I have just fired up the 383 in my IROC.

Specs

6E code MAF starting with ARAP bin
383
AFR 190s
224/230 Comp Cam
6 spd trans.

I've tuned several engines in the past but am shadetree compared to most of you guys. This is the first engine that I can't richen up enough by just adjusting the MAF Tables.

I need to change the boundaries for the MAF 1-6 tables....so I'm guessing its time to head to the dreaded MAF scalars that I've never futzed with before.

I do not have a wideband installed yet...but it is sure looks nice sitting in the passenger seat of the car. I bought the INNOVATE LC1 I believe is the nomenclature last week from Moates along with a new ALDL Extreme cable to replace my old Mattei cable.

Right now to drive it I have adjusted the Inj Constant to about 28 lbs for my 30 lb injectors and it has the fuel close enough for the computer to get it the rest of the way. It only has 100 miles on it, so I'm not out doing any WOT passes yet.

SO, long winded lead in to MAF scalars.

My understanding is you tweak them 1 or 2 clicks up to richen it up...go for a datalogging run...check your BLMs to see if it was adjusted enough...go back, up them again...to get it close. Then when you get it to where its close, you go back and adjust the MAF Airflow tables. Or is the prefered way to lock your BLMs at 128 and tune to the AFR?


I've always just tried to tune to 128 BLM and been done...never locked blms or tuned open loop.

Thanks in Advance...

 

There is good MAF tuning information in the Tuning Guide Book in the sticky's. Check chapter 5 for the '7165 ECM. One thing I recall is that if you change the scalar and values for one table. The adjoining tables need to be tweaked. This is to provide a smooth transition from one table to the next.

RBob.

 

I've read through that tuning guide a couple of times but it doesn't make a lot of sense to me. Let me read through it again with fresh eyes and maybe it will become clearer to me...

Thanks,

 

I am playing with the 6E right now also with tunerpro rt and autoprom. Hopefully this sheds a little light for you. The scalars just scale or multiply up or down the low and high limits of each maf table section. So if one table needs more gm/s than is allowed (you have reached the high limit) you change the scalar to allow a larger value. This will cause a discontinuity in the curve or a vertical jump where it connects to the next tables curve, this is why you have to adjust the adjoining/neighboring tables to produce a smooth curve. You may have to reread the stickies a few more times, learning curve varies for everyone.

Now don't forget about you max airflow vs rpm table that will need to be adjusted since you have a top end that will actually move some air now. This table is meant for a stock engine more or less so just move those values up so it won't cap your airflow calcs.

You may also want to look at the pw cap on commanded afr over 11:1. I haven't found a definitive answer yet but the older 165 maf code, before the $6E, had a code limitation when the commanded afr went over 11:1 the calc would overflow and limit pulse width to the injectors. I think the $6E still suffers from this because I appear to have this happening right now on my engine. It may also involve the injector constants of higher values than 22 lb/hr.

Now the debate of how to tune, I think most people including myself will tell you to lock in open loop and tune with wideband. This should get you 95% there pretty fast, then tune into closed loop after you get your baseline looking good open loop.

This is just my opinion, good luck with your project. There alot of good info on the forum.

 

You can richen it up also by "lieing" to the computer and putting a smaller number for fuel injector constant in as well. All depends on how you want to do it. On my 406 with 32lb injectors I got it close by tweaking that constant then had to do a lot less work with the MAF tables and scalars. Ended up going with 25lbs there and then had to take some fuel out of the PE tables. With very little work on the MAF tables after that I was running 128 BLMs all day long.

 

I've made good progress so far with the WB02. I ticked the MAF Scalars up 1 pt and it seems like that did the trick to get the lower 3 maf tables in scale. I didn't mess with the upper 3 tables. They are OK so far.

I'm still trying to reign in the A/F ratio...but am making progress. I'm running 100% in open loop right now. truth be told, car runs better than it ever has in open loop! I think I need to change my factory 02 if I ever go back to it.

Anyway...I have a lean area of the map...about 2000 rpm, light load, light throttle, but trying to accelerate... car goes to like 22:1 and just flat falls on its face. I have looked at the MAF tables and its not any blip in there. I just can't figure it out. I did a quick search and am still trying to find if anyone has had this problem before. Near as I can tell, it goes lean for no apparent reason...

