Lean AFR's up top.
 

Hey!

I wanted to see if anyone else could chime into this issue I've been dealing with.

So I recently upgraded my car with some mods and been running into some road blocks with enjoying this car. Its amazing when your car runs like crap how much you despise it when ur unable to figure out what the issue is.

Here are my issues:

- Sometimes when taking off, my car will almost sputter, AFR's will go dead lean, I'll have to back off the gas, get on it, clutch in, gas it and then take off.
- When going WOT, the AFR's will lean out to like 12-13's. The thing is, no knock, all other variables are fine.

Diagnostics completed:
- I checked the plugs, they are a bit black around the threads, showing some rich conditions however the tips themselves are completely fine, they are new.
- I have a non-cdi coil pack, took those out and put my stock... no change, reinstalled my non-cdi kit.
- My friend feels my AEM Uego Wideband sensor could be misreading, I did buy it used, so the sensor could be misreading, we did have a situation where when u turn the car to the 'on' position, it just kinda hovers and doesn't go lean, sometimes it doesn't mess up. So I think its very possible. I am picking up one up on Friday and installing it.
- A few ppl suggested maybe my front o2 sensor could be going. I gotta good deal on a replacement so I may just change is as a "JUST INCASE" kinda thing.
- I thought originally it was my walbro fuel pump so I swapped that with a new install kit, no change.

Only other things I can think of is Injectors, FPR and lastly tune????? The thing is, the stock FPR is good for high HP, Im trying to get 450-480 whp lol and the FIC injectors are brand new from MAP. Tune -- maybe? Seems like its fine so far.

I read other places about exhaust leaks however , I have a map o2 eliminator and its one piece so don't think so but maybe when we change the WB sensor I can look.

Any advice is appreciated, especially from some seasoned members. Am I on the right track?

Mod List:
-ETS FMIC
- ETS LICP
- ETS SHORT ROUTE UICP
- FIC 1100CC INJ
- WALBRO FUEL PUMP
-BATTERY RELOCATION TO THE REAR
-CURT BROWN PORTED I/M PORT MATCHED W/ THE S90 70MM TB
- EGR AND EVAP SOLENOIDS HAVE BEEN REMOVED.
- CURT BROWN PORTED CYLINDER HEAD
- KIGGLY SPRINGS AND RETAINERS
- GSC S2 CAMS
- SYNAPSE DV
- SPEED DENSITY INTAKE PIPE W/ K&N AIR FILTER
- MAP O2 DUMP ELIMINATOR
- MEGAN TEST PIPE
- TOMEI TI CATBACK
- ARP HEAD STUDS
- FP DBB RED TURBO
- FULL RACE TUBULAR MANIFOLD
- GM BCS
- OMNI 4BAR MAP SENSOR

Thanks!

What size of wally? What fuel? Fuel filter changed yet?

Pump: Walbro 255 - confirmed by shops that that is enough for my power output
Fuel: Husky 94 Octane in Canada
Fuel Filter: Are you referring to that little square filter on the bottom of the fuel pump? I changed that last Saturday, it comes with the install kit.

Your front 02 could be a contributor to your taking off lean condition but it would have nothing to do with your WOT lean condition. It only regulates fuel in closed loop operation (idling, cruising) while your fuel map controls the fueling in open loop (WOT).

What voltage is your alternator putting out?

Feel free to PM me the current tune, I usually only do SD tunes and will take a look. Is this on 2d or 3d?

data log? would like to see the ramp of how the car goes lean up top.

I gotta figure out how to upload my csv data log files
But I did a vd and here's a pic, I dunno how accurate the #s are but u get an idea until Im home

http://i734.photobucket.com/albums/w...ds/datalog.jpg

attached a zip
contains the logs

2x 3rd gear WOT pulls
1x 4th gear quick WOT pull

I tried loading the cruise ones but too big, restricted to like 100kb.

oh wow, please don't WOT your evo anymore until it is fixed man.

Do you have an exhaust leak before/near the o2 sensor?

I don't think so man unless its coming out of the sensor... I have the MAP o2 eliminator. its one piece to the test pipe.

haha don't worry i won't however I'm gonna do a quick pull when i swap out my sensors. I'll keep a close eye though don't worry :) I appreciate the look out though

UPDATE:

- Changed WB sensor, no change, while changing the WB sensor, we looked at my exhaust and no black stuff however I booked my car in the shop to get the test pipe gaskets changed b/c those were the only re-used ones and just wanna swap em for a peace of mind
- Changed stock FPR for another FPR, no change
- a lot of ppl said its probably not the front o2 sensor
- if its not those gaskets, last piece is injectors. However the injectors were bought brand new but anything is possible.

your car has got fueling issues bro...

next time you do a pull, and you see the afr's going past 12..... stop.....
dont keep going till it hits 13... like that plot shows. BADDDD.

wondering what fuel pressure you have at the rail during WOT.
this would tell you if you have fuel pump/filter/piping issues, or if you have injector issues.

i mean, are you positive that they injectors are scaled correctly?
if they are not.. this is the first step.

The narrowband voltage suggests that the AFR is correctly datalogging. The IDC is still only in the low 60% range so tacking more fuel in will combat the issue. Does this car have or had methanol on it? The other option is has been commented on that the stock filter assembly isnt flowing well as it has aged and dropping fuel pressure.

I would assume its scaled properly.

I don't believe it has had meth on it. According to your records as well, it didn't either. I remember you had a car similar to mine which had it but later confirmed this car did not.

Could you guys explain about the stock filter assembly. I keep thinking the fuel filter(which is some refer to as the sock) but I changed that already.