1994 LT1 calibration 16230221 couple questions

[babywag]

So in Feb. I bought a '94 Caprice wagon. On TIS website it listed 16230221 as latest calibration.
I grabbed it from EEHack site, and reflashed my pcm with it.

Couple things I noticed one before reflash, and one just now.

The MAF was disabled in this calibration, why? (I enabled it before I reflashed, but curious).

I was just looking through the .bin, and comparing it to others, and noticed something I think is odd.
The o2 swing voltages are different left/right, in both calibrations. Also looked @ a couple others (b-body), and they are also different.
For giggles I loaded an f-body .bin, and the swing voltages are the same left/right, so it's not a definition file error??

Why would they be different, I don't think I have ever seen that before.

[steveo]

the differences in swing voltage is present in the y-body bins too. my best guess is the harness has a bit more resistance on one side than the other, since it's only a few mv.

however if the maf is disabled, it's possible the 16230221 calibration is mislabeled on my site?

[babywag]

the differences in swing voltage is present in the y-body bins too. my best guess is the harness has a bit more resistance on one side than the other, since it's only a few mv.

however if the maf is disabled, it's possible the 16230221 calibration is mislabeled on my site?

Maybe I should just go back to original calibration then?

Also noted couple differences with latest version of EEHack.
Connection now errors out on initial connect (never used to).
ABS light comes on while connected (also never used to).
Neither is a big deal to me, and doesn't seem to effect anything.

I changed the swing voltages to equal each other, and the blm's are more balanced now vs. before.
Haven't compared the logs closely yet, but just from initial look, I remember they had a greater split between them before.

[steveo]

you mean it actually worked before the latest version on your caprice!?

try unchecking 'silence extra modules'

if that fails use f-body mode

please report back with results, b-bodies are not very well tested with eehack at all.

[steveo]

I changed the swing voltages to equal each other, and the blm's are more balanced now vs. before.
Haven't compared the logs closely yet, but just from initial look, I remember they had a greater split between them before.

eehack > analyzer > o2 sensor voltage analysis

check peak/low/average. personally i tune by 'peak' and set the swing voltage difference between the two banks as the difference here. it's given good results where you need to compensate for resistance differences in harness/connections/etc.

[babywag]

you mean it actually worked before the latest version on your caprice!?

try unchecking 'silence extra modules'

if that fails use f-body mode

please report back with results, b-bodies are not very well tested with eehack at all.

Yep, it worked fine before connected immediately no errors etc.
The guy I bought it from was amazed. Said even his buddy with thousands of $$ in test equipment/scanners etc. couldn't tell him what the codes were. LOL
It allowed me to see what was happening during the test drive and negotiate a fair price IMHO.
Had I not found it before the purchase I may not have ever bought the car?


eehack > analyzer > o2 sensor voltage analysis

check peak/low/average. personally i tune by 'peak' and set the swing voltage difference between the two banks as the difference here. it's given good results where you need to compensate for resistance differences in harness/connections/etc.

I switched back to other calibration, I'll reset the o2(s) and I'll give that a try. Newer isn't always better. Especially if it isn't actually the stock calibration listed? IIRC the calibration ID was correct in the .bin? I'd have to double check though.

[Dirtybob]

...

please report back with results, b-bodies are not very well tested with eehack at all.

on my '95 roadmaster I will see 1-3 errors before eehack will connect but no other issues thus far. I've only flashed the pcm 4 times up to this point, apologies for the hijack - dunno if this deserves it's own thread....

[babywag]

on my '95 roadmaster I will see 1-3 errors before eehack will connect but no other issues thus far. I've only flashed the pcm 4 times up to this point, apologies for the hijack - dunno if this deserves it's own thread....

I think the roadmasters/fleetwoods have more chatter than my caprice does on the ALDL line.
Like I mentioned it doesn't really affect anything, just takes a few more seconds to connect.
Some people seem to have problems and need to remove fuses to silence the chatter.
I never did have an issue, it just worked, but it's GOOD that we're being included, it's an awesome program and extremely useful.

[steveo]

Like I mentioned it doesn't really affect anything, just takes a few more seconds to connect.

oh ok, that must be the new connection code. it was more designed for y-bodies.

as long as it connects within a few tries i'm ok with it; but is there any way you could make me a few debug logs with 'verbose' enabled when you try to connect?

maybe i can tune it up a bit.