Anyone have any words of wisdom?

As a side note...my spark tables I smoothed out years ago to be less blocky and more of a smooth transition. They haven't failed me yet...but maybe this has something to do with it?

 

This is a quick reply post. Open loop allows for a richer AFR to be used. Which provides better throttle response. The other side of the coin is lack of mileage and emissions compliance. No reply required.

Most likely injector compensation values. They make a difference and are used to compensate for opening & closing times. If the MAF and intake tract is basically stock, then adjust the injector compensation in those areas to compensate.

Then go back to the MAF tables for final tuning.

RBob.

 

I was searching around and found this post...

https://www.thirdgen.org/forums/diy-...ery-light.html

Sounds like what you are telling me Rbob....I am trying to find this in Tunerpro RT...but am thinking it may not be defined or I'm too tired right now to translate it to Tunerpro language. Do you know if is defined there?

 

I think he means battery compensation table. Correct me if I am wrong.

I also just wanted to say I have the same issue. But I am too busy with school right now to experiment. My biggest issue is with the lean spot like you are describing is only at lower engine revs. Mainly from idle to around 2000 rpms higher up theres really no issue with on and off or light load transitions.

 

Last post of that thread has it. The small PW compensation tables. Can also add to the battery compensation tables for injectors that take longer to open overall.

Not sure what these tables are in the XDF.

RBob.

 

In my XDF you have "Injector Pulse Width Correction for low Pulse Width" and "Injector Pulse Width Correction vs. Battery Voltage" in the tables that might be helpful for this. You might also play with the "Default air flow offset per g/sec vs RPM".

 

Wow. I'm having the same issue. I'm using $32b though. I can't find some of the things their talking about.

 

That one sounds like it is for creating a default value when the MAF is deemed bad. If so it won't make any difference changing it unless the MAF input is being ignored. To tune it can unplug the MAF sensor to force the ECM to create a default airflow.

RBob.

 

Thanks for the info guys. I'll have to take a look this weekend.

I'm developing a question on WB 02 readings and their fluctuation...but I want to review it tonight and be sure I am seeing what I think I'm seeing.

I guess what I'm saying is expect to see more questions!

 

Just as a note so it isn't lost somewhere else as I didn't notice it in posts when first starting out.

Was seeing a odd change in AFR on the wideband. Sometimes it was perfect...sometimes it was lean....sometimes rich. Was thinking this magic wideband isn't making my life any easier.

So I thought 'wonder if something else is acting on the AFR in open loop and causing odd changes'.

Sure enough..did some searching during a long meeting and found that I never shut my open loop fuel adjustment vs coolant temp off...or 0'd it out at normal running conditions. So it was always adding fuel. When I 0'd it out at operating temp...schizzam...car went way lean. So now I basically get to start over. I see myself heading toward my MAF Scalars some more!

 

Check your "MAF High Diag. Error Threshold". Stock is set at 45 Grams/sec but if you are other than stock you need to set this value higher. Basically it is a setting for part throttle and knows the car (stock) should only flow a certain amount of air under a certain rpm. I don't remember the rpm. But my car was pulling a lot more than 45 Grams/sec and it would cause it to go to 22:1 on my WB and the motor would bog and then it would add run fine if I hit the accelerator more. I changed this setting to 65 Grams/sec and my problem disappered. I hope this helps.

 

Thanks for the tip.

I see it and it is set to 45...

 

With a data point of 1...I think sliding the MAF diagnostic to 65 solved my problem. I purposefully granny accelerated through the area where the car would have went way lean today on the way to work and it cruised through it fine.

I noticed last night when trying to rough in the fueling maps that when it went lean I caught a 43 gms/sec on the laptop screen...so I figured you may have been onto something and you were.

Thanks...I'm wondering if this has been whats been causing my lean problem for years when it feels like the Highway mode is kicking in.

I think I finally did my CAT completely in...though. It has been rattling a bit for years...but its making a huge amount of noise now...

 

As a general update...feel I'm finally making progress. After 0'ing out all of the tables for open loop fuel adder, I'm finally, I think...honing in on a reasonable fuel map. I haven't really messed with anything else yet...just tryin to keep it from running lean.

