Jefferson.C Posted August 20, 2021 Report Share Posted August 20, 2021 Been trying to figure out why I am having this lean spot at roughly 2500-3k mark. I don't recall this being a problem when I had stock cams fitted, I have recently installed some Tomei 256 pon-cams. It's RB25 with RB26 ITB's. NZ trigger kit. Quite heavy valve springs so I do get a little VCT gear chatter but otherwise healthy strong engine. The A2 GP output is my VCT switch to clarify on the log, though it's ON and does not appear to be the issue. The only way I have been able to mask the problem is by having larger then normal VE values in those areas. The only thing I can see is my short pulse width adder table at around that 3ms mark goes from 0.000 (2.875) to -0.0048 (3.000) then jumps to +0.0032 (3.125) This is the information I was supplied from ID so I will assume it is correct? I am not sure if this is what would cause such a problem or it's just the nature of these camshafts and air movement through the engine at that particular RPM and load. Keep in mind my o2 sensor is located at the bottom of the downpipe, so expect slight delays Aug20.llg 240sxAug20.pclr Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 20, 2021 Report Share Posted August 20, 2021 Possibly some fuel pressure resonance. I wouldnt stress about it too much, you are only 4-5% off target. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.