Air/Fuel Controller Installed

[jdm monkey]

I just recently installed an APEXI Neo Air/Fuel controller in response to the $4+ gas price. I believe that our cars run rich from the factory. By controlling the Air Flow, I can lean out the mixture using less fuel and also probably gaining a few hp. I'm still waiting for my wideband O2 sensor so I can properly tune this thing. Wiring was straight forward. The only problem I ran across is that the Service Manual states that the MAF wire signal was yellow but actually, it was blue.
In the future, I will be using a more advanced piggy back for my turbo project.
I know you guys love pics....:
http://farm7.staticflickr.com/6235/7022236817_81095ba7eb_b.jpg
http://farm8.staticflickr.com/7078/6876135356_2e216e7e82_b.jpg
http://farm7.staticflickr.com/6034/6876136876_65983b94ae_b.jpg
http://farm8.staticflickr.com/7057/7022240627_4717fd33d2_b.jpg

[etlsport]

Looks/sounds good, but is it causing a CEL?

[jdm monkey]

No CEL. The CEL you see is for my IAT. I have an OBD II scanner.

[vxfocus]

wouldnt you need two wideband o2 sensors?one for each side either before or after the cats

[Robbomaz]

4 bux a gal hey? Buck sixty/litre here - $6.40/gall.....

[Vendetta]

Yeah, but you're not sitting on several gazillion barrels of the stuff.

(And the way this so-called "Administration" is handling our energy policies, you wouldn't think we were, either.)

-V

[89Vette]

Yeah, but you're not sitting on several gazillion barrels of the stuff.

(And the way this so-called "Administration" is handling our energy policies, you wouldn't think we were, either.)

-V

Could be. OTOH, what if the GUYS (vs guy) at the top were really convinced we were on the cusp of environmental disaster (global warming) as a result of the carbon emissions.

If they (all government) really felt that way, it might be easiest to force consumers into more efficient (lower emissions) vehicles by letting the price of fuel go up.

Also, remember any reduction in prices as a result of the release of reserves would be short-lived. So, any (yes, ANY) president looking to easy this issue before an election might wait until closer to election time before instituting such measures.

(If you couldn't tell, I'm prejudiced against all politicians since they all appear self-absorbed.)

[circmand]

All a bunch of BS. The planet has had ice ages and Hotter spells ever since the magma cooled. The planet sits on an axis that fluctuates between 23 and 23 and 1/2 degrees. In addition its orbit around the sun fluctuates from closer and neerer affecting the planet temp as well as the sunspots affecting the temp on the sun by thousands of degrees. The deserts we now have at times were on the shore or had lush plant life. Some of the mountains were below the oceans surface and some of the ones below the surface used to be above. Considering that there were also no effective ways of measuring the temp back then the worry of a few degrees is silly and to place the blame on man made activities is non scientific to say the least. If you want you can send all your money to Al Gore and the Soldrinya but quit sending mine.

[VXR]

All a bunch of BS. The planet has had ice ages and Hotter spells ever since the magma cooled. The planet sits on an axis that fluctuates between 23 and 23 and 1/2 degrees. In addition its orbit around the sun fluctuates from closer and neerer affecting the planet temp as well as the sunspots affecting the temp on the sun by thousands of degrees. The deserts we now have at times were on the shore or had lush plant life. Some of the mountains were below the oceans surface and some of the ones below the surface used to be above. Considering that there were also no effective ways of measuring the temp back then the worry of a few degrees is silly and to place the blame on man made activities is non scientific to say the least. If you want you can send all your money to Al Gore and the Soldrinya but quit sending mine.

It is a fact the earth is currently warming. I think it is BS that people on both sides of the issue use it as a political/economic argument. Weather you blame it on nature or man melting polar ice and a rise in ocean levels is a valid concern.

