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how do i know when i need more TPS AE or MAP AE? or when to move one over the other? is my assumption that tps-ae comes on first and map-ae comes in slighly afterward? does the map sensor lag a little behind the tps? it seems they are similar just using diff sensors. i further assume they are added togther rather than offset. IOW 2 + 1 = 3. not either or on net result. what if i zeroed out my map-ae table and just used the tps-ae? what is effect? not all aftermarket efi use a map sensor? reason i am asking is that i tried and tried to get my AE in line. i upped AE 5% per burn tps-map equally from what i believed was a stock bin. finally saw results at 200%-250%. i still need more. but i am closing in. i see the stumble at a wack of throttle wide open when engine under load. somewhat ok when rpms up to 3000 and do same. i plan on adding only TPS AE only at upper % in my TC program and give it a try. now TC added for me the lag filter. i asked the Q once before but i assume that takes the same quantity of AE and spreads it out over a longer time span. is this partly accurate? i see values in lag in TC of like .18. what does that signify? would raising that # spread out effect over more time? or does it lenghten the time effectively providing more gross fuel over more time? like same pressure but longer "on" time. hard to explain. sorry for all the Q's. have not tuned this summer awaiting the phase 2 mods this july. all prior tuning done last year.
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Originally posted by Ronny how do i know when i need more TPS AE or MAP AE? or when to move one over the other?
That's one of the areas, that's as much art form as any thing else.
**Generally**, you want enough TPS AE on light to moderate brisk acclerations. Then just enough MAP to fill in the top.
Then, enough MAP AE for slight acclerations going up hill.
After doing a 1,000 chips, I still spend alot of time getting it right. And I'm serious about that chip count.
i believe i was misinterpreting the AE/TPS. i see after LOOKING at it this evening i see it only goes 3 to 25% TPS. i assume that means a small movement of TPS at any specific position. a 30% movement just uses the values in 25% constant as table only goes to 24%? ? so my statement above on zeroing out the MAP is way off as i would not see the massive amount of AE that i believe i needed as compared to stock(?) tune. so it appears the AETPS is the lessser amounts of pumpshot as you suggested and the AE/MAP is where i need to go as far as more PS to reduce stumble. i am further assuming i can move air easily(r foot) vs atomized fuel mix. i tried a hammer of throttle this AM in second gear at about 20 mph/ about 2400 rpms and the cough was real bad. i think i was barking up wrong tree(BUWT) by looking at the AE/TPS primarily as that is where i added the most PS. I think i will reduce that back to about 150% of stock and go back to MAP and verify that is 250% of stock and add on another 20% and try again. also read a post by demented that was helpful. will reduce the PE invoke to 60%. or should i leave at 70% untill see results with AEMAP so as not to confuse results? spark tables stock to best of my knowledge.
Originally posted by Ronny i believe i was misinterpreting the AE/TPS. i see after LOOKING at it this evening i see it only goes 3 to 25% TPS.
yep
And AE exists to just get you into PE. If you have to run *too* much AE the you'll have to lower the PE TPS enable.
Not to mention with too small of injector, you have to run lots of AE.
I'm very sympathetic. On the larger TB engines that I've tuned, they've required tons of acceleration enrichment. Another thing that'll make you chase your tail for ages is the Block Learn. If you are going from a 108 BLF and then smacking the throttle open to an area that needs 128, it'll pop, even with good accel. Block learn updates much too slowly for that.
AE TPS is sampling TPS % change OVER 12.5ms, which is why the %TPS is so low, it's not based on the starting or ending TPS. But other than that, I think you explained it pretty well, in that the TPS is for the first instant, and MAP is the filler after it. If the car falls down and stays down, it's not AE's fault though.
Accel enrichment is BEST calibrated with a wideband though.
ugh, I have to get back to work. Trying to get our Saturn to drive well.
Joy!
