EvoKevinEvo

hi guys, 1st post here sorry for the length. I got an 03 evo8 4 months ago, completely stock.i fell in love, car ran awsome. shortly after getting it i put in a tb 3" catless exaust, o2 housing, header, fmic, and a mbc. I drove it this way for a while, i took it to the dyno and got impressive gains. Unfortuneatly i got knock the last pulls to tweak the tune and it ended up being a rod bearing. The tune was almost "dialed in" what my tuner told me.

I pulled that engine and im currently building a 2.3L from that core, I installed a junkyard 2005 with 40 k miles. The only difference is the 10.5 turbo vs 9.8. The car runs and drives great when you drive like my mother. When you harp on it and it goes into boost the cel flashes indicating at least 4 counts of knock, it is also running richer than 10:1 cuz my afr gauge is burried rich. Thinking this could be a problem with the tune i went back to the dyno and had them re install the factory tune. the afr got richer, and i cant check for knock anymore. When you harp on it now and hold it for a few seconds it will make a POP noise and the car jerks like it lost all power and the afr instantly pegs lean when this happens. Correct me if im wrong but this is "fuel cut" right?

The STFT is all over the place even during idle and low throttle. I am thoroughly confused as well as my subaru mechanic buddy. I pulled the silicone connector off the turbo outlet pipe and pressurized my piping and intake man., it all seems leak free except a small hissing comming from the valve cover, you can tell by taking the oil cap off. I checked the vac. llines in back for leaks. not knowing which direction to take from here, i pulled off the blown engine and installed ign. coils, wires, fpr, map sensor, throttle body with tps and iac, i pulled the maf and cleaned it with MAF cleaner, replaced spark plugs with new. The problem remains.

I still drive this car daily, just cant go fast, it depressing me because it is much slower than it was when i got it and my mpg is tanking.
I ask for your help evo community, and ideas or advise is greatly appreciated.

grillpt

iTrader: (24)

My advise is to a professional tune the car properly. If you think there is other issue's with the car it can't hurt to have a reputable shop look it over (probably the same place that's gonna tune it). I don't know who's close to you, but I would think AMS would be within a couple of hrs?

milford

iTrader: (18)

Sounds to me like you need a proper tune for the current set up.

Evoixjohn

iTrader: (15)

AMS PERFORMANCE! You will be satisfy with them,It all depends how you want the tune to be (conservative tune,race gas,etc) Good luck with your car

EvoKevinEvo

ihave the car restored back to stock minus the exaust, boost pressure is at 19 psi. The factory tune was restored. could the tune really be that far off at this point?

EvoKevinEvo

c'mon guys, this is not a tuning issue. The car ran great with this setup before i put this new engine in. i never asked who you recomend to diagnose (which happens to be 6 hours away). I have worked full time all my life repairing cars, this is a diy and i asked advise based on evo experience....

what causes "fuel cut"

Evoixjohn

iTrader: (15)

Bad spark plugs,fuel pump etc

06RedRalli

iTrader: (49)

Is the car on stock injectors?

clubEVO93

iTrader: (8)

+1 with the professional tune. They see cars like ours everyday. They will be able to get to the root of the problem faster then we can. We arent around to look at it in person. Which could make a worlds difference. Considering the problems you are explaining to us over the forum. It could be numerous things. How close are you located to MAP? Go get some dyno time and see what the chart looks like. Make sure everything checks out. Well its obvisouly not. So I think that should be your next step before you really damage your car bro. Things break and mileage suffers with a bad tune.

EvoKevinEvo

ok, i was driving the while car checking obd live data. unfortuneatly i saw no sensor readings that sparked alarm, fuel trim was all over though. More unfortuneatly while diagnosing, i went wot and the car chugged, and killed.

notes

-the afr went pegged lean at the same time it killed

-noticed the tach in dash read 0 rpm while coasting 70 mph in gear after engine killed with key in run

-engine ran good right up to when it bucked and suddenly killed

-cold as hell next few days, working overtime currently, this really sucks

-please suggest ideas crank sensor, fuel pump etc. i have a feeling this is related to my previous problemso this is not alllll bad stuff that it died

EvoKevinEvo

also while bearing the elements i checked that the cams spun while cranking, they do. i will get the car home to my heated garage tommorow where i can get into it. im a wus when its 2 degrees and windy and dark. This is not a mechanical problem, what could cause a sudden stall like i described?

clubEVO93

iTrader: (8)

So its not a mechanical problem or a tune problem? I would start with the basic. Timing, Considering its a salavge motor?

EvoKevinEvo

I will be checking for spark tonight, my next oppertunity. The tach read 0 rpm so I have a feeling that there is no spark signal. to your guys experience what could be causing this. and how do I test crank n cam position sensoron our evos?

grillpt

iTrader: (24)

What sort of exhaust is on the car now? Cat-back, turbo-back?

chu

iTrader: (72)

This should be reposted in the ECUFlash section for better answers!!