[Ldub]

All a bunch of BS. The planet has had ice ages and Hotter spells ever since the magma cooled. The planet sits on an axis that fluctuates between 23 and 23 and 1/2 degrees. In addition its orbit around the sun fluctuates from closer and neerer affecting the planet temp as well as the sunspots affecting the temp on the sun by thousands of degrees. The deserts we now have at times were on the shore or had lush plant life. Some of the mountains were below the oceans surface and some of the ones below the surface used to be above. Considering that there were also no effective ways of measuring the temp back then the worry of a few degrees is silly and to place the blame on man made activities is non scientific to say the least. If you want you can send all your money to Al Gore and the Soldrinya but quit sending mine.


It is a fact the earth is currently warming. I think it is BS that people on both sides of the issue use it as a political/economic argument. Weather you blame it on nature or man melting polar ice and a rise in ocean levels is a valid concern.

EVERYONE RUN...we're all gonna DIE...

Well...SOME day anyway...:yesgray:

Some of us, sooner than others.

The trick is...be ready, willing, & able to die at a moments notice...dirt:sleepgray

Cuz that's all the notice a lot of us are gonna get.

Sorry JDM, I dunno how it got jak'd to this point, but I cunna resist...:flower:

[VXR]

EVERYONE RUN...we're all gonna DIE...

Good one:rollb:

[Ldub]

Good one

:thanx:

[89Vette]

I think it's pretty naive to think all the carbon waste we put in the environment gets "absorbed" and causes zero damage.

I'm no expert or Al Gore fanatic (since I'm driving a Corvette and VX), but I think trivializing the issue is ignorant -- to say the least.

[Ldub]

I think it's pretty naive to think all the carbon waste we put in the environment gets "absorbed" and causes zero damage.

I'm no expert or Al Gore fanatic (since I'm driving a Corvette and VX), but I think trivializing the issue is ignorant -- to say the least.

Yeh...I'm ignorant as hell...:yesgray:

But on the plus side for me...I've never even wanted to own a vette...not even when I was 11...:_confused...:laughing:

And to be a bit more Burnsian...(Frank)...I have 0 children, I have reproduced 0 times, I have 0 heirs, &...to top that list...

I have 0 cares...what will be, will be...don't believe a word of it, matters not to me, for some day...

worm food... we all shall be...:yes:

[JHarris1385]

It is also a fact that the ozone "holes" are smaller than they were in the 70's.

..

JDM - update us with your results.

[VXR]

I have 0 cares

so all those posts you make about karma are BS:confused:

[Ldub]

so all those posts you make about karma are BS:confused:

Not in the least, I walk the earth doing the right thing as often as my imperfect self is able...

On the other hand...what you see in the mirror...:smilewink

[VXR]

Not in the least, I walk the earth doing the right thing as often as my imperfect self is able...

So as you �walk� the earth perhaps you should consider �walking� this site with the same philosophy:yesb:

[JHarris1385]

Not in the least, I walk the earth doing the right thing as often as my imperfect self is able...


Wow, I like that.

[Ldub]

So as you “walk” the earth perhaps you should consider “walking” this site with the same philosophy:yesb:

It's become very apparent

To me at least

That you like to smack the hive, then step back in wonder & amazement, as you're being stung...:_thinking...http://www.techimo.com/forum/attachments/suggestion-box/14393d1117651123-pokey-stick-smiley-poke.gif...:slap:...:laughing:...:slap:...:laughin g:

[89Vette]

So as you ?walk? the earth perhaps you should consider ?walking? this site with the same philosophy:yesb:

(Sounds like you're expecting too much from "Mr. Turd in the punchbowl". After all...He says he's doing the best he can! LOL)

Though I'm skeptical that the VX is programmed too rich from the factory, I will be interested to see how the OP's modifications work. If it does help, I'll wonder if this mod is compensating for another issue (like O2 or MAF).

I think the bigger issue with going lean is to the converters. They die first. Engines can tolerate leaner than stoich burn ratios as lower loads. At WOT, it's a bad idea.

How is this much different than the IAT trick?

[blacksambo]

I never wanted one either.

