i asked this once before.

my understanding is that TPS-AE is a function of physical movement of the TPS vs a set time frame. that is pretty straight forward. i hope. i was successful overcoming the lean spike/bog by running OL and enriching the fuel tables(20%?) that i could see were used as i was depressing the pedal during normal driving. those cells seem to be seldom used in normal driving and if used they are moved through very quickly. i will assume in CL little learning is occurring there. to achieve a lot of AE early in TPS i added a lot more in 0-3-6% that i have see in other bins. that seemed to help. seems to need a big shot then taper off? maybe the opposite of what i have been used to seeing? have not yet done that.

now when is AE MAP invoked?

is it ever AE TPS or AE MAP -either or- and never both at same time? IOW does engine ever see at same time the effect of both in normal or brisk accelleration? i think it was said the AE MAP is invoked when driving up a grade. steady or slight throttle(little TPS movement) yet climbing up a 30 deg grade. maybe the ECU is monitoring a rapid change of manifold pressure and then allows AE MAP based on resulting new MAP cell?.

i have reached a point where i want to add a bit more AE but unsure if it should go TPS or MAP?

i have tried all diff combinations past year of TPS-MAP for AE. seems what i needed mostly is enrichment of all fuel tables and especially after tip in. thanks for your help in that.

 

can I bring this post back from the dead please

 

I keep pulling AE and my engine keeps running smoother. Opposite of what I thought, but hey, whatever. I guess with 90's and 14 psi with a super heated manifold (GMPP TBI VOrtec) you don't need that much.
I don't know enough about AE, so I just manipulate it with the RPM multpier table, and a little of the CTS table

 

this spring i started over by putting in minimal values in AE-TPS and AE-MAP and gradually working up rich until i was close to where i want to be. at that point i still had a lean bog at 2400-2800 that i addressed with the RPM multiplier. It fit well. I did take the advise of RednGold and looked at the VE learns at 2400-2600 and saw little learn above 50 MAP so added 5% in VE table there. will add more there after running current table.

A heated intake can be a benefit in a cooler climate. mine has no crossover as heads have no provision.

 

I wouldn't be surprised when to get some lean AE issues when winter comes back around, but whatever. What kind of car do you have (Ronny)

 

crossfire vette. 350 cid, xram, 2.0 TB's, 454 injectors, edel rpm aluminum 64 cc heads, crame 2040 cam 210/216 @.05, crane roller rockers, ceramic hedman 1 5/8 headers, dual exhaust/crossover, hooker aero chambers, 7747. Innovative WB.
CHANGES COMPLETED 10/13/2004:
7.4L TB on Holley TBI manifold(Projection), Summit AC with K & N, Aeromotive FP reg, Comp Cams 224/230 @.05 114 LSA, Innovative input of tps/rpm/map data.
09/2005 fresh paint(red of course)
08/16/2006 added Prominator- 8746 ECU with EBL, IAT sensor being added following week.

 

In the majority of ECMs TPS AE in whenever the throttle is opening. MAP AE is when the MAP increases. Some ECMs (port) have no MAP AE, and/or, they need to have TPS AE active to enable MAP AE.

There is some additional info for TBI, '8746 & '7747 ECMs here:

https://www.thirdgen.org/forums/diy-...s-aemap-q.html
https://www.thirdgen.org/forums/diy-...ps-vs-map.html

RBob.

 

Lately I've been graphing relationships and looking for useful patterns. Attached is an example of one such graph. The data set is of a 2nd gear full throttle pull.

The top graph shows an overlay of dtps, dmap, rpm & wb vs. time (approx 1 sec give or take). This graph shows where the map and tps ae are and what the effect is on the wb.

The second graph is just a better view of the wb all by its lonesome over the same time frame.

The third graph is of the entire data set for 2nd gear.

Just another perspective for analyzing ae...

 

I'm running the EBL - I pulled AE back 40% and am still going to 11:1 when I floor it. I will pull more tomorrow. My worry is that twice now when I go from 0-100% tps = stomp the gas... i get a backfire ( am pretty sure is through the intake) yet my WB reading still shows rich.

I've got 68lb/hr injectors on this engine. I think I'm going to go back and pull 20% more accross the board on both tps and map ae and see what happens. Right now I'd love to see a lean condition and know i just barely overshot and give some back but - I feel like I'm putting downhill as it is now

I guess I'll have to curve up the innitial numbers if i'm going lean for a split second in the intake but not long enough for it to register on the WB?

 

Did you have the backfire before you pulled out the AE?

Won't a messed up SA cause backfire through the intake?

 

yes. and I'm running the stock lg4 spark curve right now. I didnt want to mess with spark until i got the ve and ae in line then i can start playing with spark.

 

I've only seen lean cause a backfire (other then whacked spark timing, of course). Rich usually will just lay down for a while, then go.

It only takes 1 cycle of way too lean to cause a backfire. The burn is super slow, and still burns when the intake opens and then lights off what's inside the manifold. A wideband usually shows it as a lean spike if the filtering isn't too great.

