in ae delta throttle contrib vs delta tps it works by saying
if i change my tps position by X percent i will add so many
microseconds to the length of time my injectors are open ?

in ae delta map contrib vs delta map it works by saying
if i raise the numerical value of the map by X amount i will
add so many microseconds to the amount of time the injectors are called to be open

how long do these values stay in effect ? if i move the throttle
10% ae makes a change and then stops making a change
after some length of time or is there another condition that makes ae stop its function ?

mike

 

1) X Percent per period of time, a slow moving TPS won't trigger AE.
2) Yes
3) There is usually a decay rate, and coolant temp correction.

 

thanxs

 

Just looking for additional clarification... If slow moving tps won't trigger AE, what is the 0% delta tps cell for in the AE vs diff TPS table ($61 mask)?

 

So that there is a beginning.

You have to have a beginning for the range of 0-3%.

All the TBI code that people are *used to* will be obsolete when the Ultimate TBI stuff is released anyway.

 

Teh 0% cell is so teh AE can decay down smoothly after TPS AE has been engaged. Basically after you open the throttle the TPS term for the AE slides back down the TPS AE table untill it reaches zero.

 

If i'm reading this correctly, when I move the throttle 4% in 12msec ($61) the AE usec in the 3% cell will be added to the PW and then be reduced down to the 0% cell at some predetermined time interval.

Would the same thing happen if I move the tps .5% in 12msec or is there a minimum amount of tps required before entering AE? If no minimum tps movement value exists it would stand to reason that just about any time i move the throttle would envoke some sort of AE response.

I'm very lean on light throttle movement, which is extremely fustrating.

Yes, I will probably look into the U-TBI setup once it comes out. Just having access to the programmer will make tuning infinitely easier.

 

You probably need more MAP AE. With the tps AE, theres a min ammount of delta TPS needed to engage the AE. After that, if your using the truck AE with the filtered TPS term there will be AE untill the slow filtered TPS catches up with the actual TPS, or you back off the throttle. If your using the standard car TPS AE ($61), then the TPS is based on the rate that the throttle is opening. Faster throttle opening = higher table values. IIRC, theres a min value to engage it as well but there will be AE untill the throttle stops opening or begins to close.

 

BTW, the fast TPS AE is really only for teh initial shot of AE needed when the manifold starts filling. for sustained lean condtions after you tip in, look at the MAP AE.

 

Thanks for the info ... not enough AE is probably the reason my blm's are droppin' off. I'm tryin' to compensate for lack of fuel by boosting the VE...

Need to add a smily with the light bulb going on........

 

I increased my map AE and improved my lean spot on light accel. my current AE is as follows;
Delta map, usec
0, 600
20, 977
40, 1624
60, 2051
80, 4102

I plan to increase these values even more. I'm just wondering if this seems like alot of AE. I'm about 3x stock values. I realize that an open element filter and manual transmission tend to require lots of AE.

I'm currently running 90pph injectors at 10-11psi

 

i decided to run OL a month ago. i believe i am using main fuel tables to add some enrichment AE for normal around town accelleration. those rpm/map cells that are populated during 1/2/3/4 gear shifts in town after tip in are enriched in my tune and need to be more so in fuel tables. i can see ther A/F enrichment from AE/TPS then it dissapates quickly. i hope to add AE by fuel tables and verify. maybe i am wrong but i thought i heard AE/MAP is used for changes in map when little tps movement occurs(up steep hill). i am wondering if i need much AE MAP if i can do so in fuel tables ?

also those low rpm high map cells during acceleration seldom see BLM corrections as little time in them. right?

with OL operation my A/F stays where i want it and BLM does not remove fuel i desire. any truth in any of this?

 

by using the VE as a pseudo AE aren't you enriching your overall tune? For example, when the tps or your map moves you need a certain amount of AE, but when you hold your throttle steady and the need for AE passes you are still adding that extra fuel enriching your mixture.

In regards to the BLM adjustment in upper map low rpm, it appears to me that it takes in the neighborhood of 20-30 sec in a particular area before it settles out (depending how far off your tune is).