The MAF scalars, I had to bump up 4 or 5 clicks. Not completely sure as I just started sliding...driving...lean...sliding again...etc. So I hope I'm done with mucking with those. The upper ones may still need some. I focussed mainly on the casual driving ones.

Thanks for the help so far...

 

General Update again...for anyone that may care in the future.

Have been constantly upping the fuel. The MAF scalar's have been slid more like 4 or 5 in a lot of places down low...seems like more up high. Have the general driving area between 13.8-15 AFR. Trying to reign that in a bit more...but it seems like it can vary that much dependent on outside temp.

Started working more in the top of the map. Have the MAF table 6 completely maxed out now. Maxed out the scalar on the #5 table and have the top end of it to 254. Not sure if that's too rich or not(haven't tried it out since I did it)...but after a drive at lunch I was still pretty lean up at 188 gms...so figured it was time to just take the plunge. I'll see if I end up leaning that back out or not. That whole #5 table is up in the 'I'll never get there unless at WOT' most of the time...so really, just trying to get it close then move to PE adjustments. In retrospect...I can see maybe moving that back down some...we'll see.

I'm far from an expert...so if there are holes in anything I'm saying...speak up. I hope my aimless babbling about what I'm doing will help someone out with a MAF car in the future.

 

There is a chance that 383 of yours will hit the 254 limit at higher rpms above 4500 and WOT. You will need to go into PE %enrichment vs rpm to add fuel then.

I'm surprised you have to change the scalars THAT much to get it to run right. What bin are you starting with? I used my 89 AUJL bin and only had to change few spots in the first 2 tables to get idle and very light throttle/cruise correct, and after that the stock table 3-6 were fine air fuel wise. My 383 was HSR, AFR 195's, 230/245 cam .600+ lift. Just seems odd you have to scale it up that much to get the air fuel in open loop down to mid 14's or so.

 

Huh...thats an interesting comment. Thats why I put the actual math in as to how much I had to bump it in hopes for that kind of comment. Let me go look at each table to see how much they went up...

table 1: 4 clicks
table 2: 8 clicks
table 3: 7 clicks
table 4: 12 clicks
table 5: Its maxed out now all the way to FF

That is what Tunercat gave me for steps as I slid the slider. I just now noticed I could use the arrow keys and go in smaller intervals.

I started with the ARAP bin. I have it fairly well dialed in now. I have all of table 6 maxed out and hit 254 at the top of table 5.

Am I doing something wrong? Is there something else I could do? I am running stock fuel pressure and 30 lb injectors. Injector constant set properly. I think our engines are fairly similar...but yours had a much bigger cam.

I currently have PE shut off, running 100% in open loop. I am about ready to turn closed loop back on and move on to PE stuff...

Thoughts?

 

For the record...this did fix my problem with this little bit of the map.

 

I have a similar engine. 383, super-ram, 219 cam, CNC ported L98 AL heads. (the engine is an old-school Lingenfelter 383) Attached is my latest tune. I tried to get LPE to seel me their tune but they wouldn't so I did my own. You can compare my fuel and timing curves. I too had to crank up my maf scalars. I'd be interested in seeing yours as well. My car runs pretty well, no dyno numbers yet though. The only change I made was Comp Pro Magnum 1.6 rockers, Mahle forged pistons with 10.5:1 compression. LPE rates the engine at 440hp and 480ftlbs.

P.S. anyone else is welcome to look at this. Tell me if there is something terrible hiding in there...

P.S.S. gsf-87IROC, where in southern IN are you? I'm in South Bend...

 

I figured you used ARAP. I think ARAP's open loop fueling tables are less than AUJL's so maybe thats why you needed to scale the MAF's up so much to compensate. Also, since you have PE mode off, that is probably why you have to scale table 4-6 up soo much more than what I did, and even part of table 3 i guess. I left PE mode on and slowly tuned that for fueling but for the most part thats used under heavy throttle. My table 1-2 and low parts of table 3 I think are just mild to medium part throttle and I didnt have to change, however the open loop fueling tables probably added more fuel there over ARAP so that may be why i didnt have to scale my stuff.

I think you are doing it correctly. Let MAF control what it can and then use PE mode to give the extra bit of fuel you need.