[Robbomaz]

The ozone holes being smaller could be due to the reduction in flurocarbons and the like since th 70's. I know us here in WEst Aus can lay claim to one of the bigger holes and some of the worlds highest UV.

I have kids so events of the future are something I think about, but in the end it's my kids that have to deal, and they will. I remember my gearhead Dad telling me during the 70's fuel crisis that I probably wouldnt be able to enjoy 'motoring' (as he quaintly put it) because there would be no fuel any more. Yet we still have fuel, and the air in a lot of cities is vastly better than it was in the past despite exponential population & vehicle growth...

I think there's enough of us doing our thang to make a planetary change happen, and that Global Warming is a fact, but I also believe the Ma Nature has many ways of restoring the balance of things, most of which we ain't even seen yet. And I'm quite sure the redress of the balance wont necessarily be pleasant either. If we were at the start of an Ice Age Global Cooling would be the catch cry OMG OMG!!

Currently I think its a bandwagon for anyone who wants media time, and a vehicle to gather sentimental support for politicians.

Dunno about there boys & girls but here close to 75% of the fuel price is govt tax - and it is levied as a % so the higher the price goes the more they rake in.
But we digress .... How's the device working out?

[Robbomaz]

(Sounds like you're expecting too much from "Mr. Turd in the punchbowl". After all...He says he's doing the best he can! LOL)

Though I'm skeptical that the VX is programmed too rich from the factory, I will be interested to see how the OP's modifications work. If it does help, I'll wonder if this mod is compensating for another issue (like O2 or MAF).

I think the bigger issue with going lean is to the converters. They die first. Engines can tolerate leaner than stoich burn ratios as lower loads. At WOT, it's a bad idea.

How is this much different than the IAT trick?

Speaking for OUR ECU, which is probably programmed a little differently, when you hook up a bank of sensors and watch behavior you can see where the poor fuel consumption is coming from.
At 20% TPS ign was +40 and A/F was 14.2, At 25% the ign was +12 and A/F was 12:1.......ANY kind of load saw these numbers, with the A/F dipping into the mid 11's at WOT. The system stays in closed loop a lot of the time and has knock sensing so the setup is odd to say the least.

So a lot of the time they are rich and retarded, and thirsty :confused:

We are nerdy enough to have got access to the tables in the ECU, but not nerdy enough as to read them & know what they mean.....:mado:

[Robbomaz]

so all those posts you make about karma are BS:confused:
My Karma ran over his Dogma

[89Vette]

Speaking for OUR ECU, which is probably programmed a little differently, when you hook up a bank of sensors and watch behavior you can see where the poor fuel consumption is coming from.
At 20% TPS ign was +40 and A/F was 14.2, At 25% the ign was +12 and A/F was 12:1.......ANY kind of load saw these numbers, with the A/F dipping into the mid 11's at WOT. The system stays in closed loop a lot of the time and has knock sensing so the setup is odd to say the least.

Wow...Are you sure that's "normal" for the fleet of VX units? If so, it shows that the WOT circuit must be set to engage at 25% TPS. That's certainly possible -- as it's a "trick" for tuners to do this to make a performance tune/motor seem snappier. It also shows why the people getting the best MPG drive (and I quote) like a tennis ball is under the gas pedal.

Running in closed loop is normal. That's what all motors (should) do after open-loop warm-up. Closed loop means the O2 sensor is providing feedback to the ECM for correction of the fuel trim data.

14.2 is the correct stoic ratio for ethanol (E10). So, that part would be correct -- unless you were running 100% gasoline.

[Robbomaz]

Wow...Are you sure that's "normal" for the fleet of VX units? If so, it shows that the WOT circuit must be set to engage at 25% TPS. That's certainly possible -- as it's a "trick" for tuners to do this to make a performance tune/motor seem snappier. It also shows why the people getting the best MPG drive (and I quote) like a tennis ball is under the gas pedal.

Running in closed loop is normal. That's what all motors (should) do after open-loop warm-up. Closed loop means the O2 sensor is providing feedback to the ECM for correction of the fuel trim data.