[babywag]

oh ok, that must be the new connection code. it was more designed for y-bodies.

as long as it connects within a few tries i'm ok with it; but is there any way you could make me a few debug logs with 'verbose' enabled when you try to connect?

maybe i can tune it up a bit.

Sure...I need to adjust the MAF table some, and need more data, so shouldn't be a problem.
Thing is pig rich @ idle and low speed...guessing it's a side effect of removing the home base setup?

[Dirtybob]

... it doesn't really affect anything, just takes a few more seconds to connect.
.... it's an awesome program and extremely useful.

Yes and yes.
I will try to get a few logs too, just need to get the car back from having 3.42s and posi installed first....

[steveo]

guessing it's a side effect of removing the home base setup?

changing the total air volume after the maf (deleting silencers, etc) has a measurable effect on low RPM airflow readings. the mass of air can act as a bit of a pulsation damper to remove the reversion effect that kur4o was talking about earlier. so even though the rate of incoming air doesn't change, the rate of oscillation does.

and on the incoming side, anything that changes the amount of turbulence can dramatically change low to midrange airflow. so changing the air filter doesn't really do much, but smoothing out the intake plumbing does. this can affect low to midrange airflows.

this change usually only adds up to 5% or so, at least when i put the stock plumbing back on my car that's what i observed.

add that to your cam reversion, though....

with a mid-sized cam and performance intake stuff.. cold air intake, better elbow with no silencer etc, i end up to pulling anywhere from 15-25% from a stock maf table below 25-30afgs, then smooth 'er back out towards higher airflows

keep in mind that with a cam, the maf and o2 sensors lie a lot at extremely low airflows (like idle) so be careful not to use your idle data to extrapolate your low end maf table curvature, or your off-idle transition can go south. you can graph your maf with increased logging sample rate and see the mess that happens at low rpm with a maf.

[babywag]

changing the total air volume after the maf (deleting silencers, etc) has a measurable effect on low RPM airflow readings. the mass of air can act as a bit of a pulsation damper to remove the reversion effect that kur4o was talking about earlier. so even though the rate of incoming air doesn't change, the rate of oscillation does.

and on the incoming side, anything that changes the amount of turbulence can dramatically change low to midrange airflow. so changing the air filter doesn't really do much, but smoothing out the intake plumbing does. this can affect low to midrange airflows.

this change usually only adds up to 5% or so, at least when i put the stock plumbing back on my car that's what i observed.

add that to your cam reversion, though....

with a mid-sized cam and performance intake stuff.. cold air intake, better elbow with no silencer etc, i end up to pulling anywhere from 15-25% from a stock maf table below 25-30afgs, then smooth 'er back out towards higher airflows

keep in mind that with a cam, the maf and o2 sensors lie a lot at extremely low airflows (like idle) so be careful not to use your idle data to extrapolate your low end maf table curvature, or your off-idle transition can go south. you can graph your maf with increased logging sample rate and see the mess that happens at low rpm with a maf.


The stock air intake was partially removed when I bought the car.
Home base/plate whatever it's called, and a beefy tube in it's place.
Air filter housing is still stock, new filter & cleaned MAF = no change.
I have replaced a ton of parts on this thing, mostly due to poor previous "repairs", and maintenance needs/things I found wrong.
@ any rate, it ran surprisingly well given the things I found.
Like the optispark filled with oil and bad bearing, the mis-routed & melted plug wires, etc.

Today I removed ~5-10% from idle on up ~midway into 2nd MAF table.
Based on the logs/analysis of the run I took it on last night, it should be good to go now?
Gave it a very good workout, bouncing it off the stupidly low set rev limiter of 4800 in any gear but 1st??
We'll see how it runs/what logs show now, need to drive my daughter to a cross country meet after school so I'll get some good data again?
A short drive running some errands shows it's in the ballpark now vs. the BLM's in the 11x range.

I also emailed you an EEHack connection log, if you need/want anything else just let me know.

[steveo]

best thing to do is load a whole crapload of logs at the same time (from running the same bin) in as many operating conditions as possible, then run the analyzer with its default settings. the resulting maf corrections should be really good. (and so will clusters of knock counts, etc)

using averaging over large sets of data is a great way to nail your fueling map quickly

[babywag]

Yep...here's after.

