to richen the hell out of the maps to get it close. My mods are in my signature so please refer to it.

Things I have checked/replaced:

1. FPR vacumn hose IS connected and secured (has been for months)
2. FP Relay has been replaced to newer style months ago.
3. LTFT idle is -1.X
4. LTFT Cruise id +3.x

I am seeing >114% IDC at 7k with my few mods.

It is important to note that temps are around 35º and the cat-back is a new addition. From my looking around 210load around 7k doesn't seem that abnormal for a stock turbo EvoX. Anyone else seeing these load levels around 7k with a similar setup?

Any other suggestions?

Logs and Fuel map to follow shortly.....

tsitalon1

iTrader: (3)

Data below

tephra

iTrader: (6)

if your richening your map and no change is AFR is being observed then either:

a) your injectors are maxed
b) your fuel system (think fuel pump) is maxed out

Since your IDC is 115% it looks like your injectors are maxed out.

I would lean out the fuel map AFR until it starts to actually go lean, then recheck your IDC. if its above 95% then you need bigger injectors.

if you can get it below 95% and there is still no change in AFR then you need a new fuel pump.

tsitalon1

iTrader: (3)

Tephra,

This is exactly what I thought, but how can this be possible on a stock Evo X with my mods? At what load level do people start pushing the limits of the stock pump at 7000-7500 rpm?

I thought our pumps had more overhead than that.

tephra

iTrader: (6)

TBH I don't know how good the X pumps are.

Evo VIII pumps used to be terrible, IX were pretty good upto 220kw, I have seen X injectors + pumps ok upto 230kw (all at the wheels)

What AFR are you recording at the moment?

IMHO you want it richer down low - ie 11.0 at peak and leaner up top (11.5).

tephra

iTrader: (6)

for what its worth, on my car (stock except for tune + 3port + wideband)

at 7250 RPM I hit 18.5 psi, 18*, 205 load, 11.3AFR, 87% IDC

tsitalon1

iTrader: (3)

This makes me wonder if the new FP relay has gone bad......

I am slightly higher load (210) but much higher IDC...

tephra

iTrader: (6)

Well lean out the fuel map UNTIL you start seeing that actual AFR leaning out as well.

Then report back with your new IDC

Also from memory these pumps are low+hi voltage, so if it is locked in low voltage then it wont flow as much...

Lastly - have you filled up recently? particularly from a station thats dodgey or was being refilled it self at the same time? You might have picked up some crap and its in the filter.. restricting flow..

good luck

tsitalon1

iTrader: (3)

Tephra, I will do some more aggressive logging this weekend as I will have a 4 day weekend.

I had some thoughts though, please hear me out.

I am concerned that I am running leaner than I want to be, however, I am more concerned about the 115% IDC.

Now, what drives IDC at WOT? To my knowledge it is Open loop - so - simply Load and Fuel map/injector scaling. My understanding is there is no feedback loop (at WOT) to even tell the ecu that a FP is failing.

So in my mind, if the FP or FP relay was failing, the ECU would not be aware enough to drive the IDC higher. It would simply keep the lower IDC's and you would see lean Wb02 readings.

I had the relay fail on me months ago and when it did I was seeing 12.5-13 a/f's. Currently I get as rich as 10.8(6000rpm) and then 11.4 or so at 7300.

Your thoughts on this?

tephra

iTrader: (6)

yeah thats correct.

but the problem is you dont have a baseline to work from..

which is why we need to work backwards ...

tsitalon1

iTrader: (3)

Can you help me understand why leaning out the fuel map will help diagnose the problem?

I would think it would only prove the ECU is doing it's job by looking at load/fuel map and injector scaling.

I think your initial guess - running out of injector may be the issue. Is that even possible at my level?

Just to re-cap 210 load at 7k at 300ft Altitude..

Hiboost

iTrader: (9)

600cc injectors shouldn't be at 100% duty cycle until 450 crank HP (~116 mph trap speeds).

tsitalon1

iTrader: (3)

I agree 100%, so what can drive them to 115% then?

tsitalon1

iTrader: (3)

Just a visual

Noize

iTrader: (24)

Every tuned + TBE X on the stock turbo I have seen does this: Goes leaner toward redline and the limiter. Its on the bubble of what the injectors can take.

IMO, Its not the pump in this case. Its also not the relay, or you would see much leaner AFR data.

If you're done modding, you'll be OK. If you plan to do more in the future, why not go ahead invest in some nice drop in injectors like the Deatschworks to lay groundwork. You'll be able to richen it up top with no issues then.

Tephra is far and away beyond anything I can share, but I've always fueling Evos mid 11s post full boost, then sort of holding that range, and richening up top like 6800+ to low 11s/high 10s for in-cylinder cooling. But I am old and am less concerned about power and more concerned about having an engine last. But with these mods, ~24psi tapering stock turbo, the stock injectors can't provide the fuel needed for that. Again, listen to people like Tephra/Bryan. They know these engines and how to properly tune them better than most anyone on here.