I've tried my tune on many other similar motors from 383's to one 406 motor and none of them worked well with my tune. Weird, given the motors were similar, but my motor ran very hard with my tune. Go figure.

I found that my car maxed out the MAF by 4500-5000 rpm, somewhere in there so PE mode DRASTICALLY needed modded over stock. I added somewhere near 85% more fuel at 4500 rpm and it tapered off to about 65-70% by peak hp. Stock tables only add like 7% to 16% in those upper ranges

 

Thanks for the feedback.

I plan on turning PE back on...damn near got rear ended when I tried to get out in front of someone today on the way back from lunch. Needed gas...punched it...car about died! EGADS!

Anyway, I'm struggling from one drive cycle to the next to show repeatable results with the wideband. Not sure if its intake manifold temp swings dependent on heat soak or what. Anyway, I've got it very close and need to get new plug wires on the thing as I'm wondering if my old ones may be fried to the point I have a dead cylinder at times or something.

Overall, cars running well. I'll turn PE back on and start futzing with the pump shot and PE.

One question on PE. I had a -7% on the ARAP code in the PE vs RPM tables. I assume that means it was pulling 7% of fuel OUT and not adding fuel. This is an intuitive table, right?

Right now, without PE if I walk my way up to 225 gms/sec it is holding solid at 14.6:1 when I hold it there. I plan on doing the math to get to 12.75:1 from there and add that.

For what its worth. I get it up that high in gms/sec at about 5500 rpm with my foot mildly on the brake. Works like a charm!

Oh, one last PE question. Do you tune the Accel Enrich tables in open loop or closed loop...or does it matter?
Thanks!

 

Totally missed your post earlier...I'll take a look at your bin.

I am down in Columbus/Edinburgh south of Indy.

 

Yeah PE table is + for add, - for take out. ARAP takes out fuel for some reason. Just the way the bin is made. So positive numbers will add fuel.

You should be seeing some consistancy with the wideband air fuels unless your battery voltage is dropping, thus changing fuel or ignition problems may not be lighting off the cylinders well, or even exhaust leaks.

If i recall, I started at 17 to 1 air fuel at WOT. I added about 25-30% fuel up top over my base bin which already had 30-40% more fuel over stock, to get it near 13.0 to 1 air fuel. I had to add over 40% fuel over the 40% already in my base bin at peak torque to get air fuel down to mid 13's. I think stock fueling was 16% over 4800 rpm and 7% in the mid range. Base bin had 40% where the 16's were. Everything else was stock. between 3600-4400 I think i had to change that 7% to 70's-80s % just to get enough fuel. I'd have to look at my old bins

I left my MAF tables stock tho, so I could have tuned those first to see what I could get out of it but decided PE mode was much easier to do.

 

I do see consistancy I guess...but not from drive to drive...only during the same drive.

Does that make sense?

This morning on the way in to work...I had a 20 minute commute taking my daugther to daycare. I was PERFECT at around 14.7:1(+/-0.2 it seemed...maybe a touch more). Then, dropped her off...fired the car back up...short 5 minute commute into work idle, which had been rock solid at 14.6-14.7:1 was now at 15.0-15.3:1. Still reasonable...but then at lunch..it was still up about the same 15.0:1-15.3:1.

Difference between lunch and this morning...about 15-20^F. So the early am drive is probably more apples to apples. I'm going to datalog one last time on the way home tonight in open loop and check my numbers. We'll see what that says. I like to tune in the mid 70s outside. After this...if they are in a range of 14.0--15.0:1 or even 15.3:1...I'm going to calll it 'good' and move on for now. I have a broke cat to take care of as well as questionable spark plug wires...so I may be chasing my own tail trying to get it perfect. Gotta check the rest of the car first...I have enough grey hairs!

 

If you're doing all your tuning and leaving the car in open loop mode you're going to see that kind of swing with ambient temps changing. That is what the BLM and INT are for is changing ambient conditions. THis is also an area where you need to be careful with your WOT tuning. Since you're relying on PE for enrichment at WOT, you are no longer accounting for ambient conditions. My car is the same way. WOT in the morning might be 12.0:1, and WOT in the heat of august might be 13.2:1. I got a rude awakening last summer down in Bristol TN on the Power Tour at the drag strip. THE change in elevation and heat leaned me out to 14.0:1 and the car was spark knocking down the track so I short shifted and shut er down after 2 runs. The track was super busy or I would have richened the chip and made another pass but it just wasn't worth it at the time.

