Ok people,

Here is a brain teaser for you.

2005 Evo with mods in Sig on Tephra Mod 7.

So car was running up to par and i was down on power and figured it was a boost leak. Found that the car had a line blown off on throttle body and then tightened down Forge BOV to prevent leak. I'm running 100% wastegate duty cycle on garrett 30r greddy profec B II controlled by the ecu which turns out to be 36lbs of boost.

While I was doing the boost leak test to 30-35 lbs i saw the boost leak tester stretch and it then blew off. I had all my leaks fixed anyways.

Now whether that had anything to do with it I'll leave up to you. Here is my problem.

My car would die every time with clutch in and rpms falling. It wouldn't catch itself. So I hooked up Evoscan.

Evoscan results:
Lows and Mids maxed out at -12.49.
Short Trims kept going to -25.

I figured after fixing my bov leak that I needed to rescale my injectors. They are currently scaled at 665 on E85.

AT 886 it still is pulling fuel. I thought maybe I had gotten some really bad fuel. Drained the tank all the way down and filled it back up. No Luck.

So Now what?

I used the return line to drain my tank and it flowed freely so fpr ok? injectors being clogged make it leaner? Boost Leak=Leaner at WOT

Get this at wot throttle no knock afr 11.0-11.3 which is a little rich but ok. Any idears ppl?

 

for e85 go for 11.8-12.0 .. i can run 11 flat and no knock, but it doesnt get you anywhere but horrible MPG.

Im just guessing, but did you disconnect the battery when doing the boost test to stop the double pumper from kicking on?

what does your fuel map look like? is it mostly 9, 10, 11's at high loads?

 

Ha. I've disconnected the battery like 4-5 times to get the fuel trims to reset b/c they kept sticking. When i had it tuned it was close to 11.8. I was just trying to say that it was def not a boost leak.

My afr's are all mid 12's on my fuel map.

I'm leaning towards a mechanical issue.... But i have no idea what.

You got any other ideas?

 

your fuel map shows all 12's ? that tells me your fuel trims are not right. And the fuel trims dont move? I think o2 sensor upfront needs changed maybe.

 

No. My fuel trims go crazy. I am going to check it bc it's reading so rich. I'm bout to do that now. My high octane my is tuned the way my car wants it. Tune is pretty much perfection. Lol

I'm going to change it to run in open loop only and see what happens. I'll keep you updated.

It's weird that "I'll pay someone to fix my idle" is kind of having the same problem. Lol.

 

Is your blow off valve running vent to atmosphere? Have you tried completely removing the BOV to test?

It sounds like normal VTA BOV issues - too much air venting / valve staying open causing uber rich to stall on lift off. You can often tighten up the aftermarket valves a lot and still have issues. Plum back often solves the issue.

 

LOL. ya but is your fuel map full of 12's? that is an indication the injector scaling is wrong.

I figured everyone knew how to use a biss, but i guess not. but from what i learned yesterday if your BISS is set out of range the ISCV will not beable to recover the rpm's and it will dip/stall etc.. The IAC is responsible for saving the idle and rpm from dropping to far and the ISCV is how it operates. If you just rev up with your ebrake up in driveway with the clutch in your car will stall? that is biss and target rpm etc.

fix the o2 sensor and fuel trims first tho, thats pretty important. the mid fuel trim will screw with your WOT tuning. Adjusting biss takes 2 seconds tho for a quick fix of the stalling issue & idle rpm neutral.

 

Thank you for the suggestions but my biss and my injector scalings were both correct before this problem. If you would have read the whole opening thread you would realized that this problem came up all of the sudden. I have been running my current map for months. So this leads me to believe that its going to be the front O2. I haven't checked it yet. Too busy

 

ya its the front o2. same thing happened to me before.