Worth upgrading my ECM??

[Rob 689]

I have a 94 k1500 5.7 manual with i beleive an untuned cam swap as is when i bought it. I think this due to BLM being at 99~101 at idle fully warmed up and in closed loop, and 135~137 at around 4,500-5,000 rpm. Slightly rough idle and real stinky rich smell with a random miss like hickup but not quite a miss every couple seconds and inconsistently. I soldered in the adapter to run the flash sf512 chip instead of the factory prom and have disabled and blocked off the egr system by setting the minimum on temp to 150c in tunerpro and also the speed minimum to 255 MPH. I took out a bit of fuel from idle on up to about 2200 and eventually 2400 rpm and up to about 30 kpa on the map and the idle cleaned up a ton. its rough sometimes and spot on others i think i tuned while another table was active i am learning and need to do it again its still not done and slightly like surgy through the power curve but overall its not terrible its definitaley driveable but horable gas mileage too. I do have edelbrock headers on the truck that came off another 94 and a full 2 inch y into 3 inch straigt pipe all the way back past the axle. All the sensors are working properly and i just rebuilt the throttle body and re used the injectors but throughly bench cleaned them under pressure and with tapping the voltage to spray off on a bunch. Great spray pattern and zero leaks. Brand new quality o2 sensor. No vacuum leaks. Brand new fuel pump, filter, and regulator. just barely broke 200,000 miles on the odometer. overall truck is in great condition. new plugs wires cap rotor etc. No cat and no muffler. my o2 sensor is a single wire btw, will be upgrading to a 3 wire soon tho.

The truck has the 16196396 ECM with BDUY BCC and .bin

I have out of a suburban with an E tranny a PCM with red and blue connectors, 16196395. It has a calpac and everything with the internal knock control system.

I have the motor from that truck in my garage getting built too with vortec heads etc.
would it be worth it at all to upgrade to that other PCM?

Is that other one even better or does it just also control an auto trans?? what do the red and blue connectors mean? arent those the desirable ECMs?

My truck currently has the external ESC system tied in with the knock sensor, would i have to change that or is just repinning the harness good enough?

I do have the entire harness out of the suburban as well so if i needed to chop or change the harnesss i could just swap it with the one that came with the PCM

Eventually i would like to go to a port injected or the TPI spider injection or some sort of 8 cylinder injection instead of the TBI. or else ill just rock a 454 tbi if its too expensive i do have budget in mind. I also think i want to do a mild turbo some time in the LONG distant future.

[Rob 689]

P.S.

I am using the $9A mask and before i screwed with any of the fuel map the only time the BLM returned 128 was WOT around 3,000 or 3,500 ish rpm. I do also have before and after data logs and copys of my bin alterations if anybody is interested in taking a peek.

Oh and i almost forgot im using histogram blm averages too btw. the generel trend that i am seeing with my inexperienced eyes is decenlty low down low and good in the middle and lean up top, i think im on the right track but not quite certain just yet.

Oh and the truck still has its TBI heads as far as i can tell.

[stew86MCSS396]

When you enter PE mode (WOT), BLM/INT lock at 128 and fuel is added accordingly based on parameters set in PE AFR parameters. You really need to dial in all of VE to return BLMs ~128.

[Rob 689]

What table or parameters need to be disable before adjusting VE tables?

I know i need to build a proper fuel map. got called out of town for work mid progress on the tuning. Im also still learning and just barely got going with burning chips and im starting to understand whats going on and what im targeting with my changes and what not but i am still very new and inexperienced and i am learning everyday.

Ive been reading a few things about these auto tuning spread sheets? you load BLM histogram data and fuel map data and it gives you new corrected fuel map?? sounds too good to be true? worth it?

[Rob 689]

When you enter PE mode (WOT), BLM/INT lock at 128 and fuel is added accordingly based on parameters set in PE AFR parameters. You really need to dial in all of VE to return BLMs ~128.

Also thank you i didnt know that. Is there some where i can read on the operation of the ecm and how the tables interact and when the different circuits come on and off line? like description and operation basically??

[dave w]

The second generation TBI PCM's: 16197427, 16156930, 16196395, and 16168625 have excellent aftermarket support. These PCM's have "Hacks" to run 8 high impedance injectors (like TPI / Vortec 5.7 / Vortec 7.4 Injectors) and control Electric Radiator Fans.

