Ok folks here it is. Im sitting down tonight to write this very long winded and overdrawn but much needed article for all of you maf users. Lets get started. Ok when looking at which code to use the $6e seems to be the best option if you dont mind its inflexibility towards specifing injetor pulse width time.With that said its time to dispell some myths and annoying peices of fiction. first of all the MAF tables are not what they appear to be. they are simply the equation to state. (note in the $32 $32b code) maf input FQ in MGHZ = grams of air per second. here is a picture of the table. in question this is MAF table 1 form tunercat's $32b tdf. The only time i would actuall touch this table was if the MAF had been altered or modified in a way that would create flow variances that would make tunning the Injector pulewidth table a nightmare. ie a big drop off in FQ at a given flow. to help aviod this issue i would suggest what ever you may do to your MAF sensor KEEP THE SCREENS.

If you have modified your MAF engine and find yourself lean or rich then its time to start working here. this is the BPW FUEL vs LOAD, msec of inj PW. this is where the magic of tuning for driveability come into play. the facotry map is flat and straight and really sucks. i dont understand how they ever made this thing work unless the expected airlfow at any given RPM to be constant. and that the engine would burn fuel in the same manner at all RPM ranges. this whole notion is just insane. this table is the whole key to tunning your maf car. without it your just getting no where. i find the best tunning mehtod to do this is note various BLM and INT readings at all load levels and RPM's and make percentage based changes. if i have an


INT of 108

and a BLM of 100

it a pretty good geuss that the engine is roughly 5% rich. at a given rpm. now this is table and it will need alot of work for a modded car.

ok now that we understand how the MAF tables function and how the ecm determines fueling at given load it time to discuss timing.Leave the stock base timming alone. do all work in this table. this is your part throttle table and its even refernced the for WOT.Just like the BPW fueling table this table is the basis for all WOT actions.

Now that weve covered what to tune what are we tunning for ??? im not as anal as some of our members here and thats a personall choice. i like to see teh BLM's and INT's in the 124-130 range. i have come to the realazation that given weather load and barometer that getting a perfect 128/128 tune form maf is just not worth the effort. even teh factory calbartions will wander a good bit form the 128/128 model. So you ask your self i have my PT tune about great now what. its time to take ont eh task of tunning for PE and AE. well how do i do it. heres how. this table shows the amount of calculated change to the fueling at WOT.this talbe works in percentages so there a bit of a fudge factor.based on ijecotr size and airflow of the engine the actuall delivered % of extra fuel in term of AF ratio will be different car to car the name of this table is WOT % chnage to AF ratio at WOT vs RPM.

now there is another table that similar to the one above that i will mention simply for the sake of mentioning. its the same table but it say WOT % change to AF versus COOLANT temp. now this is a wonderful table for people who dont let there cars warm up or run at the dragstrip at ller engine temps. but i will nto get into the specifics of this unless anyone asks. ok onto the next table the AE table. now that youve got the WOT AF ratio where you want it and the PT cruising is great its tme to fix that BOG when you nail the throttle. heres the table.the table name is

ACCEL enrich %bpw vs Asncy pulse

the basic job of this table is to give you a accelerator pumpshot. of sorts.

ok so now that we have a good bit of injetcor pulse width added for smacking the loud pedal open we need to figure out how long to add the extra fuel. this is critical in cars with big cams that need to build engine speed to gian air flow velocity to help atomize fuel.so if you have no bog off idle but the engine feels like it just need a bit longer pump shot heres the table.

also this tbale name is

# of accel enrich pulse vs engine coolant temp.

ok thats enough for one night off to bed i go. i will continue on with more if you ask. i figured i would simply cover the basics to get those who are scrathing there heads a little leg up.as for injetcor size look int eh constants table. and remeber that the injecotr pulses widths are halved becuase this ecm code uses a double fire. it fires on the rising and trailing edges of the ref pulse. and when viewed with a scanner divide the pulse width by 2 and look at the airlfow. if it doenst match your specifed commanded pulse width in yr table then look at BLM and INT how far are they off. if there way out there away form 128 then yeah its not gonna look right. the closer your tune the closer the injector Pulswe width will be to what you specified in the injector pulsewdith table.

have a good night. if anyone cares to add please do.

hey looks to be the start of a pretty sweet article series u got going here :-) Im not a MAF guy(got 2 SD cars and tune them) but boy oh boy are u gonna be the MAF guys new best friend :-)
Nice to see a MAF series along the lines of Trax's SD articles
nice work
later
PS keep it coming whenu get a chance cause a lot of MAF does relate to SD and vice versa :-)

Only one detail, thirdgen MAF sensors dont report to the ECM in frequency, thats an old leftover from the earlier systems that did use it.

its ok about the FQ thing becuase it dones really matter what the maf ouput is. its just the maf table are used to calbrate it.i also forgot something in using the pulswidth tunning method only a small oversight on my part. there a switch in teh ecm swtichs table that need to be turned off to use the MAF injetcor pulsewidth table. heres the switch table. its the next to last swtich down. basically it allows you to use the pulse wdith table.


make sure to unswitch it. or the tunnig will never work.