11008

Here is before.

11009

[steveo]

awesome, looking good!

[babywag]

awesome, looking good!

Thanks, very happy with how it's running now vs. when I bought it.
I'm very surprised that w/ 140k and the original catalytic converters that it even passed smog!
Especially since @ the rpm they dyno test @ is fairly low, 1372RPM in the case of my test.
Even running pig rich (IMHO) w/ BLM's in the 11x range, I'd venture a guess that testing it now would show a marked improvement in test result numbers?

[steveo]

in round figures, a blm of 110 means about ~15% fuel had to be removed to correct the rich condition. not a huge deal, but it does mean before the trims kick in, you were running 'bout ~12.5:1 instead of 14.7:1

[babywag]

in round figures, a blm of 110 means about ~15% fuel had to be removed to correct the rich condition. not a huge deal, but it does mean before the trims kick in, you were running 'bout ~12.5:1 instead of 14.7:1

Technically it shouldn't be running "rich" if everything is working correctly. But it sure seemed/felt like it.
I know low BLMs don't necessarily mean rich, just indicate it's pulling fuel.
Keep having to remind myself though.
Testing numbers seemd high to me, but @ least it passed.

[steveo]

just because trims fix cruising fuel doesn't mean all transitional fuel (most of which isn't really tuneable in $EE) is also trimmed... so until your trims are in line, it's normal for it to run like a bag of shit.

also in every bin i've seen power enrichment by default (and obviously when using a blm locker) only uses trims higher than 128 as a base. so it'll help compensate for lean conditions a bit, but happily dump a ton of fuel if trims are under 128...

[Rocko350]

steve-o,

I never had issued with connection to b bodies or d bodies until the latest update. Flashing, reading, all of it was great. I will try what was suggested.

OP the reason the o2 swing voltages are different is the distance the cat is from the manifolds on the b bodies. Not the differences on where the manifold discharges the exahaust to the cat, and also the firing order of the engine was another reason. There are differences in the 94/95 cars to the 96 cars too. In general I set them all to 450mv.
Chris.

[babywag]

just because trims fix cruising fuel doesn't mean all transitional fuel (most of which isn't really tuneable in $EE) is also trimmed... so until your trims are in line, it's normal for it to run like a bag of shit.

also in every bin i've seen power enrichment by default (and obviously when using a blm locker) only uses trims higher than 128 as a base. so it'll help compensate for lean conditions a bit, but happily dump a ton of fuel if trims are under 128...

Yeah, as evident by crappy idle @ cold start and cold/warm/hot restart. I could feel it running rich w/o EEHack running.

It runs a lot better now, and adjusting the stoich to 14.3 is what I have done on everything I've tuned.
Today's fuel isn't what it was back in 1994.
I'm no expert, and learn something new all the time from reading/asking/experimentation.
Always nice that folks are so willing to help!

One of these days I need to yank the wideband from my Jeep, and install it on the Caprice.
I already added the wire on the PCM, just have to get motivated enough to crawl under there and weld in a bung.
I have debated just pulling the o2, and using the simulated signal, that has worked in the past for me.
Some say it isn't accurate, and causes issues, I never had a problem doing it that way in past.
I have an Innovate MTX-L and really like it.

After I get the MAF dialed in, I'd also like to tune the VE tables.

[babywag]

the differences in swing voltage is present in the y-body bins too. my best guess is the harness has a bit more resistance on one side than the other, since it's only a few mv.

So just a follow up...I grabbed a spare junkyard pcm several months ago and I pulled the .bin off.
It was actually a 4.3 baby LT1. Same year 1994 even.
Same wiring harness, same 02 sensors, smaller engine(obviously).
However, interestingly enough the o2 swing voltages are the same side to side.

5.7 table and 4.3 table for comparison. Still seems odd to me for the diff in the 5.7 .bin

[kur4o]

Hi,

Can you post the 4.3 bin.
I`ve been looking for it a long time.

[babywag]

Hi,

Can you post the 4.3 bin.
I`ve been looking for it a long time.

Sure can...calibration ID 16199871, from a 1994 Caprice w/ 4.3 VIN 1G1BN52W7RR102356

Any thoughts on why the difference on the 5.7 .bin?