weird high AFRs out of a sudden - car run perfectly 2 hours before

[ChrisUR]

weird high AFRs out of a sudden - car run perfectly 2 hours before

    I currently experience very strange / weird problems with my '94 Single Turbo. Below you find a list of parts installed in the car for reference.

    We made some final adjustments to the AEM V2 map and the car run perfectly beautiful and was say 99% finished (you never finish a Supra). Because we have refilled the A/C system we wanted to turn the electric fans on with ignition. That was done by getting ign+ from one of the VSV connectors which are not used anymore due to single turbo conversion. Everything worked pretty nice, fans came on when turning key etc.

    Then I wanted to drive the car to my house and after a few minutes realized that it run like crap. Without pressing the pedal the AFRs were like 18.0 (which is the end of the Serial Gauge range). To make a long sad story short, the car is running WAY too lean currently and I have no idea whats the cause.

    Here is what we tested so far:
    - fuel pressure with ign on is 50psi
    - both fuel pumps are running
    - the AEM is running and has the same calibration as before when everything worked
    - all extra connections (I use an AEM extension harness) have been removed by connecting the AEM directly to the stock harness (only mod is the WB O2 tap in)
    - the electric fans have been removed (because we worked on them we thought however they have caused the issue)
    - all vac lines and couplers etc. have been checked
    - all sensors listed in the AEM have been checked

    the interesting fact is that when you make a temporary adjustment to the AEM fuel map and add 80% fuel (eighty) the AFR goes to 14-15 at idle.

    Is it possible that the AEM is damaged ? any other ideas what I could check ? every thought is highly appreciated as I have no clue what to do now

    Thank you !!

    Chris

    Parts overview:
    - Boostlogic T-76 Single Turbo Kit
    - RKS Fuel System (Dual Walbro)
    - HKS DLI
    - AEM V2 running latest firmware
    - fuel is race fuel (about 100 octane)
    - AEM Serial Gauge, UEGO, MAP 3.5, IAT, etc.
    - new ignition coils, new sparks (NGK 7)

[SV]

If you have an oscilloscope, you can scope the injectors to see if the pulse width they are at matches your fuel map.

[BBrooks98GSX]

What injectors? Some have reported the FIC 1680s change pretty drastically based on fuel temp.

[TitaniumThirteen]

What is your O2 FB value when this occur?

[Modular Wiring Solutions]

Turn off o2 feedback and knock control.

Then do this:

Add fuel to the map and try to get the afr at around 13:1 at idle. Turn off every injector 1 by 1 and see the afr changes of each one and find out if one is clogged.

What fuel are you running?