Funstick,

Do you know what the switch is labeled in Winbin in order to activate that table?

:hail: Very good article!!!!Particularly the switching and unswitching(I have altered those tables before with no response.
If i'm reading correctly I am to unswitch,make alterations and leave it unswitched? Also out of curiousity,if that is true what would results of leaving unswitched and not making any alterations, where would the ecm get it's bpw from??? Once again thanks for the great info!!!!

leave the swtich unswicthed as long as you prefer to use the maf pw table. the injetor bpw is calculated off of LV8 and injector size. LV8 is a combination function of RPM&AIRFLOW. the ecm uses this with the injector size to arrive at injector pulse width. if you ask me id rather specify the actuall injector pulsewdith my self. if anyone would like to add more please do.

could someone make this sticky ??? thanx

What!!! this is'nt a sticky yet?Using this info is the first time I could tune my car with the constants matching what is in the car.
Before to get blm/int somewhat close required lowering the constants 7 lb. below actual.

please do add what you learn here. im always looking for tips tricks etc. have a good one guys glad to help.

well its time to add some more to the condrum off stuff so far posted. i was working on a 302 ecm today and no matter how much fuel i plugged in it just would richen up at idle. now me being fustrtaed i walked away from the truck and something struck me as funny. the headlights were really dim. now your thinking dim head lights big deal right no not a little affair for sure. it turns out the truck was idleing with a charging volatge of 9.7 volts. now the way to solve this was to use a alternator pulley that was a bit smaller. at first i tried tunning this table beow but got nowehre as there wasnt enough voltage to sustain the extra pulsewdith. this is a warning to all those who are fitting a lean idle. this is the PW corection vs battery voltage table. i know it doenst seem like a big deal but fighting with a bad charging system will make you go crazy.

Hey man, good stuff you got going here.
Question for you as I am having some serious lean when I tip the throttle in which is AE related.

I have increased the "Acceleration Enrichment Factor vs. Change in LV8" considerably in the 0,64,128 LV8 range with no results.

Then I noticed the articles where you have the "Accel. Enrich %BPW Factor vs. Async Pulse". So in this table do I need to increase the values or decrease them for a richer Pump Shot??

Then in this table "No. of Accel. Enrich Async Pulses vs. Coolant Temp." again increase to lengthen the shot or decrease to lengthen it??

I think that when you give the explanation of these tables you should give examples of increase/decrease results of the represented values.

Thanks buddy,

Brian P

give me a day to double check everything then i will have a very firm answer ,hows the rest of the fuel tunning.

ok went out and played with my emulator to got a firm answer.

Accel. Enrich %BPW Factor vs. Async Pulse need to be increased.
this will ad a bigger pumpshot.


No. of Accel. Enrich Async Pulses vs. Coolant Temp.
this will if the values are increased make the pump shot longer.

Well the rest of the fuel tuning is better all except for BLM cell 6, I'm a bit rich here with BLM 122-124. I'm using the $6E as a base image. I love the S/A and other stuff that the others don't seem to give me. Open Loop fueling is for crap, I can watch it on the scanner go way lean (80-90mV's) and stay there until I hit Closed Loop operation. But it sucks in Open Loop becuase the idle is choppy and I have to feather the throttle so it doesn't die on me. I've adjusted/increased the values in the Open Loop AFR % Change vs. Coolant Temp with no success here. Wished I had this INJ PW vs. LV8 table to modify, tuning would be a cinch. I'd like to get a more predictable fueling curve.

AE is the biggest Pain In my A*s right now. When I nail the throttle the scanner shows a deep lean 80-110mV's for a full 2 seconds until the ECM compensates. I've adjusted the Min. LV8 to enable AE, Delta %TPS to enable AE (currently .39%), and the AE vs change in LV8 tables with no success (table looks like 40,40,40,50,50 at the corresponding 0,64,128,196,255 LV8's). Hence the questions about AE.

Any hints as to how to make the $6E's fueling more predictable?? I'm thinking I may grab this $32 bin and replicate the features I like about ARAP (Namely S/A) in it just to get more tunability over the fueling curve. Does this $32 bin work in 89 1227165 ECMs and can it be modded using a known .ecu for WinBin?

Thanks for the help thus far, keep it coming we MAF guys have degradation without representation around here ;-)

Brian P

I know this is a retarded question but what is the $32 code? What was it for??