 

Thanks...

I have experience swinging BLMs depending on outside temp...so I have kind of expected that...just never worked directly with a WB02 and swinging AFRs. Now the thing is...this morning...the temp was the same under 2 drive cycles...with a change in the 02 readings...that is what I didn't expect. Thats why I was thinking it might be related to heat soak of the intake.

As for PE...Yah...not sure what you do about that.

I'll put it back in closed loop shortly if the 02 sensor can keep up. Its a pretty old 4 wire 4th gen one...put it on back in the late 90s...so its probably due for a change(it only has 40k miles on it with about 4 engines over the years. )

 

Tried putting it back in closed loop tonight and it ran OK at times...but I expected BLMs to hover around 128 or at least be close. Most of the time they were pegged at 108.

I didn't drive it veryr long like this...but at idle, it hit 19:1 a couple times...other times it was OK. Maybe this is the learn process? I didn't tihnk it did that before...but this tune could be so far off from factory it has to bounce around alot before it settles in?


Odd thing is...AFR was way lean on the WB02 and the BLMs were 108...is this maybe a 'rich' via the BLM and lean via the WB 02 because its trying to lean the car out and it takes a while for the BLMs to update? It just seemed odd. I think I need to put a new 02 sensor in it before I trust it too far.

Also turned PE back on and opened the car up for the first time with some WOT passes.

Damn is all I have to say. It ran good.

 

I never liked how open loop WB02 doesnt seem to match closed loop BLMs. I think it has somethign to do with the o2 settings and swing mv settings. I played with them to get blms to shift with same AFR readings on the WB02, but decided to just keep it open loop. My car ran ok in closed loop except right at warm startups. For about 20 seconds or so it would go stupid lean and want to stall out, then it would correct itself and run normal again.

I think it has something to do with o2 not getting warm enough to work, and the ecm is set to go into closed loop before the sensor is really ready. There are some timers to play with there but I never got it figured out.

As long as your MAF tables and PE curve is smooth, the wide band AFR should not swing drastically as rpms/loads change. Coolant temp offsets need to be controlled as well to prevent fuel swings.

 

FWIW I never tuned in open loop. I completely tuned the car in closed loop off my wideband. My wideband is right in my header collector and I have ceramic coated headers so it should be getting warm enough. Have you done a free air calibration on your WB02 recently?

Just for giggles, have you tried my .bin yet? Or at least compared my fuel tables to yours? I don't remember having this much trouble when I did mine but I didnt tune it in the same method.

 

The WB is about 3 weeks old and I free air cal'd it last week just to be sure it was right. I am pretty sure its accurate.

I haven't looked at your chip beyond comparing the scalars you tweaked to what I have tweaked. I can pop it in at some point and try it out after I check spark tables and such.

Orrr....what you describe about the 'stupid lean' is fairly accurate other than the fact it did it after a short drive with it when I stopped at a stop sign and left it sit and idle while I messed with something on the laptop.


I'd really like to get this thing back to closed loop as I want to be able to engage highway mode and try to get the fuel economy up out of the toilet where I'm sure its at now. :-) I'll keep playing around with it...probably be a good idea to replace the NB02 just to be sure its up to par...and probably outta check the heater circuit on it to be sure that I haven't unhooked it when I did my WB02 wiring(making mental to do list)...

 

Were you tuning on the fly? I never did this. My issue was only on startups. I'd start, it would be in open loop for a few seconds then transition to closed loop and go lean, pegging my guage at 18 to 1. It was probably leaner than that, closer to 19-20 but teh guage only registers 18.
I had to give it some gas to keep it alive. Then after 20 seconds or so of this, it would stabilize and go back to 14.5 to 1.

If you make changes on the fly there could be a chance the ecm needs updated and to learn after the new change was made, so the lean condition could be the result of that. I'd try to shut the car off and make a change then restart and go from there.

 

Yah, I wondered what the learning was going to do. After tuning in Open loop with the WB....I got used to instant changes. With the tuning and then going open loop...I may just need to get used to it for a bit. I'll put a new 02 in it and try it again at some point.