The 16196395 was used with some 7.4 / Manual Transmission vehicle applications. http://www.gearhead-efi.com/Fuel-Inj...Information-OE

The 16196395 chip requires custom programming for 5.7 / Manual Transmission.

I recommend upgrading to a Second Generation TBI PCM, but the "Learning Curve" can be steep. Wiring and soldering skills are often required with a PCM conversion.

dave w

[Rob 689]

The second generation TBI PCM's: 16197427, 16156930, 16196395, and 16168625 have excellent aftermarket support. These PCM's have "Hacks" to run 8 high impedance injectors (like TPI / Vortec 5.7 / Vortec 7.4 Injectors) and control Electric Radiator Fans.

The 16196395 was used with some 7.4 / Manual Transmission vehicle applications. http://www.gearhead-efi.com/Fuel-Inj...Information-OE

The 16196395 chip requires custom programming for 5.7 / Manual Transmission.

I recommend upgrading to a Second Generation TBI PCM, but the "Learning Curve" can be steep. Wiring and soldering skills are often required with a PCM conversion.

dave w

Awsome great info to head I deffinatly want to run electric fans at some point and hacking to run 8 injectors sounds like exactly what I need.

im not worried about the learning curve as I am an avid and quick learner. I have nearly 2 years of training in the GM ASEP technician training program at my local university. Unfortunately poor life decisions led to me not finishing a few of the last couple classes.

I have three semesters worth of advanced automotive gm specific electrical training and wire diagrams are as easy as reading a sentence for me. I have been soldering on game consoles broken surround sounds and anything else I could get my hands on etc since I was about ten or 11 years old. Often with crap iron crap solder no flux etc. learn how to not burn pads with an old burnt Walmart soldering iron and the fat crap solder and a mod chip in an xbox lol.

I also am already up and running on a modified bin with a 27sf512 28 pin flash chip and a soldered in moates G2 memory adapter.

i need help learning more specifics about the software side of the ecm and how to properly get it dialed in and ya know just a little bit of guidance with my build.

another question,, should I spend the money on a wide band o2 and run it on the egr input to the pcm?? I’ve heard of that but don’t know how. Or should I wait till I have more mechanical mods on my build like do I need that with N/A and mild upgrades?

[stew86MCSS396]

Do you have an xdf and adx for your ECM? I wouldn't be opposed to learning on it but if it puts data out at 160 baud, you're going to appreciate going to the faster red/blue connector PCM.

[Rob 689]

Do you have an xdf and adx for your ECM? I wouldn't be opposed to learning on it but if it puts data out at 160 baud, you're going to appreciate going to the faster red/blue connector PCM.

Yes I do have those files for my 6396 ecm and I can get them for the 6395 ecm from here on gear head there’s loads for that one on here

and yeah my current one the 6396 ecm is 160 baud which I’m told is yuck but I didn’t know why lol I was wondering why the data stream was slow af and crap lol

so I’ll definitely be upgrading as soon as I get back home from working. I’ll upgrade immediately and just tune on that one and skip the waste of time working with my current ecm? Or would it be a good idea to get proficient while it at least still runs? I do daily the truck. Once I put the other one in with now proper bin to run my motor trans combo I would probably benefit from some previous experience at that point right?

when I do finally upgrade would I just take the 7.4L manual tans bin and copy and paste my current tune in then polish it up and fill the higher resolution in?? Or something like that?

anything special with the upgrade besides the harness reworking?
I do have the harness that came with the 6396 pcm and would it be easier to re pin the one in the truck and chop out the external esc module and re wire the knock sensor or just take the other harness open the loom and remove the auto tabby portion?

I do have the knock sensor that matches my new pcm too are they different?

[Rob 689]

Do you have an xdf and adx for your ECM? I wouldn't be opposed to learning on it but if it puts data out at 160 baud, you're going to appreciate going to the faster red/blue connector PCM.

Here are the files for the ecm if interested, i was only on my phone earlier i finally got to my laptop lol.