I'm wondering if the stock 89 TPI IROC-Z w/ 350c.i, Auto Trans, 3.27 rear Eprom has this INJ PW vs. LV8 table in WinBin?

Brian P

$32 $32b are 86 and 87-88 respectively. they will work in a 89 ecms im jst dont know about the fan swithc being normaly open normally close ordeal. other than that it should be a cinch to tune.

ok an update for guys using the $32 $32b. tunercat has added a switch that wasnt in the original tdf thats currently avaible. if you email them im sure they will send otu the update. they added cylinder select for the guys swapping a v6 for a v8. also they added a swtich for you tranny swappers if you go from auto to manual or vise versa. it allows you to select auto or manual tranny logic which im sure has an effect on IAC behavior. good luck. just trying to keep things posted.

funstick,I have the new one(on cyl. select) I was told to put o in there(what was in there from the start,and started the car) why not 8?

o =8. i dont know why exactly but it does. thats it.

Just to clarify-if you uncheck the base pulse width calibration method in the ecm switch table; then you use for pump shot-accel enrich %bpw vs async pulse instead of lv8 accell enrich factor vs delta lv8?
Also has anyone tried to increase pump shot by decreasing the inj. flow rate(double fire) under ecm constants?
I do like the idea that the bpw table goes to 6400rpm...

89 cars dont have a cold start injector, so you would need to do something about that before you just throw an 87-88 code in there, otherwise it wont start well.

But tunercat now has crank fuel pulse width vs temp and crank fuel pulse width multiplier vs refernce pulses in the 32B-so you can adjust it same as the 6E!

i dont like coldstart injector they suck. the real issue is vaporizing the fuel when the engine is cold. the engine doesnt do this well thats why its needs so mych extra feul.

Funstick,

Would you mind emailing me the $32/$32b .bin and if you have it, the .ecu file for it as well?? I don't know which is for the auto tranny that I need. This will be used on an 89 car...do you have any suggestions?

Email addy is sena@team.camaroz28.com

Thanks,

hmmm theres a good bin but im not a home. when i get down to my house again next week ill email it to you.

also on a side note im working on a LEAN fuel mode highway patch for the 32 32b users. i figure this will once and for all settle up the issue of which code is better.. any boody would like to help on this much apprciated.

Lookin' good man!

TIA!

ok i need help form the coders here. i think i have found all the code involved in the highway spark mode. what i need help with is implementing it into the $32b. anytakers. ??

any luck getting the highway mode into the $32 ecu? i want to use the $32/$32B which do i need for use in my 89 Iroc 350TPI 3.73 posi rear auto trani? running really rich, grumpy suggested tuning with the MAF tables instead of the injector constant, and it appera this would be easier with the $32/$32b ecu's

i persoannly lack the coding ability to slip the highway fuel mode in. however with a pretty hot combo your gas milegae is gonna suck anyways. as for tunnign with maf tables leave them alone use the inj pw vs lv8 table the 3d fuel table. much better way to tune. the only way i would touch the maf table was if i moded the maf and then wantd to fix some flow variations.

running bone stock, and maf hasnt been touched, so use the injector constant wierd, in another thread Grumpy statedso iwas confused because in alot of other threads Grumpy yells at people for playing with the MAF table.

youe best bet is to go ahead and take what ever advice you feel will get you the best results with minimal headaches. if i was in your shoes i would look at $32b. no need for the injector constant the fueling is very striaght forward. what ever you spec in the LV8 vs Inj PW table is what it spits out. just note the lv8,rpm and BLM int and make adjustment accordingly. take alot of geuss work out. still if you need help do feel free to email me.

Bruce tend to yell at lots of people. in fact his MAF recalibration article in the stickys makes little to no sense to me or anyone else for that matter( this lead to my delving into the maf). i think bruce is a very capable indiviual but his ability to communicate effectively the information he trys to share is lacking. id say at best bruce simply fails to properly articullate that which he trys to convey.

caleb if you find yourself needing help drop me mail.

funstick,

Up to this point, I have tried to tune my $32B ECM by altering the fuel injector table, mainly to get the BLMs in line.

However, while tuning the PCM in my '99 car where I modified the MAF sensor (ported nylon ends and removed screens), I realized that I had to re-calibrate the MAF table because the MAF was under-reporting the amount of air going into the engine. The LTFTs (BLMs) were out of wack. The engine was getting the same amount of air, but the MAF was reporting less air, and the PCM calculated too little fuel, which resulted in a lean condition and the PCM learned stuff (LTFT, Long Term Fuel Trim) kicks in and the PCM ends up adding fuel thru the LFTF value function. When I modified the MAF table values, I re-calibrated the MAF and brought the LTFTs down to 0%, same as the BLM at 128.

So I agree with Grumpy on this point. We should put in the most accurate fuel injector flow rate as we know it to be and modify the MAF table to bring the BLM into line. This case is for when the factory MAF has been modified.