I have a major bog off the line right now I'm trying to fix...have to go off and search AE and PE...and what changes to make. I haven't studied those too much as I've been more worried about the other fuel tables.

 

For me the biggest AE tuner was the % AE enrichment versus change in LV8. Worked good. Dont need a whole lot over stock, just change the values alittle bit at a time to see what effect it has

 

I bumped those all up by 1.5X factor...but haven't had any time to really test it. I'll see. I expect, like a carb...if I put too much fuel in...I'll feel a bog before it takes off....of course, if I don't put enough fuel in...I'll feel a bog.

What am I looking for on the WB? It NOT going lean when I punch it....or am I looking for a instant start toward 12.75:1 or so?

I think the 1.5X helped...as it was shooting to 22:1 or so before...but only shoots to 18.5:1 or so now...but I can't really confirm that as I only kind of tested it once or twice.

 

it shouldnt shoot lean. You should feel no hesitation when you mash the gas.

 

im having a bit of a lean condition myself and seems to be like what your saying. weird thing is that it was running ok before in closed loop but now that my NTK 02 sensor decided to die 2 days ago (has less than 3000miles on it btw) ive decided to tune it in open loop. btw i have a 383 HSR with 195cc heads, XFI280 cam, 700r4 with 2900stall.

been using tunerpro RT and my LC-1 wideband, in closed loop i would run high 14 to 15:1's on my wideband at idle and when i mashed the gas it would flucuate 15-16:1s, my WOT was 11.4-12.4:1.

now without the 02 working i was idling like 15-16:1s, when give it gas (up to my stall of about 2700-3000) i lean out to 16-17.9:1s... some times i would get 18-19:1. then my PE would kick in and i would richen up and take off. ive added 2-2.5g to my MAF tables 1,2,3,4. my PE is 15% less than wat ORR89s tune is and my AE is the same as ORR89s which is about 18-24% in the 128 to 256 LV8 range. seems that the AE isnt doin much at all since once i step on the gas it goes lean, its in the 11-12:1 range when im on decel tho.

today i shut off closed loop (maxed out the temp for closed loop enable) i added alittle more to my MAF table 1 and and changed some of the AE perimeters and im now idling in the 12.5-13.5:1 range. but im still lean 16 to high 17:1s under throttle. now im even getting cutting out/hesitation when i get on it closer to full throttle and manual shifting.

ive found that increasing my MAF tables 2-4 hasnt really done much. PE vs RPM does control my WOT A/F. but i cant seem to get rid of my lean condition in the 2000-3000 range (my converter stall range). lean condition seems to be in the 15-88g MAF range, and in the 150-170LV8 range.

PE will kick in at a certain TPS/LV8 but u can lower this, prob is that PE will kick in sooner but at the cost of MPG. i did this which is why after like 3000ish the PE kicks in and i take off. My AE is the same as Orr89s but it doesnt seem to be enough since it goes instant lean from 13:1 to 16/17:1.

any ideas? also i dnt bother using the BLM/INT... mine seem to be wacked out, i tired to get them to the 128 but they never get close and the engine runs like poop. im just gona give the motor wat i wants. this motor only has 2000miles on it

 

x2, I slightly over-richen mine to fight burst spark knock and build torque. If you can keep the combustion temps down enough to prevent spark knock you'll be way ahead. If it knocks and you have to pull timing, you've got to pull LOTS of timing to get it to stop.

When I nail WOT, my WB swings right to 12.0 and leans to 12.7ish.

 

I started blindly messing with my AE Saturday night. Lots going on this weekend...so I wasn't thinking too clearly(daugthers 5th bday had 2 parties this weekend)...and I richened things up way too much.

Drove it to church Sunday..then on the way home, floored it getting on the interstate. Happened to look in the mirror and it was leaving a heavy trail of grey smoke behind me. So I went home and undid everything I had done...mostly...and started hitting it at more of a sensible approach after taking it out for a test drive to get some datalogs.

I richened WOT up some...but probably, after thinking about it...I need to lean it out up higher.

Its going on a dyno Thursday...so I will finish up the WOT tuning there I think. Going to focus on the AE mostly...so I'll be checkin back in with any questions.