I think I'm having pretty much the same problem you are. When it's in OL warm up the car runs great. When it's in CL my blms tank and annoying lean spots develop on light throttle movement.

My O2 never stabilizes, it swings anyware from .75v down to .018v. I'm thinking about starting a thread about tuning the CL PID. I have read the ECM Proportional Control paper and apparently I'm not getting it.

 

The Closed Loop control is SUPPOSED to NOT stabilize the O2 voltage. It sees lean, then adds fuel until it sees rich, then removes fuel until it sees lean, and repeats and repeats and repeats and repeats. Integrator is doing this. BLM watches integrator and tinkles it's way in the direction of the Integrator.

The O2 sensor, once warm, practically CANNOT stay between 350-550 mv for ANY length of time, even open loop and perfect control.

BLMs are slow moving, that's for sure, but for good reason in most cases.

Sounds like your VE isn't done right, if it's going to pot when in closed loop. What's your procedure for adjusting your VE? It should be done in closed loop, warm engine, EVAP/Canister purge disconnected, EGR disabled (in the software), some people like PCV vented to atmosphere, some don't. Use closed loop and BLM to adjust VE. Adjust until BLMs stay in the 120-128 range.

 

What happens when the EVAP/Canister Purges?

 

It lets in fuel vapors from the fuel tank. That'll just ADD fuel on a MAP system. IF the EVAP has no fuel, the air that it allows to the engine registers only as MAP, thus no compensation needed. IF it has fuel (and usually does), the fuel gets removed by closed loop. True VE would not include that fuel. If you want, though, you can calibrate with it on, and shoot for a lower BLM (<128).
Just realize that filling the tank, or calibrating on a hot day, or idling for a long time will affect the calibration due to EVAP and other things.
When the tank gets hot, lots more fuel comes through purge, and with these return style fuel systems, the tank gets hot when the engine is running.
Others may say to tune open loop with a wideband, which works fine, but isn't necessary, and there are SOOOOO many things that can cuase fuel changes in fuel requirements that I MUST recommend closed loop for the average guy.
Good Luck

 

I miss spoke when I said 'stabilize'. I realize that the O2 continually switches back and forth between lean and rich. I am, however, under the impression that your lean / rich thresholds tell the ecm what is lean and what is rich. So if the O2 swings beyond these thresholds it will begin the fuel correction process. Are swings down to .018v normal? It seems excessive to me. But then again I don't know...

Also the lower I set my VE's the worse my lean spots get. I have the egr disabled in the code, the EVAP/canister purge is not.

This is good input, I appreciate your comments.

 

How do you disable the EVAP/Canister purge?

 

Are your BLMs going down or up? If the steady cruising results in repeated switches down to that voltage, and up to about .7v or higher, then it's fine, IMO. If it's just during tip-in, then you may need some VE and or AE calibration work.

EVAP disable = remove the hose from the canister to the engine and plug, then you're gauranteed no EVAP, and don't have to fuss with the software.

 

blms are dropping, mostly on very light throttle or at the coasting threshold. I have the DE, DFCO and Async disabled in an attempt to isolate the problem. So far no luck I have been messing with my AE as you can see from my previous posts with limited results.

 

What size injectors and fuel pressure are you running?

RBob.

 

Quote: by using the VE as a pseudo AE aren't you enriching your overall tune?

overall no. i did a lot of datalogging in CL. winALDL. i find i get few hits in those cells that are populated briefly when i accellerate normally(??) fron a standing stop or a cruise through subdivision(very hilly) from stop sign to stop sign. i sort of labeled them and in tune added about 15%(?) more value. these are 800 rpms 1000 rpms up to 2200 rpms all at the higher map areas that the normal accelleration puts me in. now in CL there was some correction going on but little. i wanted zero correction so i keep those values on rich side. in my WB log i see AE (13/1)but then it times out(i know it is filtered) and i get a lean spike. so i feel fuel tables can add AE. especially in OL.