This process worked very well on my '99 car, it should also work well on my '87 car. But the '87 code has a problem with a limitation of 5 volts (255 gms/sec). But as discussed in the other thread, I think that I can overcome this issue.

Recall that I stated in the other thread that my '99 engine flows a max of 320 gms/sec. I think that maybe the fix is to send the ECM into WOT mode before the flow exceeds 255 gms/sec. There is a WOT table which sets when the ECM is to go into the WOT mode (PE Mode).

I have descreened my '87 MAF to improve the top end air flow potential. So, the MAF table should be re-calibrated. The process of re-calibrating the MAF table is alot of runs on the street in orcer to capture all fuel/BLM cells that are involved in the $32B ECM, I think 16. We need to match engine RPM and the BLM cells to specific locations in the MAF table.

Anyway, this is my honest opinion on this matter.

ive stated this before as long as you command a given inj pulsewidth vs lv8 the ecm will fire based upon that. did you uncheck the switch to turn off calculated method? if not then it wont use the table.

In the switch table, there is an 'x' in the base PW cal method box.

So what does this mean?

There is the PW table which is RPM vs lv8 vs PW that I have been tuning. Will this table be used or not?

doc you need to switch the x off to use the lv8 vs rpm vs pw table. if youve made zero progress this coulds be why.

x needs to be switched to 0

There were people improperly editing, and needlessly editing them.

grumpy i agree with you there. i think at the start of this article i stated that you should leave the maf table alone unless you modify the maf. the only real point of modding the maf table is to relinearize it.

Okay, i again am confused, maybe just dumb. But in another one of my threads, Grumpy said set the injector canstant to what they really were, and then tune with the MAF tables, but funstick says only to tune with the MAF tables if you have modified your MAF, which I havent done, so where do i start?

I have yet to yell at anyone.
I just get tired of correcting some of the nonsense you post.

If you don't get it, ask a guestion, what is so hard about that?. This verbal attack in a thread I just so happened to have been ignoring is just about as classless of item that I might expect from you. Pity you don't spend your time trying to get a grasp on proms rather then going out of your way to verbally belittle my work.

You can't even be bothered to read for more then an hour in the DIY archives, to research something, and then want folks to drop the info in your lap.

I do write in a manner to provoke the reader to THINK, and that's probably what you don't like. if you were to really read and try to understand what I'd written, I answered how to get around the MAF limitiations. Oh, but that might take some thinking and thought. No birdies flying around whispering to you....

i should have made myself a bit more clear. i was reffering to table mods for $32 $32b. with $6e its almost a pure nesscaity becuase the code is so locked. with $6e im almost of the mind that lying about the injector constant IE under reporting it might be a better way to tune. this way you can bring the maf table entires down to lower values. it always easy to get plenty of fuel out of the $6e but then people hit that code wall. i dont know what is the truly best way to tune with $6e. ive been doing a bit of research on teh subject and so far its been alot of maybe and what ifs. when i get a definitive way to tune with $6e ill post it until then its just more speculation and conjecture.

bruce its not a personal attack. at no point have i ever accused you of not knowing you stuff. i have a hard time grasping what you write alot of times. i have no idea why. ive had various emails conversations about it with other people and some things you write are truly amazing but alot of the replys you give leave the reader deluded and more confused. i am glad to see however that youve been changing alot of how you present yourself. iv never disliked you. just the way you approach the subject. its as if you almost like to be difficult. again it wasnt a personal attack it was just they way i felt about what you posted about maf until just very recently. ive acutally been enjoying the input. so if youd like to stop the verbal warfare fine i would be glad to do so. i think we both have something to put on the table.

and as for not asking questions i do ask them but mostly i keep learning reading etc. i find most of my answer execpt for hardware stuff ( im still an EE dummy) buy just reading experimenting.

yet again lets call and end to this whole war of words.

Oh really?.
Yet again you slight what I've had to say, and ask for no clarification, of what you don't understand.

Do me and yourself a favor, and just leave me out of your posts. Can you at least understand that?.
I was just fine with you having your lil thread here, but you had to drag me into it.
If you were accurate with your posts you'd seldom even hear from me.

And I see no one has gotten any further with the limits of the stock MAFs.

there not much to be had with stock mafs. there either needs to be a consensus to use bigger MAF like the bosch 90mm unit found in the M5 or use a lt1 maf with a translator.however i dont think alot of guys are gonna do it. why when a map sensor and a used ecm cost about $50 ??

Well, again if you were to research the subject matter instead of hitting reply you would have found option 3. Which is how to recal the stocker to better suit the higher HP applications.

Let me know where to send you, a check, to supply a 3 bar MAP sensor and a 1227148 ecm, both for $50.