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Title: Subaru Impreza- GH - 2008 US - AT fuelcut? Post by: ormopl on December 13, 2023, 04:21:12 AM Hi,
car i have here is: Subaru Impreza GH 2008 2.5i SOHC EJ253 AT Currently setup is: TD05 turbo on only spring acutator without any vaccuum fitted - boosting 0,5 atm 550 cc inj custom exhaust with afr sensor and egt sensor. Blow off. We are using RomRaider and ecuflash for programming, including tactrix interface. What i have done so far in the software i added the 550 cc injectors. Yesterday we did a chance to try to tune it. During partial load afr sensor is showing that ecu is following the openloop maps, even on the 70-80% load. Boost is stable, and even afr seems to be stable then, but of course needs fine tuning. The problem is when the throttle is WOT. It gets so lean that im not able to log it. AFR shows 14,4 and going up scale. Then it stops pulling, problably by the ignition. We tried to enrich it by CL, by the Tip in, and even emulating MAF sensor reading by external emulator. Always the same thing, AFR goes up so much we are not able to continue. The best AFR obtained was 14 using external emulation, but the correction was noticed - AFR was unstable, and ecu was still stopped pulling. Any thing suggested to be checked ? Any help would be appreciated. Title: Re: Subaru Impreza- GH - 2008 US - AT fuelcut? Post by: prj on December 13, 2023, 05:49:38 AM 1. Get away from the ECU.
2. Fit a fuel pressure gauge. 3. Verify that fuel pressure is dropping. 4. Fix the fuel pressure. 5. Get back to the ECU. Title: Re: Subaru Impreza- GH - 2008 US - AT fuelcut? Post by: ormopl on December 13, 2023, 05:57:59 AM prj,
thank you for the answer. Sorry, didnt mentioned about that. We have a gauge there. It shows 3,7 atm without dropping under load. As far as i checked, is a little more than designed 3.3 atm. Fuel system is stock, only injector were changed for bigger ones. Take care, Title: Re: Subaru Impreza- GH - 2008 US - AT fuelcut? Post by: prj on December 13, 2023, 06:14:26 AM Been a while, but I've mapped plenty of these with various turbos and never had any fueling issues.
Either the fuel pressure is dropping out on boost (do you have a fuel pressure gauge in the car?). Or you have a ton of misfires meaning one or more cylinders aren't running right. Anyway your issue is most likely not the ECU. A good idea is also to post on Romraider forum, we mostly do Bosch Motronic here. And don't forget to include the logs. Title: Re: Subaru Impreza- GH - 2008 US - AT fuelcut? Post by: ormopl on December 13, 2023, 06:30:45 AM Hi,
yes, we have a defi on board. Is there any possibility to have some data from TCU to manage the max throttle here? |