my CL operation shows BLM 122(today) accross the board. on OL that results in 13.5/1 at idle and 16/1 at cruise speeds over 60 MPH. in city 14-16/1

my OL is an experiement. car seems to run better. i have a somewhat large cam (224/230@.05)and stock gears(3.05). settled down especially at idle. IAC is not as erratic. before it was chasing its tail. another issue with CL is that i believe i was going asynch too often(per winALDL) at idle and on-off-on with injectors. so A/F was up-down on WB.

another reason to run richer than 14.7 is i am non emmishion compliant. no cat-con to worry about. i heard 14.7 was to keep cat-con happy and prevent damage to it. no testin here in Hurley WIS.

also i have somewhat larger intake area as well as runners in head. it can suck up a lot of fuel in low rpm use. condensation? my normal driving is low rpm and i tthink it falls out and condenses. helps to be a bit rich? this is a TBI after all with 80 lb inj's at 17.7 lbs. so need to compromise to rich side. when on the cam 2500 rpms up less of an issue as venturi velocity is better and the runners are sucked clean(i like that expression!) of any wetting.

feel free to comment. a lot of this is uncertain opinion.

 

90pph @ 10-11psi
injector bias set to 549 usec

Still lean at throttle tip in and decel. When DE, DFCO and Async is disabled does something else intentionally cause the motor to go lean?

 

The reason I asked about injector delivery is that your statement "My O2 . . . it swings anyware from .75v down to .018v."

This is controlled by the proportional gains. When going to a larger injector the same proportional gain values will provide a greater swing in fuel delivery. Usually too much.

Any chance when the car is warmed up and during light throttle cruise at say 45 - 55 MPH, is there a sound or feel in the engine like there is a steady WOooWOooWOooWOooWOoo?

One way to calibrate the proportional gains is to reduce them until the INTegrator starts forcing crosscounts. It will do this by increasing then decreasing is a steady fashion.

Then add proportional gain until the INT holds steady. This type of calibrating needs to be done during steady state cruising at various engine speeds.

With the larger injectors the AE should be too much. And need to be reduced. It may be worth while to double check the fuel delivery system. All too easy to have a 'just not enough fuel.' AE places a large, immediate, and short duration demand on fuel delivery.

It's that short duration that makes it so hard to pick up on a mechanical FP gauge.

RBob.

{edit: here is a thread with a couple of data logged graphs showing how quick a fuel pressure drop out can be during AE(about 1/4 second):

https://www.thirdgen.org/techbb2/sho...hreadid=134833
}

 

Yes, I expirience the "WOooWOooWOooWOooWOoo" on light cruise and decel at various speeds and rpms.

I have my O2 proportional gain set to roughly 1/2 of stock values. I never went any further 'cause didn't really know what I was looking for. Also my Winaldl is pretty slow I didn't want to do any damage because I have to guess what's going on...

Excuse my ignorance, but could you define cross counts?

As for my fuel system. I'm running a 255lph pump (new this year)with stock fuel filter, -6an supply line and stock regulator. If the mechanical fuel gage is too slow to see a potential drop in pressure would a standard run of the mill electric fuel pressure gage work better?

 

A cross count is when the O2 value moves from rich to lean, or from lean to rich, across a set boundry.

As for an electronic FP gauge, don't know. I've never tried one. All depends upon the dampening. Observing the gauge at a stand still while wacking the throttle will help. In gear gets to moving things around too much (physically).

Using an '8746 or '7747? Try further reduction in the prop gains at low airflows. See if that helps light cruise and decel.

RBob.

 

It's an '8746. I'll mess around with prop control some more.

Thanks for the help...

 

I might have missed something here, but how is it lean if the BLM's are dropping?

 

That is exactly what's fustrating me soooooo much.

My gut and O2 say lean, my BLMs say rich

I'm gonna mess around with my prop gains and see if it helps. I figure once I get my O2 to stabilize I'll probably find that my VEs are pretty rich. Close to 100% VE with 90pph injectors is a lot of fuel

 

You mean the BLMs will go below 128 (rich) and the O2 voltage is not above .500 like it should be for a rich condition?