You probably have a lean beginning (from the amazing throttle stomps), and then rich from AE and PE carrying on.

TPS Async AE is what'll be necessary to fight this. Async gets into the airstream right now, as opposed to next injection.

 

At low speeds the async does get it there sooner. Conversly with TBI, the async and sync pulses can overlap eachother, causing some of the intended injection to be lost. Ive been using sync for teh TPS AE and it seems to work ok. Without it, I get an enormous bang out the intake and then it goes when I mash the gas.

 

If it overlaps injections, just give it more AE in async. If it pops, it needs more. Not sure exactly how it worked, but I thought there was a "max AE PW" that could and should be increased, along with a software feature that accumulated the requests, and dealt it out as it was able to (which was supposed to not "lose" any of the fuel).

 

On TBI units async AE leads to an inconsistent volume of fuel. As Dimented mentioned many times the async AE pulse overlaps the sync fueling and the AE is lost. Other times there is no overlap and AE fuel is delivered. Or, it overlaps some and only part of the AE is delivered.

Even when there is no overlap the AE PWs can be small enough that delivery is inconsistent. Or, it needs to be accumulated for a time, then injected. Which causes 'chunkyness' in actual acceleration.

I switched to sync AE many moons ago, and it made a huge dfference. A smoother more consistent acceleration was the result.

Now on port injected engines, async TPS AE works out better. The normal fueling PW does not occur as often as a TBI setup. So the async AE is required for good throttle response. Then using MAP AE in the sync fueling to fill in.

RBob.

 

how do you switch to sync ae?

 

disable async totally-
Rbob gave me that advice. works good. combined with the proper offset (learned that one recently) sync is enough. I think I can get away with it running 2x90 inj @ 14psi
unless there is another way

 

ok cool... now can you explain offset? What were the advantages of async
?

 

to quote dom - "think of it as spark advance" for injectors.
61 pph at 13 psi- around 300 usec. my 90 pph inj's at 14 psi- 550usec.
re-do your VE tables after the change- you'l need to.
the table with the EBL is 'Injector correction offset'

with other ECM's it's probably something with battery voltage/pw or something

advantages of async? need the experts

 

what if i dont change the offset and just let VE tables relearn after turning off async? Is the offset change in Voltage or at a specific voltage that is the offset? EBL's glossary is vauge on that one. and the base bin I had already had offset at 396usec

Rbob... can you explain the premise behind the offset change ?

 

The offset is to make up for the opening time of the injector. As the fuel pressure is increased the injector takes longer to open. You can leave the VE table to make up for it, but it isn't the best way to go.

What to look for is the VE table taking a bathtub shape. If the lower MAP areas need a higher VE then the middle MAP area, then the injector offset compensation should be increased.

This is usually most apparent when running higher then stock fuel pressures.

RBob.

 

good info!

 

so I assume that to turn off async i would just set the tables so that there was no way it could activate? or is there a simple checkbox in EBL somewhere Rbob?

and is there a calculation I should use to determine offset? I have 68lb injectors with fp stock pressure. thought I'm not perfectly sure what that is yet..

 

set both asyn transitions to zero in the constants column to disable async fuel.
offset for 68's at stock psi- probably 50 usec higher than stock EBL. don't quote me on that...
I've found that offset is fun to mes with, especially when tuning idle. more offset=smoother idle for me anyway

 

why to disable asynch? for me it helped as I have 80 lbs injectors at 24.5 lbs(now 22) and when idle when asynch(open loop) the fuel was cut off and engine surged(stall saver?) . i believe it was attempting to maintain a A/F at idle it could not provide as too rich so it needed to flip to asynch. in synch the injector pulse dropped to 1.3 msec and idle was more stable.

 

I'm not really sure what you mean, Ronny. Async screwed me up, so I totally disabled it. I don't think I need it- my injectors are big like yours are. My idle is also 1.3 msec, sync only. The only time I've ever seen async come on for me is when I was on the dyno at about 2000 rpm, then I floored it to start the run. Async AE came on for a split sec. since the dyno run I turned it off

 

i believe i am 100% synch. i am uncertain if one could just disable asynch for idle quality only. i have not yet determined if my duty cycle is 100% as WB is dead. is being replaced as we speak. if i am at 100% duty cycle then i will up fuel pressure, keep synch, and run VAFPR i already have on car(aeromotive).

 

THat sounds good- you must have a hell of a car, man. I've probably asked, but do you run an open loop idle?
-what does your DC% read when your're on it hard? What about sync pw in msec?
MIke

 

pulse width idle is 1.3 msec and OL. i was over 100 on DC so went to 24 lbs FROM 17.5 FP i will say early last year. i dropped it back to 22 lbs this spring. WB is cooked so not sure if I am OK for sustained WOT. Issue is where to test WOT without causing other issues?

 

Would 0314 be the correct address for this (7747)? I see the values are usec. I assume this is a duration of time- added-the injector remains open? Numerically larger numbers should make for a richer condition?