__________________ -Jeremy- EFI Calibration Engineer, Director of R&D, Software Designer (Fuel Injection Technologies - dianpen.com) - still in China since Nov '04!!!
86 Z28 - rusty, tired, and in storage - 89 GTA with plans, but - also in storage now needs paint - badly, 79 Malibu classic with 91 L98, 4L60, 3.73
I need to do a writeup on '7747 AE. . . There is a lot of adjustability in the '747 AE routines. Both the TPS and the MAP terms are lag filtered to provide the delta terms. The lag filter variables are based upon the coolant temperature (two 2d tables).
The delta TPS & MAP terms are then used to lookup the amount of AE to provide. This provides a PW based value. These two values and the IAC opening value are added together and then compensated for coolant temperature.
The result is the amount of async PW for AE.
The biggest problem is that the delta TPS AE PW table only goes to 25% delta TPS. For an engine being fed by 2" bore TBI(s) this table really needs to be doubled in size (to 50% delta TPS).
Else, at a true 25% delta TPS the AE is good, then at a true 50% delta TPS the AE is not enough. Then it can go the other way, rich AE at 25% delta and OK at 50% delta.
The delta MAP AE can be troublesome as on a stick car it is easy to produce a large sudden increase in MAP. Done at low speeds and the engine can be flooded out.
But MAP AE has benefit. First it is important to understand why AE is required. On a wet flow system (TBI) there is a portion of fuel wetting the walls of the manifold. There is also fuel in suspension within the airflow.
A major reason for AE is that when the throttle is opened the manifold pressure increases. This causes fuel to drop out of suspension and add to the fuel on the manifold walls and floor. Without AE the mixture reaching the cylinders would be lean.
The higher the airflow velocity, the less fuel will be on the walls. And, the less fuel will drop out of suspension with an opening throttle.
The TPS AE does not take into account the amount of manifold pressure increase. The MAP AE does. As long as it isn't too much at low engine speeds.
I've found that it is a real balancing act to get the AE all worked out. I ended up doubling the size of the delta TPS% PW AE table (to 50% delta TPS), and adding an AE vs RPM compensation table. From about 1800 RPM down I taper off the total amount of AE.
I then datalogged the WB, the delta TPS, the delta MAP terms, and the AE PWs from the TPS & MAP. With that information I was able to tune in the proper areas of the tables. I also cheated a little on teh VE table. Below 1400 RPM I increased the VE% above 75 KPa. This filled in for the AE that I tapered off in the RPM compensation table.
At this point I can run the engine up to 1800 RPM in first gear and just as fast as I can plant the go pedal to the carpet. No more bog, it just goes.
So, I can hear someone ask, what happens if the engine is at 3,500 RPM and the go pedal is planted? On the surface it would seem like there would be too much AE. The airflow is high, so not much AE is required, even if the MAP increases somewhat.
This gets interesting, as very little of the actual programmed AE is injected. This is because most of the available PW time is already taken up by the normal injection of fuel. And since the AE fuel is async it may or may not overlap the sync fuel pulses.
The delta MAP AE can be troublesome as on a stick car it is easy to produce a large sudden increase in MAP. Done at low speeds and the engine can be flooded out.
so it appears my assumption of not enough AE may be incorrect!
at moderate rpms(2000-2500) and low speeds 25 mph or even at cruise speeds(60mph) possibly what i am experiencing is too much AE coming from high MAP's and subsequent massive PS with my stick car when i floor it. looks like i was going in wrong direction.! as i stated in post i was of opinion i was lacking in AE day one of mods and continuously upped AE in both TPS and MAP by 10% increments. possibly my adding AE at high MAP was not wise as was unwise adding 250% in TPS it is becoming clear the advantage of the Innovate WB. looking forwad to using it. soon. that will tell me what is really going on. i was just given the lag filter(accel enrich tps filter coefficient vs coolant temp) by TC this week and have not looked at it other than to read values (.18 or so @ 75 deg C or 175 F). still dont know what .18 means? should the LF spread out the AE over longer time if coolant cool on temp considering more fuel is wasted on plenum/runner walls? so low values of LF of .10 at low coolant temps is spreading out the time on? i seem to have to be careful(smooth accell/pedal) on open loop driving on low coolant temp in that the car will bog/stumble even more than when closed loop similar moderate driving. sorry still a bit confused.
