so how does the safc help u car to get fuel at full throtle? its impossible to change maf reading at full throtle but if u trick ecu not to read full throtle u would need to reprogram ecu to run difrent timing and fuel curve.only thing that makes u car run good is a fmu and afc helps to correct for the injectors.adding map sensor is not a bad idea.if u think afc can control fuel under full throtle try to take out fmu and run 3 psi and ck u egt's.mine friend was working on a dohc ecu from 92 mazda protege and we were able to read stock chip and we had changet to e prom but there is no room to play with it and i seen the tables of timing advance and othe r ones and trust me u dont want to use table that is programed for mid throtle and run boost on it.

 

How can it be "impossible" to change the VAF signal at WOT? The AFC doesn't know or care if the throttle pedal is on the floor. It still alters the VAF signal and causes the fuel supply to change at WOT.

If the ECU ignores the VAF signal at WOT, then why does my EGT and O2 signal change when I alter my S-AFC fuel settings? Simple, the ECU still uses the VAF signal and the different voltage signal causes an increase or decrease in fuel supply. Sure the AFC reduces injector pulse while cruising and idling but that doesn't mean it won't fine tune fuel at WOT.

The FMU is not the reason my engine runs well. My engine runs at 38 psi fuel pressure at 0 vacuum which puts me around 53 psi at 15 psi boost using the OEM FPR (1:1). My FMU rate of gain is turned down and max pressure is only a little higher at 60-70 psi. Check out some older Miata turbo setups that only used an FMU. They ran 100-120 psi fuel pressure under boost. I would remove the FMU if I hadn't cut the OEM return line. BTW, I have a friend in Florida that ran 8 psi using an AFC and 460cc injectors with NO FMU till he bought an aftermarket ECU.

I'm not trying to attack you, just disproving these false myths you are spreading. Check the Mazda engine control manuals or install an AFC and larger injectors and you'll see for yourself that you are wrong about the ECU ignoring the VAF signal at WOT.

Jess Dillow -the one PseudoRealityX spoke of in the second post under this topic)

 

 

yes afc dont care if it sees full throtle it will change signal going to ecu but ecu wont do any thing.i see from u signature that u have 95 egt and that might be difrent but i know that 91 to 94 dohc ecu on mazda protege its not using vaf signal at full throtle.on gtx ecu vaf signal is at full throtle is used to calculate boost and if it opens more ecm will trriger fuel cut.I have safc on mine car and its now on gtx ecu and i had it on lx ecu on mine old setup.now im runing 18 psi and i have no fuel cut but before i put afc i had fuel cut at 8 psi just because i have biger turbo than gtx and flaper opens more as more air goeis trough vaf. what i did i took some fuel out over 90% throtle and that why ecu thinks im runig stock boost setings.and im not sure about 95 egt but i think it uses maf not vaf i might be wrong on that.if u car would have maf it would be complete difrent story.and another thing if u have 5 spd egt and u got a tps from auto how u stock ecu knows if u have 0 or 100 % throtle?

 

If anybody, including Chris, wants me to email them the page that was scanned showing engine operating strategies, email me at sherluck13@hotmail.com. I'd post the image but attachments are disabled. You just don't get it. I have printed proof FROM MAZDA'S OWN DIAGNOSTIC MANUAL showing the ECU pays attention to engine temperature (ACT, ECT), TPS signal, and VAF voltage at WOT. How else would it know how warm/cold the engine is, how much air is entering, and when the TPS leaves the WOT position. The ECU goes into Open loop to a preprogrammed set of maps but that doesn't mean there is only one map or the other variables can't alter the end product. Let me send you the MESC-I Control Strategies page and you will see you are WRONG! Believe what you will.

The 1991-95 EGT is OBD-I and uses the same engine, ECU, and VAF as a 1990-94 Protege LX. There are NO differences. Maybe you were trying to add fuel using original injectors and that is impossible. When the VAF door opens, it sends a voltage close to 0.0 volts. The AFC doesn't have much room to lower that voltage and richen OEM injectors. With larger injectors, you can reduce injector pulse length by having the AFC increase VAF voltage thus fooling the ECU into running a leaner mixture. The AFC will never do much in the positive % to add fuel.

My car doesn't have a 4-wire TPS from an auto car. That was my first attempt in getting the AFC to run better with the turbo but it didn't work as well as I had hoped. The TPS output was sent to the AFC, not the ECU. I reinstalled the 3-wire TPS and a MAP to control the AFC and found it works very well.

I'm done trying to understand your poorly written posts and show you the light. Maybe if you request the picture of MECS-I control strategies, you'll see the truth.

Jess
P.S. Do u talk like u write and spel or u just cool/laZy?

 

I dont think u understand what u write.If ecu gets signal from full open throtle switch it goes in to open loop and uses all the sensors exept vaf.If ecu dont get the signal from full open throtle switch it uses all the sensors to calculte fuel and timing.

 

Don't try to understand something you can't understand. I've dealt with Jess many times on his buildup of the car and he knows his **** when it comes to the S-AFC and the stock ECU.