14.2 is the correct stoic ratio for ethanol (E10). So, that part would be correct -- unless you were running 100% gasoline.
Not a VX - hence 'our' ECU - Jackaroos. Four 3.5 manuals behave the same way.
Well aware of it as a tuner trick - have done it - but not usually seen on OEM setups. Pretty much ditches everything from 25% TPS upwards. :(
With O� and knock sensors it could be much leaner & more advanced a lot of the time
The supercharged units are returning much better fuel economy than the stockers despite being driven with somewhat more *cough* enthusiasm :yeso:

[VXR]

you like to smack the hive, then step back in wonder & amazement, as you're being stung

Smack the hive:rollb:

Being stung:laughb:

You sir are delusional:yesb:

[Ldub]

Smack the hive:rollb:

Being stung:laughb:

You sir are delusional:yesb:

They've got this new thing, it's called a metaphor (http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CEcQFjAB&url=http%3A%2F%2Fdictionary.reference.com%2Fbrowse %2Fmetaphor&ei=O6d5T7m0CsiXgweXw-CIDw&usg=AFQjCNEL8oO-9dqnDoSmiu0V89JVbdwSww&sig2=frRKwHhsvgrMkViVbgh8NQ)...:smilewink

[Robbomaz]

What does a bullfighter have to do with this?

[89Vette]

Matador....:dan_ban: Good one! But, it's more like a bunch of bull....

Who's humor is like junior high school :badhorse:


Not a VX - hence 'our' ECU - Jackaroos. Four 3.5 manuals behave the same way.

Does this mean other Isuzu's are set up the same way? Is Jackaroos your slang for ECU hacks?


Well aware of it as a tuner trick - have done it - but not usually seen on OEM setups. Pretty much ditches everything from 25% TPS upwards. :(

In terms of MPG, yes. But, you've still got increasing throttle openings and variable power.


With O? and knock sensors it could be much leaner & more advanced a lot of the time

And, that's what you hope to accomplish....right?

[Ldub]

Is Jackaroos your slang for ECU hacks?



Jackaroo is what they call the Troop? in Oz...I think...:_thinking

[Robbomaz]

Jackaroo is what they call the Troop? in Oz...I think...:_thinking
Not quite. Put correctly, Jackaroo is what you lot erroneously call the Trooper :smilewink

And I see you fixed your spelin...

[Robbomaz]

Matador....:dan_ban: Good one! But, it's more like a bunch of bull....

Who's humor is like junior high school :badhorse:

Growing up is overated




Does this mean other Isuzu's are set up the same way? Is Jackaroos your slang for ECU hacks?

Its actually the guys that round up livestock here, and the proper name for your Trooper. The girls are Jillaroos. I cant comment on the other Isuzus, cos we havent put anything but Jacks on the dyno, but given the uniformly woeful fuel consumption, probably. Seems silly to me that I can get more power, torque AND economy from an LS2.....



And, that's what you hope to accomplish....right?
Not me, JDM. Although I wouldnt mind. Nor anyone else with one of this engines I'm sure. My response was in regard to your comment regarding running rich OEM - here in OZ, they do, at least on our four Jackatroopers

We have a Rodeo ECU (Rodeo here is a pickup, not a wagon) that we are going to try. Rodeo 3.5s dont have knock sensing, EGR or variable intake runners but they do have the highest quoted factory torque/power of all the 6VE1's sold here so weez thinking maybe the Hitachi ECU has better mapping than the Delphi, plus its a completely sealed unit.

[Ldub]

And I see you fixed your spelin...

Oy...good eye...:thumbup::thumbup:

[89Vette]

Growing up is overated

FWIW, my comment wasn't directed to you...



Seems silly to me that I can get more power, torque AND economy from an LS2.....

true, but it's probably in a lighter vehicle, has 2wd, and possibly a 6-spd.