By low engine speeds and flooding I am in the 800 to 1200 RPM range.
At 2000 to 2500 RPM a good amount of AE is required.
The TPS lag filter (LF) values is intended to extend the duration of the AE. It can also increase the magnitude of the AE. Same for the MAP LF table values.
If I am correct as to how TC computes the LF values, the smaller the value the greater the duration of AE. A slower LF will create a larger delta TPS which causes it to be extended in duration.
If the AE is OK at normal operating temperatures and not enough while cold then increase the AE vs Coolant table at those coolant areas of trouble.
The biggest problem is that the delta TPS AE PW table only goes to 25% delta TPS. For an engine being fed by 2" bore TBI(s) this table really needs to be doubled in size (to 50% delta TPS).
Else, at a true 25% delta TPS the AE is good, then at a true 50% delta TPS the AE is not enough. Then it can go the other way, rich AE at 25% delta and OK at 50% delta.
I've found that it is a real balancing act to get the AE all worked out. I ended up doubling the size of the delta TPS% PW AE table (to 50% delta TPS), and adding an AE vs RPM compensation table. From about 1800 RPM down I taper off the total amount of AE.
RBob.
Ahhhhhh.. This is why my 383 with 2 x 2" TB's (crossfire) shows a lean spike on the WB when I crack it wide open....
I've only had my WB for a week and it has already shown up many little areas that need attention.. Now I just need a "SpeedReader" to implement a bigger TPS AE table.
I have a question. Why is MAP AE after TPS AE? I mean, is MAP AE set up to come in after by Coef Filter? I would think vacuum would drop as soon as throttle blades open. MAP AE is 0 to 80%. My engine idles @ 7" vacuum, im assuming my MAP AE is activating @ 60% off idle. Am i right?
I know this is an old thread, but it has helped me a bunch, I'm finally tuning AE and my first couple of logs gave me interesting results...to me any way. Is it possible to need no MAP based AE at all? I haven't done any detailed AE tuning yet, but since I have a large TBI and am flowing relatively high pressure fuel, I thought I'd try to completely zero out my MAP AE since decreasing it seemed to be where I was headed. I also decreased my TPS AE quite a bit, but changing that to zero didn't work very well, so I have roughly 50% of what I started with. It still ended up dipping the AFR to 12.5 with a small crack of the throttle. I have a VAFPR, so that could have something to do with it. Here's one of my very short logs with an example of what I'm talking about, so please tell me what you think.
I would say it is possible to have TPS-AE only with no MAP AE. Reason being the first Ebelbrock TBI conversions I read had no MAP based AE. But AE MAP is helpfull. Grumpy once commented that it is possible to have an AEMAP event with no AE TPS event. Like steady throttle cruise and then approaching and climbing a steep incline. That large increase in load will see the MAP increase significantly and suddenly and may trigger AE MAP. Past week when I swiched over to VAFPR I noticed if I accellerated slowly from say 5% TPS to 50% over a say 1/8 mile on level road my MAP would increase and my A/F shoots to 20/1 and I will say I needed more MAP-AE OR my VE tables in that area are weak. Add to it a 7.4L TB makes MAP -AE more necessary?
I didn't think of it like that. The tuning I was doing was in a flat parking lot, so I should hit some hills. It almost makes more sense to adjust the MAP without having the TPS involved. It might make things easier (?). That should take some of the "art form" out of tuning AE, you think?
now needs paint - badly, 79 Malibu classic with 91 L98, 4L60, 3.73 