Do some research on fuel and ignition systems and the stock ecu before you preach to the choir.

 

I understand perfectly! You are fighting a lost battle.

Chris said:
"If ecu gets signal from full open throtle switch it goes in to open loop and uses all the sensors exept vaf".

WRONG, WRONG, WRONG!!!!

"If ecu dont get the signal from full open throtle switch it uses all the sensors to calculte fuel and timing"

Correct. My engine and ECU are operating as designed with a 3-wire (manual) TPS and OEM VAF sending their normal signals to the ECU. The only difference is larger injectors and the AFC altering the VAF signal. Maybe you didn't pay enough attention or know what you were doing when you first installed the AFC on your LX ECU.

Get it right, the ECU uses the VAF signal to alter the preprogrammed fuel/ignition tables at WOT. Does the ECU inject the same amount of fuel at WOT on a cold engine as a hot engine? NO! WHY??? Because the ECU watches the ECT and ACT sensors and richens the mixture on a cold engine. Same goes for the VAF.

Over and OUT!
Jess

 

Are there any ECU (PCM) upgrades for the Protegé?
Piggy back systems are available to wire in to a stock ECU such as an
APEXi S-AFC. These systems will not work effectively due to Mazda's ECU
designs. At normal partial throttle operations, the AFC units will7
successfully fool the ECU to supply a different air/fuel mixture. However,
at full throttle, the ECU has it's own presets to override whatever input
data is sent. The only solution to this is to get a complete aftermarket
ECU replacement, such as an Haltech. Which is the ideal ECU for the BPT engine.


this is straigt from protegeFAQ i wuld recomed reading that

 

"this is straigt from protegeFAQ i wuld recomed reading that"

I recommend you stop believing everything you read and hear and take some spelling or typing classes! That information is incorrect for the 1990-1994 ECU. SOME, but not ALL inputs are ignored at WOT. No input is "overridden". I hope an administrator reads this conversation and updates that misleading information!

Follow the link pasted below. Click on "My Photos", then click "MECS-I E...", then click "Full Size" and look at line 7 in the table. It shows WOT fuel control is open loop and uses WOT lookup tables. PLURAL! Now look at the active sensors. VAF is included. The ECU uses the active sensors to determine which preprogrammed fuel table to use. You make it sound like there is only one table and the ECU blindly accesses it at WOT. Like I said before. The active sensors are variables that affect the fuel outcome. What about the well known trick of adding a resisitor to the ACT or ECT circuit and fooling the ECU into running richer?
If that works at WOT, how can you say altering the VAF voltage will not add/subtract fuel?

What are you going to believe? A blanket statement in the protegeFAQ that contains no detailed info and probably hasn't been well researched, or information taken directly from a Mazda tech manual? My own tuning of the S-AFC shows the manual to be correct. Changing VAF voltage at WOT changes fueling!

Here is the link:
http://photos.yahoo.com/sherluck13

Who will the masses believe? Your barely coherent posts with no support or my clearly defined, informative posts? I have obviously researched the 1990-1994 OBD-I, Mazda ECU and have almost three years experience with the S-AFC using OEM injectors, 330cc GTX injectors, and finally RX7 460cc injectors (all plug and play).

Jess
BTW, thanks Braden for your support.

 

http://www.brownsword.ca/ecucoding.html
If u look at the link it explains also that that vaf is not used at full throtle and i would say thte the person who wrote that knows his stuff beacuse he's reprograming his own ecu.its about ford probe gt but the car has very close design of ecu as mazda protege or egt.if it works for u im very happy. it dont work for me and couple difren people i talked with so i dont care. i tried to share information that i know.
BTW i also got over 3 years experince with SAFC

 

You are close but still not right.

He says "Over the last year and a half I have spent a considerable amount of my spare time poking around at the code and data located in the ROM of my '93 Ford Probe GT. This car's engine is the Mazda KLD engine, and its engine management is handled by the Mazda MECS-II system".

Do you now see? The 1990-94 Mazda ECU for the 1.8 BP uses MECS-I You are talking about a totally different ECU that uses different control strategies. You are saying something similar to OBD-I is the same as OBD-II.

Do you understand now?

Jess
P.S. I don't use a 4-wire TPS. I reverted back to the original 3-wire TPS. Everything is stock except the VAF signal is being altered by the AFC and timing altered by an MSD boost retard unit.

 

Read what the link you posted says further down the page:

" My car is a '93 Ford Probe GT, and therefore has OBD-I. I have done all my work on this ECU. The '96-'97 OBD-II KLD has a completely different ECU which is considerably more complex. As a result I know nothing about these newer ECU's and none of my work is likely to apply to them. "

 

Protege has OBD I ecu. he sid that OBD II ecu is difrent from OBD-I

 

That guy is programming his OBD-I ECU but it is a V6 ECU which uses MECS-II (Mazda engine control strageties-version two). Mazda's 4-cylinder ECU uses MECS-I

http://www.geocities.com/MotorCity/Downs/8175/tech.htm

Apples to oranges when it comes to engine control strategies.

Jess