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Last seen: 3 years 11 months ago
Joined: 03/20/2015 - 17:24
AEM V2 lean tip in and stumbles on a 2jz

I have been slowly building an MKIII Supra for several years now. The current setup is a 2jz, single turbo, Siemens Deka 872cc injectors, on E85. I also went to an omni-power 4 bar map sensor this winter, while changing a few other things around. 

I'm not an expert with AEM, but I've learned a lot in the last 4 years or so. And by very gradually working on one piece at a time, have built a calibration that works, decently at least. Except no amount of research, searching, changing, and cursing has made this thing rev off idle well and still be properly lean at idle.

I've changed every setting related to accel size, and the only thing that ever seemed to help, was making the base map so rich, that it was basically the AEM stock 550cc map running my 82 lb/ers on e85. Very fat, like 'my 600 pound life' sort of fat. 9.5:1 AFR at idle. But it drives incredible. Revs like a formula 1 car, does everything I want. Just blows fuel out the exhaust and sucks an 1/8 of tank every 20 miles of cruising.

I had a friend who works for a shop that tunes GM cars take a look at it, so he's an HP tuners guy, not AEM. But I guess the basics are similar, and I don't have access to a lot of experts around here. His only suggestion was that maybe the injectors have some issue trying to ramp up quickly enough from 1.2 ms to whatever is needed for the accel pump event. Looking at my logs, I have wondered if it just needs more duration somehow. I've tried messing with the sustain, it never seems to make any difference. Any rate, enough rambling.

Attached: Two log files of blipping the throttle from an idle. Sorry they are just laptop logs, resolution isn't awesome. The lean idle calibration is probably the closest thing to a 'rev-able' version of my current driving around map. The mega rich calibration runs and drives, revs awesome, sucks fuel like a hemi cuda, and would probably require an oil change every 200 miles. I've tried just scaling the mega rich map back 20-30%, makes it suck like the lean map.





Thank you!

Last seen: 9 months 4 weeks ago
Joined: 06/06/2014 - 09:31
Took a quick look at your

Took a quick look at your logs and what I see are two extremes: one overly lean and one overly rich.  It seems like there'd be a "just right" somewhere between the two.  In your mega rich cal you have tons of base fuel with less aggressive accel fueling and in your lean cal you have less base fuel with tons of accel fueling.  It's like having plus ten and then minusing ten or having minus ten and then adding ten; the end result is the same.  Maybe these are just two examples that happen to be polar opposites but it's likely that your best combination of base fuel and accel fuel is between what you've posted.

Another thing that can affect accel fuel response is injector phasing/advance.  You've got an Injector Phase value of 17.625 and a fixed offset of 100° advance.  The coils and injectors don't actually work from the same sync point so with those values, I think you've got the injectors firing at a time that isn't very well matched with when the intake valves are open.  I've actualy specifically tested for good injector firing location (should be near TDC exhaust which is when the intake valve starts to open) and subtracting 1.5 from your ignition sync value will get the injector to fire in this approximate area (assuming 24 teeth per cycle and idential coil/injector phasing values).  Try setting your injector phase to 4 to see if it makes any difference.  I'd also zero out your injector advance table and only create an advance curve (if even needed) once you have a good base established.

Unfortunately there's no one-size-fits-all accel fuel solution and it does take time to get it dialed in.  I think you'll just need to spend more time testing different settings to see what nets you the best result.  If you haven't already, look through the 02v02 firmware upgrade notes PDF; there is a really good description of how all the accel fuel options and tables work and how they all work together.  One other thing to keep in mind is that without any accel fuel, you should still get at least a semi-reasonable throttle response.  If the motor reacts poorly on base fueling alone then you may need to do some more fuel tuning before getting into accel fueling.  

One last thing... your MAP signal looks really, really lazy.  MAP below 100kpa should very closely follow throttle.  It takes nearly a second to return to it's normal idle level once throttle returns to closed.  That's really strange IMO.

Last seen: 3 years 10 months ago
Joined: 06/24/2015 - 03:08
I had also massive problems

I had also massive problems with tip in with my v2 and 2jz. I haven't yet touched inj phasing from base cal, but one thing i found really helpful was setting "TPS filter" that is in base cal 0 and i found in my car good value is 6 teeth. After changing that throttle is alot smoother when starting to move and low speeds. Why i started to change that values because i tried alot in accel table with no results i wanted, then one day i had car idling and i watched accel tab channels and saw some movement in dtps value without even touching pedal (i have sensitivity 90% and trigger 0.8) and then i remembered seeing this tps filter and started to increase that and in about 5 teeth that dtps value came to zero and stayed there on idle, then i tested throttle and what a difference. Its not all perfect yet but alot better than it was, i think i still have to look into those injector phasing settings.


mk1 GS300 2JZGTE AEMv2

Last seen: 9 months 4 weeks ago
Joined: 06/06/2014 - 09:31
Are you running 01v24 or

Are you running 01v24 or 02v02 firmware?

Last seen: 2 years 1 week ago
Joined: 11/23/2014 - 20:59
i think ppl need to realize

i think ppl need to realize tuning an engine correctly is not an easy thing, go take some classes on engine tuning would help if you really want to do it yourself.

also please do not compare another ecu system which is a "stock flash" to a completely standalone system, the work involved in getting a standalone for an application might more than you can imagine.  

also if u got tune problem and you cant fix it, please go find a pro tuner and it will save u time and $. 

GK System - Efi and data acq specialist