I wish we could set the notifications to notify on each reply instead of "one notification" for a new reply since the last time you checked in. If I check the site with my phone and it isn't logged in, then I don't receive anymore notifications on future responses.
Oh well, I haven't updated in a while because I have been chasing down gremlins. Nothing major, but nothing simple either.
Basically, every time I think I have my hesitation from idle to low pedal position fixed or at least almost gone, it doesn't pan out 100%. More like 98-99% but never 100% gone to my satisfaction. It is a silly thing to get stuck on but I am a perfectionist and I don't want to settle for the little bog that I have been getting (900 rpm), then perfect everywhere else. So, for the last couple of weeks I have been dissecting logs and tunes trying to work it out.
Apparently, the ecu wants to see perfect harmony between the MAF and MAP sensors on low throttle inputs and they can diverge more as rpms increase. It is a weird combination in that the MAF controls fuel based on airflow and the MAP provides load data used in the overall load calculation as well as the look up for the spark table.
These seem to be somewhat independent in that I can adjust the MAP signal and get a more aggressive spark curve while not affecting fuel trims significantly then all of a sudden they are completely co-dependant at idle and off throttle.
I've played around with maps based on a percentage of change, commanded voltage, using the load of the sister sensor, etc. However, I think I have settled on the most involved and hardest to tune strategy; MAF -> MAP conversion. So this weekend I put hours and hours and hours into building a new MAP table to perform a MAF delete (while leaving the MAF in place for reference voltages). The added complication here is that with the SC in place it throws off the airflow under all circumstances and the ECU doesn't like some of the real values. Therefore, I have to fudge reality with what is supposed to be seen on a stock motor and make the MAF work with the MAP and Fuel tables.
This is the only way for me to command under all circumstances exactly what the MAF is relaying to the ECU as well as the MAP sensor. The early results so far are a good idle, conquered the hesitation problem, but now when I let off the gas it hunts all over the place and wants to die
So I shifted my problem from one area to another and it is just so darn hot outside that sitting out in it is bad for me and the car. I'm going to have to change the oil just from all of the idling I've done in the driveway tweaking the air and fuel curves
So, I've been trying to hit it early in the morning and late at night which further limits my actual time in the driver's seat.
Oh well. The good news still, is that she runs great everywhere else and I don't foresee any issues power tuning. Everything seems to behave once I get her past 1,000 rpm. It is just the low end stuff right now that is a bit bonkers. Part of the problem is that the Rotrex flows more air than necessary. A little bit of pressure builds up pre TB and when you first touch the throttle, there is a voltage spike on the map sensor, the aem map sensor, and the maf. The stock ecu doesn't like to see a). a voltage beyond x and b). too large of a differential between maf and map in this area of the map, so it cuts fuel to pull it back down. This causes all kinds of funk in all the wrong places
I'm kind of past that and now have the other side of the sword to play with. The bouncing around after low throttle input is caused primarily by my MAP conversion tune, the fuel not agreeing 100% with the voltage I've supplied, and O2 correction. I have to get each cell in 100% agreement and there is going to be quite a bit of trial and error with this issue. The curves in this area are notoriously delicate and .1v here or there throws fuel off and if it is more than x% the engine stumbles.
Oh well, at least I am headed in the right direction and the actual hold up is quite small in the scheme of things.