| I just finished a bunch of work on my 93 TT. 300 degree fuel rail, Nismo 740cc injectors, Selin dual MAFS intake, SZ ECU. I also fixed a few boost leaks. I haven't boosted yet because I am waiting on my wideband to arrive, since I know I have been running lean. So it's possible that once I try to boost, I learn more about the state of the car, but right now it seems to be running and driving totally fine, except for one issue during the first few minutes of cold start. I discovered this issue while every so lightly touching the throttle cable while the car was still warming up. Usually I never touch the throttle at all until the car is warm, so it's possible that this problem isn't new, and that I just never would have encountered it before. I also don't know if it's something I would notice if I was using the accelerator pedal to move the throttle (more coarse movement) as opposed to lightly touching the throttle cable with my hand. I found this forum post which seems to describe my symptoms exactly, but I don't see any resolution in the follow ups. I collected conzult data during a cold start this mornining. I'm no conzult expert so there might be something in the data that I am missing, but after my first review of the data, it seems to me that my problem is timing related as described in the post above. Until the coolant is at about 130* F, when the throttle is touched just enough to turn the throttle closed switch off, the timing drops immediately from upwards of 35* to 15*. When this happens the motor bogs for a second, but then recovers. I believe as it recovers the timing advances again, but unfortunately I didn't collect enough data this morning to confirm this 100% (I didn't wait long enough after the bog to see what conzult would capture as the motor recovered). Once the coolant temp is over 130* F, and the idle timing is down near 15*, a light touch of the throttle causes the timing to advance to upwards of 35*, and there seems to be no problem at all with the idle/motor (no bogging/hesitation). Just because these things are often questioned in relation to idle/hesitation issues: The TPS connection is clean and tests within range. I don't think I have any problems with my air regulator, IACV/AAC, or FICD. The car idles fine and all the data I have collected from these sensors looks normal to me. Once the car cools back down I'm going to collect data again and wait longer after the car recovers from the bog, so I can confirm for certain that the timing does advance again as the car recovers and I'm still lightly on the throttle. Does this ring any bells for anyone? Thanks.
Andy
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