zen Posted February 27, 2022 Share Posted February 27, 2022 Hi guys, After a head refresh I've put in some BC 264 cams. Car is stock ecu and stock fuel for now. OEM narrowband is in place. It's a jspec, so it's MAP. Like expected the first start was a bit rough and stalled a few times. After a while the car started running a lot better, however my idle is around 11-13 AFR. Even at 5-10mins at idle. Is the stock ecu able to relearn the fuel trim to the proper AFR with aftermarket cams? Maybe I should drive a few miles to see how it is adjusting? What AFR's are you seeing with aftermarket cams and stock ecu? Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted February 27, 2022 Share Posted February 27, 2022 No, the ECU cant relearn. Bigger cams dont draw as much vacuum as stock cams, less air flow means more fuel, Ive been through it myself. Adjustable cam gears help to a degree but you'll need to time them up with the cam card if you havent done already You'll need an after market device to trim the fuel back Quote Link to comment Share on other sites More sharing options...
zen Posted February 28, 2022 Author Share Posted February 28, 2022 Thank you. What would be the best short term solution to this? Put in an afpr to lower the fuel pressure? I would like to upgrade the fuel system and ecu to standalone later this year. I just need to get it through emissions for now. Thanks again. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted February 28, 2022 Share Posted February 28, 2022 Short term - Put stock cams back in and wait until you have all the bits together, theres no easy fix. Lowering the fuel pressure wouldnt be advisable 2 Quote Link to comment Share on other sites More sharing options...
thevork Posted March 1, 2022 Share Posted March 1, 2022 It's best that you lean the closed loop out somewhat with an AFPR. You won't need much and it will help AFR's on higher boost too Quote Link to comment Share on other sites More sharing options...
zen Posted May 18, 2022 Author Share Posted May 18, 2022 A little update. After speaking to several tuners with plenty of Supra experience , I decided to follow my initial AFPR route. I have adjusted the AFPR to Toyota OEM spec. The AFR is good at idle, cruising and WOT. No issues at all. Lambda is also where it should be. Fresh MOT as well Quote Link to comment Share on other sites More sharing options...
Noz Posted May 18, 2022 Share Posted May 18, 2022 Glad you got it sorted. What's the benefits from 264s on stock ecu? Quote Link to comment Share on other sites More sharing options...
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