PLEASE HELP, strange problems(SR20det).

[owned by pandas]

Ok I have been experiencing a problem with my car for about a week now and I can't come up with a solution. Im usually pretty good at diagnosis but this one has me stumped. Before I start, let me just say that this literally came out of no where, and I didn't change anything in between the transition time of it running fine and it running bad.


The problem doesnt seem to matter weather the motor is cold or hot. If I start the car when it is cold/hot at idle it will go super lean(past 18 and wants to die), and I have to keep my foot on the gas a little and wait about a min and it will go to a normal idle afr. Now sometimes when I start it, it wont change no matter how long I sit and wait for it to go back, so I literally have to change the idle tune on the AFC, sometimes just to idle at 13 afr i have to move the fuel to +50 on the AFC. It seems to go back and forth with this problem and I cant seem to figure out why. Also other times when the car decides it wants to be friendly, when the idle goes back to its normal percentage on the AFC its at about +20 which is what I have always ran before. So basically I am having to change the idle tune from +50 or +20 back and forth on separate occasions just to idle correctly.

Second problem, after dealing with changing my idle tune almost every time I drive the car, sometimes while driving(which it runs good when it drives), there are spots where if I push on the gas just a little (cruise) the AFR goes to 10 flat. Then if I let off just a hair or apply just a hair of throttle it goes back to running normal.

I am confused with this. It has gotten me stranded twice so far(once it just would not start at all). I have checked and change a lot of parts and nothing seems to fix the problem, they only made it just a little better.

Things I have tested/changed:
-Fuel pump(changed when I got stranded)
-MAF(changed)
-Boost leaks(checked couplers and starter fluid spray)
-Wiring(grounds and power at ecu)
-Fuel pressure(Read 45 at idle)
-Cleaned plugs(just put them in a month ago), and regapped to a short gap.
-Checked all injectors and coils
-Replaced Ignition coil
-Checked PCV(ball moves freely)
-Changed Coolant temp sensor
-Swapped out BOV


My engine setup:
-SR20DET Redtop
-550CC injectors
-GT3071R turbo
-Nistune
-AFC neo
-JGY fuel rail
-Walbro 255 fuel pump
-Greddy front mount
-HKS SS BOV(on hot pipe, before the MAF)
-N62 MAF(I've always ran the maf blow through, about a foot and a half from the Throttle body on cold pipe.)

[jr_ss]

Why do you have an SAFC with a fully programmable ECU setup?

Have you recalibrated the wideband?

[owned by pandas]

Why do you have an SAFC with a fully programmable ECU setup?

Have you recalibrated the wideband?

I have a Neo in the car b/c it came with it and I ended up getting the nistune from a friend that had the same set up basically as me. So with the neo I had to adjust some tuning but it was very minor.

I have no recalibrated the wideband as it is self calibrating(AEM), I know the readings are correct b/c when it goes lean at idle it barely stays a live and dies. Also when it runs rich(10afr) on the slight throttle it runs so rich that is breaks up the motor.

[anti tyler]

Maybe he's just using it to have a cool light up digital read-out screen ?

[owned by pandas]

Maybe he's just using it to have a cool light up digital read-out screen ?

If you're not going to post something to either help or be positive please dont post at all.

[R3cK]

checked lambda sensor? (unplug / replace)
new petrol filter?

[axelfoxx]

i had a similar problem and i doubt it was 1 of the 2 but.. 1.. is your break booster or brake booster solenoid going out?.. you were saying idle was changing with gas instead of break so really doubt it was that.. but my car was having horrible idle problems with 2 hoses under the idle adjustment screw.. being pinched and causing eratic idle.. make sure theyre not getting sucked flat or pulled apart? maybe warped with heat? just something to try or look at, good luck