 

Yes, It seems to go to the extremes. BLMs will go to 108 (my min BLM setpoint) and the O2 will swing anywhere from .75mv to .018mv. Low map low rpm is where it reads lean the most.

 

someone jump in here. is it possible it is going ASYNCH and inj's turn on-off-on-off with INT-BLM responding to uneven fueling? mine go asynch just like i stated(80 lbs with larger cam at 800 rpms). so i am running OL today. 40 deg this AM maybe i need to make a correction

 

How long does this last? Youll only see lean from lack of AE for a few seconds.

 

DIM: i am used to seeing lean on WB when i deaccellerate from 70 mph without breaking. i have DFCO disabled(i think so) as well as highway enleanment(whatever it is called). when TPS goes to 0% i see A/F go to about 20-30/1 and then recover when i come to stop sign. no stall it just comes back to14/1 or so at idle clutch engaged. i thought this was a mechanical thing where the fueling is greatly reduced with large manifold vacuum it shears off the fuel on intake surfaces. kinda sucks the manifold dry(i like that analogy!). is it possibble my 20 map fuel cells are lacking in value? i thought they were 122 last i checked. OL.

 

Its possible, but the injector PW is also getting really short, so you may not be getting the fuel thats commanded by the computer.

 

I read somewhere that the injector bias should be increase with larger injectors to keep them from "shutting off" during short pw.

Is there any truth to this? I raised mine from stock 396usec to 549usec (90pph injectors @ 10psi). I didn't notice much difference on decel and low map fueling. The only thing i did notice is that my idle is fatter.

quote:
--------------------------------------------------------------------------------
Originally posted by dimented24x7
How long does this last? Youll only see lean from lack of AE for a few seconds.
--------------------------------------------------------------------------------

lean spots mostly last only a few seconds. Alot of the time the lean spots appear on the transition from light decel to light cruise. I've increased the values in the lower cells of the delta map vs AE and it seemed to improve things.

My o2 does seem to wander though. From what I have read, it seems that most people's O2 swings from somewhere around 14afr to 15afr predictably (is this true?). Mine will wander all over at steady throttle (or what appears to be seady throttle)

I'm sure I have more than one problem affecting my lean spots.

Weather's been crap lately I haven't had any seat time this week to play around.

 

Quote: The only thing i did notice is that my idle is fatter.

if you are in CL how can you control the A/F? are you OL only at idle?

maybe someone can explain how increasing the time on can help the fact they are shutting off. it would seem they are on longer and then off longer by increasing that bias.

i too see lean spots on WB even in OL. not sure if that is a problem. as if i was to enrichen it may affect fuel mileage. as i posted before i would like to see a carb logged on my WB with my current set up. would it be enriched with bad fuel mileage and better drivability. carb is MAF and i am SD.

 

Theres also pump shot for coming out of decel fuel cutoff and decel enlean. Might want to check those out as well if your lean after decel.

 

DE and DFCO are disabled. I've started disabling anything that remotely affects fuel delivery to try and isolate my troubles...

 

Oh yeah, async threshold values are set to 0 as well.

 

Question on DE; I have and DE enleanment factor. If I increase the value will I increase or decrease and afr?

 

I notice it during OL warm up and in CL my BLMs dip even further.

 

A larger DE Enleanment Factor ($26F in the '8746) will decrease the delivered fuel. There is also a DE factor vs coolant table at $32C ('8746). A larger value will decrease the amount of delivered fuel.

The final DE factor acts directly on the PW. It reduces it to decrease the amount of fuel being delivered into the manifold.

The purpose of DE is to compensate for the fuel film held on the manifold and runner walls. As the throttle closes the manifold pressure drops pulling the fuel film into the air stream. This can/will cause a rich AFR.

If DE is disabled or is not sufficient the INT will drop in response to this excess fuel (not to mention the wasted fuel and high emissions). As the INT drops and the fuel film stabilizes the AFR will then go lean. At that point a stutter or hesitation can occur.

RBob.