VVT swap idle issues
 

I bought a 2001 VVT engine as a complete package with an MS3X, headers, exhaust, intake and all. While swapping the engine I also redid all the wiring and installed an AiM PDM. I checked all the wiring, and as far as I can tell, everything looks right: I tested for continuity multiple times, I get proper reading for the sensors on the MS3 and the PDM. The car is running, and I found a couple mistakes (at first it wouldn't idle because I forgot the diodes for the VVT and IAC), but now I'm completely stumped. After I added the diode the car will idle without holding the throttle, but the RPMs are climbing up to 3k and then they drop back down to ~1300 again on a cycle. It's also running very lean and the timing keeps climbing up to 30deg. I'm a complete MS newbie, my only experience is reading the basic stuff in the logs (TPS, AFR, MAP, etc) and I did watch all the videos in newbie friendly guide, but I'm trying to avoid messing with the tune and engine used to work fine. Can anyone help me check the logs and tune and see if anything jumps out? Thanks!

As the schmuck who sold @tadeuzagallo this setup, I'd appreciate anyone who could help him out. I've been trying to support his swap remotely but at this point I'm lost.

Your idle tune is a mess and uses pretty much none of MS3's advanced features and is causing a lot of your problems, but your 20kpa row is too lean and actually making it stall if I had to guess. I do not know exactly why, but it looks to give up and snap back to the cranking idle duty. I don't know what firmware you are on but it's not the latest, MS3 had some seriously inexcusable startup and idle issues for pretty much ever, you should probably upgrade to the RC firmware.

Thanks, that's all I needed to hear. I've watched the videos on the basics of how to get the idle tuned, but I had no reference to judge the current tune, so I wanted to get that checked before messing with it. I'll update the firmware and try following what was suggested in the newb friendly tutorial.

Select the bottom 3 cells in the 900 and 1100rpm column, press the equals sign, then type 60, tune from there. I prefer to have a column a couple hundred rpm under my desired idle RPM, yours starts at 900. That way if it does dip, at least it runs well. You have some aggressive idle advance correction, adds up to 14 degrees if it dips too low, that's probably why you're seeing 30 degrees timing. Also don't idle at 10 degrees advance, BPs are usually happier around the 15 range.

Thanks curly, I'll try that tomorrow morning and report back. I know I'll sound dumb, but I'll take that over messing something up, so just to be clear: bump the bottom cells in the Fuel VE Table, right? And then change it until it gets to ~14.7 AFR. I'll set the timing for the same cells to 15. Should I scale all the tables down to 700?

I did notice the aggressive timing correction, that makes sense.

Yeah. Start with 60 because richer is better than lean. Wait for WUE to be off (set a gauge to total correction and wait for it to read 100%), then go up and down to get a stable ~14.7 idle. Some setups can do this at 15.5, others refuse to go above 13.5. Later on you can target a 700rpm idle and tune that, and a 1200rpm idle and tune that. But by setting them all to 60, you avoid interpolation changes between cells, making it easier to tune IMO.

I followed that and it's *a lot* better now, thank you! I forgot to adjust the timing, and I still have to update the firmware. I'll also tweak the idle some more still, mostly for educational purposes, but I think it's pretty good for a track only car now. Should I be worried about the alternator voltage at 15.2V? I wired the reference voltage wire the lazy way, to the starter battery post, but if I understand correctly that could lead to lower voltage, not higher.

Oops, forgot to attach the tune and log