Not me, JDM. Although I wouldnt mind. Nor anyone else with one of this engines I'm sure. My response was in regard to your comment regarding running rich OEM - here in OZ, they do, at least on our four Jackatroopers

Jacka-what? :bwgy: Sorry, I forgot you weren't the OP.


We have a Rodeo ECU (Rodeo here is a pickup, not a wagon) that we are going to try. Rodeo 3.5s dont have knock sensing, EGR or variable intake runners but they do have the highest quoted factory torque/power of all the 6VE1's sold here so weez thinking maybe the Hitachi ECU has better mapping than the Delphi, plus its a completely sealed unit.

great idea!:thumbup:

[VXR]

What does a bullfighter have to do with this?

no he said M-E-T-A-P-H-O-R:laughb:

I am not sure what that is but it sounds funny:rotate:

[Robbomaz]

no he said M-E-T-A-P-H-O-R:laughb:

I am not sure what that is but it sounds funny:rotate:

I saw you with the Tax Collection lady. We're you paying your taxes?
Yep. That's what I metephor

[89Vette]

Soooo.....That's what he met-her-for!!!

:bwgy::smilewink:bgwo::bgwb:

[89Vette]

We have a Rodeo ECU (Rodeo here is a pickup, not a wagon) that we are going to try. Rodeo 3.5s dont have knock sensing, EGR or variable intake runners but they do have the highest quoted factory torque/power of all the 6VE1's sold here so weez thinking maybe the Hitachi ECU has better mapping than the Delphi, plus its a completely sealed unit.

BTW...Are you certain the cam's are the same? Even within SBC's their can be cam differences which would account for rating's differences.

I'd be surprised if Isuzu left any timing on the table. OTOH, raising PE from 25% to 50-60% could be worth 1-2mpgs.

I'd bet a good 2wd/4wd switching system (or even gear box) would make as much or more difference. (maybe combine the two?) FWIW, any Jeep I've ever seen rated (and/or owned) did much better in 2WD vs 4WD mode. I could feel a difference in power as well. Just seems to be way less drivetrain loss.

Look at the difference in the 2wd vs 4wd Ford Escape's MPGs. Fairly significant in my book. (I wonder if there's any other changes in gearing, etc between these.)

[Robbomaz]

BTW...Are you certain the cam's are the same? Even within SBC's their can be cam differences which would account for rating's differences.

I'd be surprised if Isuzu left any timing on the table. OTOH, raising PE from 25% to 50-60% could be worth 1-2mpgs.
Agree. For our job#1 truck to go from 3.2 SOHC N/A to 3.5 DOHC supercharged, gain a rooftop tent windsock and STILL return nearly 3 litres/100 better economy says that the 'power under the curve' of the SC is a major factor.
Cams here are very mild. I have heard that the cams in the Axiom are better, but only hearsay nothing conclusive. We never got Axioms here anyway


I'd be a good 2wd/4wd switching system (or even gear box) would make as much or more difference. (maybe combine the two?) FWIW, any Jeep I've ever seen rated (and/or owned) did much better in 2WD vs 4WD mode. I could feel a difference in power as well. Just seems to be way less drivetrain loss.

Look at the difference in the 2wd vs 4wd Ford Escape's MPGs. Fairly significant in my book. (I wonder if there's any other changes in gearing, etc between these.)

None of ours are TOD, so are always 2WD unless selected. For fuel range calcs off-road I always use 25l/100 (10 mpg) - long way between fuel pumps in Outback Australia!

[89Vette]

I forgot to mention that knock sensors were employed largely to allow for more aggressive timing. By installing them, you give the ECU a means to monitor and back out timing when fuel is insufficient to run w/o knock (pinging). Moreover, you allow for a more aggressive timing curve since the knock sensors provide that safety net. It seems hard to believe an ECM w/o knock sensors is more aggressive than a system with them!

You sound like you'd know that.

That's why I have to wonder why cam, gearing, exhaust or some other physical configuration would account for the difference in dyno numbers.

