Tuning transient throttle enrichment on aftermarket ECU

[pandaah]

i think a mod should change the title of this thread as this will do... riverz? lol

ive always wondered about wolfs, i dont know much about them but some people say there very powerful ecu's, other people say there shit but ive always wondered if thats cos they dont know how to use them properly

[JZA70 R]

lol welcome to 2008 guys...

http://www.toymods.org.au/forums/showthread.php?t=45377

[RyleyMA61]

hahah yeah i am suprised how many people haven't chimed in there!

re: misfire, sorry i meant that a misfire caused by a lean spike.

ie i was getting missing/stumbling due to leaning out when taking off from a standstill (throttle at constant position, bring clutch out to vary load)

making it run richer in these load points has solved the issue. got it driving very well now except the initial 16-18:1 AFR lean spike as you open the throttle (light) and about 14 (heavy)

the enrichment is done quicker, but the throttle scaling for defining map points is in "% throttle / 10mS" which makes it hard to get the really tiny inputs sorted without it enriching on just TPS noise. ie, these spikes occur at around 0.16%/10mS.... which is below the 0.5% deadband on the tps enrichment settings. lowering the deadband triggers enrichment events on the jittery signal though

so it's a compromise between annoying drivability and slightly lean mix for a split second on gearchanges at this stage.... apparently it can be fixed but at this stage it's still out of my league

[RyleyMA61]

and fuck me that launch control is good man! video rocks!

[thechuckster]

what is your timing doing as you open the throttle/take off? are you doing any accel enrichment based on MAP changes or just TPS position change rate?

and what size is the throttle and volume of plenum? If the throttle is too large, you end up with a stumble when taking off the line, e.g.:
- first movement of throttle changes MAP and combined with TPS change provides adequate accel enrichment
- a further movement of the throttle doesn't trigger enough change in MAP and the small TPS movement doesn't trigger enough fuel enrichment
- motor then stumbles
- greater TPS movement and change in MAP (as you give motor a bootful of the loud pedal) pushes you out of low load/low rpm region of your fuel/spark maps and combined with the TPS-driven enrichment you get more fuel and a subsequent increase in RPM

Low air speeds (as found at low rpms with big throttles) and minimal changes in MAP make for challenging acceleration tuning.


note: are you using TPS-only driven acceleration enrichment? that's not an ideal (at all) method for turbo engines. You need an approach that combines MAP and TPS changes for acceleration enrichment otherwise you will get lean events during boost.

[RyleyMA61]

Cheers mate it's all just standard 7MGTE throttle and plenum.

afaik the tps change enrichment is tps only, but the fuel maps themselves once the throttle is constant (or slow moving) is purely based of rate of change of tps signal, alas. tuning for big changes in tps signal is easy and pretty much done, it's the tiny tiny tps changes that are hard to get because i have trouble differentiating between tiny throttle inputs and throttle sensor noise.. well thats the drama im having anyway

[thechuckster]

TPS-only enrichment seems a bit underwhelming... Hitman's website suggests there are a number of features for tuning accel enrichment:
- Throttle Pump Enrichment
- Throttle Pump Sustain
- Throttle Pump Decay
- Throttle Pump Coolant Temp Correction

have you looked at the middle two on your ECU?

[JZA70 R]

Just some food for thought, I found it easier to tune, and gain positive results with almost all corrections turned off. This includes TPS correction and tip in, water temp (warm correction not cold start) and even air temp. By default every type of correction is on and usually with excessive values. I turned them all off and tuned from a blank map and had great results.

I guess what im trying to say is, sometimes automated sensor corrections can cause more problems than they solve. Sometimes is better to tune without aid, and only implement those correction when you can see a need for them.

[JustCallMeOrlando]

I'm with the above, get all the static stuff perfect before introducing corrections. In fact the Adaptronic manual from memory describes doing just that.

[RyleyMA61]

yeah chuckster im playing around with the combination of all those settings. perhapsi m jsut describing it badly.

yeah i did my base fuel map with no corrections- the car is driving well enough now that im turning everything off corrections wise and rechecking my fuel maps. corrections can be done later and is easier once timing/fuel is done

[RyleyMA61]

found out i had the manifold pressure line on the FPR hooked to atmospheric. idiot. -5.

with the FPR hooked up correctly, when the manifold pressure spikes, i'd assume a slight spike in fuel pressure, and therefore help transient throttle a little? even if it's just better than what i had

ideas?

[thechuckster]

lolz - rookie mistake

if you did your base tune with the FPR hooked up wrong, you'll need to re-do it ... then look at throttle enrichment.

fwiw: i think having an after market FPR with gauge attached lets you quickly identify pump and FPR-related problems.

[JP]

on my 2J, when the FPR base pressure is set to 46psi with the line off, it drops to 32psi at idle with the vac hooked up. blip the throttle and it jumps straight back up. I've got a Ti electronic fuel pressure sender wired into my ECU so the injector deadtime is a function of fuel pressure, also good for monitoring purposes.

[RyleyMA61]

yeah ive got a gauge to hook up this time and keep an eye on it. im actually using whole new fuel and timing maps this time, actually off a 7M and not a dumb-ed down 2JZ tune

thanks for the help!