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.

Attachment 11008

Here is before.

Attachment 11009