[VXR]

EVERYONE RUN...we're all gonna DIE...

I think we may be OK

[Robbomaz]

I forgot to mention that knock sensors were employed largely to allow for more aggressive timing. By installing them, you give the ECU a means to monitor and back out timing when fuel is insufficient to run w/o knock (pinging). Moreover, you allow for a more aggressive timing curve since the knock sensors provide that safety net. It seems hard to believe an ECM w/o knock sensors is more aggressive than a system with them!

You sound like you'd know that.

That's why I have to wonder why cam, gearing, exhaust or some other physical configuration would account for the difference in dyno numbers.
Most of the late model knock-sensed cars we have had on our dyno run right on the knock threshold stock - we have a gadget that lets the operator listen to the knock sensor in headphones during a run - there is a lot of activity from the sensor and micro adjustments going on all the time. Tapping a bolt on the head lightly with a hammer sees the advance drop and return almost instantly.

The only conclusion we can make is that the knock sensor in our Jacks is not so it can run on the raggedy edge of detonation (the ign adv behavior proves that) it is so it can 'see' crap fuel.
Rodeo is considered a tradesmans ute and would spend its life in metropolitan areas and Jackaroos are intended to go into BFN - the Rodeo lives where good fuel is the norm and the Jack could be somewhere where there is only crappy fuel. Your VX's may be programmed similarly to our Rodeos, using the knock sensor in the more 'normal' way
Recovery of a broken-down 4WD costing upwards of $10K are not unheard of here - it is possible to get a looooooooooooooong way from anything at all :yesy:

[89Vette]

I'm not sure I follow. Tapping should cause retard. Without continuous knocking, it also should recover almost instantly.

What you described sounds like normal KS behavior. How are you concluding there's more room for advance (vs it already having timing table with "max" timing)?

Is their any way (with a coil pack, distributor-less system) to mechanically advance global electronic timing a couple of degrees?

[Robbomaz]

Tapping does cause retard - I said advance drops, which I can see is confusing. My bad.
At around 22% TPS it is using 38° advance and there is mild activity on the knock sensor. 3% more TPS and ign is at 16° with no activity on the KS. That clearly aint max timing for that load....!

The CAS chopper wheel is on the crank inside the crankcase, and the pickup bolts into the block with no adjustment

[89Vette]

38-deg advance sounds about right for light load conditions and medium rpms. I'm sure you know (as I) that TPS position doesn't necessarily correspond to load conditions. Going up a hill with 25% throttle requires difference mapping than 25% throttle downhill.

Assuming the physical load on the motor didn't change drasticcally, I agree that a drop from 38 to 16 degrees (with only 3% more TPS increase) is perplexing. The only place my SBC has advance that low is in the lowest rpms for maximum load (to avoid knocking during anything resembling engine lugging.)

In a quick search thru this forum, I didn't find anyone knowing of a successful ECU reprogram. Do you know any way to hack into the fueling and/or timing tables? What tool(s) do you use to monitor the conditions you're seeing.


BTW...Interesting that you say "My bad" in Oz.

[Robbomaz]

38-deg advance sounds about right for light load conditions and medium rpms. I'm sure you know (as I) that TPS position doesn't necessarily correspond to load conditions. Going up a hill with 25% throttle requires difference mapping than 25% throttle downhill.

Assuming the physical load on the motor didn't change drasticcally, I agree that a drop from 38 to 16 degrees (with only 3% more TPS increase) is perplexing. The only place my SBC has advance that low is in the lowest rpms for maximum load (to avoid knocking during anything resembling engine lugging.)

In a quick search thru this forum, I didn't find anyone knowing of a successful ECU reprogram. Do you know any way to hack into the fueling and/or timing tables? What tool(s) do you use to monitor the conditions you're seeing.