[Rob 689]

Yes I do have those files for my 6396 ecm and I can get them for the 6395 ecm from here on gear head there’s loads for that one on here

and yeah my current one the 6396 ecm is 160 baud which I’m told is yuck but I didn’t know why lol I was wondering why the data stream was slow af and crap lol

so I’ll definitely be upgrading as soon as I get back home from working. I’ll upgrade immediately and just tune on that one and skip the waste of time working with my current ecm? Or would it be a good idea to get proficient while it at least still runs? I do daily the truck. Once I put the other one in with now proper bin to run my motor trans combo I would probably benefit from some previous experience at that point right?

when I do finally upgrade would I just take the 7.4L manual tans bin and copy and paste my current tune in then polish it up and fill the higher resolution in?? Or something like that?

anything special with the upgrade besides the harness reworking?
I do have the harness that came with the 6396 pcm and would it be easier to re pin the one in the truck and chop out the external esc module and re wire the knock sensor or just take the other harness open the loom and remove the auto tabby portion?

I do have the knock sensor that matches my new pcm too are they different?

EDIT, i listed those ecms backwards. got confused with the partnembers. I have the harness that matches the new computer that i will be upgrading to

[dave w]

WBO2 information here: http://www.gearhead-efi.com/Fuel-Inj...ng-Spreadsheet

[Rob 689]

WBO2 information here: http://www.gearhead-efi.com/Fuel-Inj...ng-Spreadsheet

How critical is the wbo2? I know it sounds like I’m a cheap ass and I kinda am but Isn’t the narrow band o2 good enough as long as your within it’s range. I know upgrading to a heated sensor has its benefits

also your spread sheet file is titled for the 7427 ecm? As long as I’m in the right xdf for the same mask and it’ll still work on mine right?

[steveo]

you'll never get your power enrichment fueling right on without a wideband.

a narrowband is going to read at maximum voltage between like 0:1 and 14:1 AFR. so if you are at like 14:1 it'll be 900+mv. or if you're at 8:1 it'll be 900+mv.

lets say your engine makes maximum power around 13:1 AFR, how would you attain that?

there is zero good data from a narrowband that will help you tune open loop or power enrichment ranges, which is where you tune for power.

from a tuning perspective you can think of a narrowband like a switch. it effectively says 'richer than stoich' or 'leaner than stoich'. that's pretty much all.

you can kinda get there without a wideband by disabling power enrichment and forcing closed loop everywhere, then driving the hell out of it in ranges which are not very safe without that extra fuel, but to get data. once that is done and your base VE tables are correct across the board, you can add your power enrichment fuel and maybe be in the ballpark, but in that case you want to tune a bit on the rich side in case you're wrong.

if you do not want to buy a wideband or use the hacky closed loop method, you could buy a few pulls on a dyno (which has a tailpipe wideband) and simply use that data to map your wide open throttle AFR target

[Rob 689]

you'll never get your power enrichment fueling right on without a wideband.


a narrowband is going to read at maximum voltage between like 0:1 and 14:1 AFR. so if you are at like 14:1 it'll be 900+mv. or if you're at 8:1 it'll be 900+mv.


lets say your engine makes maximum power around 13:1 AFR, how would you attain that?


there is zero good data from a narrowband that will help you tune open loop or power enrichment ranges, which is where you tune for power.


from a tuning perspective you can think of a narrowband like a switch. it effectively says 'richer than stoich' or 'leaner than stoich'. that's pretty much all.


you can kinda get there without a wideband by disabling power enrichment and forcing closed loop everywhere, then driving the hell out of it in ranges which are not very safe without that extra fuel, but to get data. once that is done and your base VE tables are correct across the board, you can add your power enrichment fuel and maybe be in the ballpark, but in that case you want to tune a bit on the rich side in case you're wrong.


if you do not want to buy a wideband or use the hacky closed loop method, you could buy a few pulls on a dyno (which has a tailpipe wideband) and simply use that data to map your wide open throttle AFR target

Ahh I see makes sense. I knew they weren’t as accurate and in a very short range didn’t realize it was like that tho. Is it possible to replace the regular o2 with a wide band and run the engine on that? Like get ride of the narrow all together so I still only have one? I do have proficient welding skills and could totally weld a bung in my exhaust wherever needed but just considering my options. Also thank you for the reply