BTW...Interesting that you say "My bad" in Oz.
We have got as far as seeing the code. We dont know what we are looking at or what it means :( Need to find a Supernerd who can take the time to dig thru it. Its a Delphi but we no speekee its lingo. As a side chore we are looking for which programmable GM ECU can interface. Ign is the sticking point - the one on the Gen IV Chev V8 comes closest so far in that the crank chopper is the same, but cam position signal isnt :(

We have a GM Tech 2 and a bunch of other OBD tools, + the dyno can display a lot of info in real time, not to mention the 'closed road testing with professional drivers under controlled conditions' that we *cough* dont do.....:winkb:

[89Vette]

One of the reasons I ask relates to my knowledge of my vette programming. It's got (had) some weird stuff. And, the thing I didn't like the most was how the timing tables were set up.

In 89, GM used a primary timing table with columns for load and rows for RPMs. It also used secondary tables for PE (power enrichment). In the secondary tables, additional timing and fuel were added (summed) to the primary tables (creating a final total of fuel/timing for extra zippy-do-da-day.) Oddly, I found errors in the tables...or at least the ones claiming to be stock tables as stored on programmers websites (like Moates/Tunerpro).

To confirm the stock tables on tuner websites appeared accurate, I burned a chip with one...made the minimal changes for my 383 (FI size, min rpm, etc) and installed that chip. I observed very similar behavior to stock.

I could post pics of tables if you thought it might be relevant, but in the higher load columns, primary timing dropped -- fairly significantly. That's where the PE values were added back in...putting total timing back in the same ball-park as the lower load columns. (Keep in mind higher loads still have less total timing than lower rows but the table would not look linear w/o seeing the PE adders.)

There were also a stray cell here and there that was unexplainable. One were timing was 5-10 degrees lower than values in all adjacent cells. It made me wonder if timing tables were created using a mildly faulted algorith, if GM engineers were drunks, or if the tuner sites recreated tables while on drugs. In either case, I corrected the handful of timing table cell errors to observed driving performance. It was a bit smoother/better.

Finally, I removed all PE values (common practice in DIY tuner circles) and made my primary timing table show the summed timnig curves. This resulted in significantly smoother transitions since PE didn't pop in here'there. IOW, I no longer could feel the transitions while driving the car -- which was good.

If GM and Isuzu shared any timing technology, maybe the later ODB2 systems use similar techniques in their timing formulas. If so (and depending on how you're seeing your timing values), it could explain the sudden drop in timing. Since 25% TPS is where you see fuel PE, maybe that's also where timing PE kicks in. And, if the PE table has a starting value of something like 10-degrees, you may need to add it to the 16-deg in the base table -- for a summed value of 26-deg total timing.

Just a guess here, but it's the only thing I can think of after seeing (and recoding) my older GM ODB1 system.

[Robbomaz]

Its quite possible thats what is going on. All we get is a screen full of ascii at this point. Hence the need for an intrigued supernerd! We cant see anything intelligible - yet.

Most of the Isuzu sensors seem identical to the across the board GM stuff. The Gen IV V8 ECU is crackable/programmable, has a crank angle wheel identical to the Isuzu, but has 4 cam position triggers to the Isuzus one. Thinking of setting up an external drive that will take the V8 cam position wheel and just seeing if we can get it going - but the time for that has to fit in around customers....!
I have seen the 'rogue setting in one box' on GM ECUs too - it does make you wonder.

[Robbomaz]

Bit more homework last nite. Gen 3 V8's have the right cam signal input, but the wrong crank angle wheel. Gen 4's have the right crank angle wheel but the wrong cam signal....!
No doubt all this - like the number of O2 sensors to be read - can be turned on and off in software once access is gained
I can send you the .bin file from the Isuzu ecu if your interested

[89Vette]

Bit more homework last nite. Gen 3 V8's have the right cam signal input, but the wrong crank angle wheel. Gen 4's have the right crank angle wheel but the wrong cam signal....!
No doubt all this - like the number of O2 sensors to be read - can be turned on and off in software once access is gained
I can send you the .bin file from the Isuzu ecu if your interested

I'd probably need a TunerPro mask to make any sense of it.