All O2 sensors created equal?

[jim_in_dorris]

What is really interesting is that every single $0d Hac that I have is zero filled from $5BB8 to $5D00. The transmission diagnostics end at $5BB8 and trans parameters start at $5D00. That $81 at $5BC1 in BJYM is strange. I loaded BJYB and it doesn't have a $81 in that location. Nor does BJYL

[dave w]

What is really interesting is that every single $0d Hac that I have is zero filled from $5BB8 to $5D00. The transmission diagnostics end at $5BB8 and trans parameters start at $5D00. That $81 at $5BC1 in BJYM is strange. I loaded BJYB and it doesn't have a $81 in that location. Nor does BJYL

I don't know all the details, but I think the .bin I posted did not need the jumper on the Memcal? I met the vehicle owner on a different board back in 2008 / 2009, we spoke on the phone a few times. I was thinking the vehicle owner mentioned he did not have any hardware mods (PCM Memcal), but it's been years ago. The vehicle owner, nor I did any of the .bin writing. I only helped with a few VE corrections, and emissions delete.

dave w

[EagleMark]

I thought I found something cool? And all I found was something strange...

[JeepsAndGuns]

Looks like yall found the same things I did. I compared that mpfi bin to a stock copy of BJYM and found that difference, plus a crapload of other undefined ones, same as my modded copy of BJYM. I then compared the mpfi bin to a stock copy of BJYL. Comparing it to BJYL did not bring up any undefined differences. Comparing BJYM and BJYL shows the crapload of undefined differences, with the one in question being one of them. So it appears the difference is there even on stock bins. Not counting the undefined items, it appears trans parameters are the only difference between BJYM and BJYL. It also appears to me that the bin may have started as BJYL or something real simmilar.

So, back to the drawing board?

[Six_Shooter]

I did a quick scan through of this thread, and did not see this detailed:

What did you do to the ECM for the MPFI modification?

[EagleMark]

Looks like yall found the same things I did. I compared that mpfi bin to a stock copy of BJYM and found that difference, plus a crapload of other undefined ones, same as my modded copy of BJYM. I then compared the mpfi bin to a stock copy of BJYL. Comparing it to BJYL did not bring up any undefined differences. Comparing BJYM and BJYL shows the crapload of undefined differences, with the one in question being one of them. So it appears the difference is there even on stock bins. Not counting the undefined items, it appears trans parameters are the only difference between BJYM and BJYL. It also appears to me that the bin may have started as BJYL or something real simmilar.

So, back to the drawing board?

There was only one undefined difference. The other buttload were filler of $00 to $FF...

I did a quick scan through of this thread, and did not see this detailed:

What did you do to the ECM for the MPFI modification?

The thread has taken a major turn from O2 sensors. But at this point I think your right and a review of PCM mods may be in order?

[JeepsAndGuns]

This thread, post #6:
http://www.gearhead-efi.com/Fuel-Inj...Information-OD

Followed the instructions in that file. Removed resistors in the pcm, replaced with jumpers, added the jumper to the memcal, and made all changes to the bin as outlined in the file.

[EagleMark]

OK I did find a difference undifined from a true 4.3L CPI to these converted MPFI files but it is in the dissasembly.

 ; SA corr. = (val - bias) x .351 
;
L442F   FCB  0      ;Col. select, 0 = use vac, 1 = use RPM
;

CPI also uses MAT and many tables. Which use "MAT & CTS Blend Multiplier vs. Airflow"

Another one undifined but in the dissasembly, but it is EGR and I don't think is affecting a non EGR vehicle.

;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
; Desired EGR vs. RPM and load
;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;     
L4700   FCB 0   ;EGR load option
    ;0 = vacuum
    ;1 = SD MAP
    ;2 = MAP/Baro ratio

Another EGR, I don't think this XDF has all options for CPI EGR, whatever EGR it uses?

 ;~~~~~~~~~~~~~~~~~~~
;-EGR SA correction
;~~~~~~~~~~~~~~~~~~~
;
L4855   FCB 1  ;EGR load opt. byte, 1=vacuum, 0=%EGR flow
;

OK I'm going to stop listing EGR undefined that all seem to go to a CPI engine...


Stoich in CPI bin is set to 0.3 and TBI is 14.7? But it uses Quasi Closed loop set to 5.0 where TBI is 15.5... SInce "Maximum Temperature for AFR Lookup in Closed Loop" is off do to temp in TBI and on at 57.5... I think there's a lot more going on with fueling? Like Initial O2 voltage is TBI as usual .451 and on CPI bin .000? Minimum BLM 5 in CPI and 105 in TBI...

Then it gets wierd?

All Scantool stuff is differant.

SO after all that I don't think we can use 4.3L CPI for comparison to MPFI!

But I think I found you AE problem? Uncheck AE Limit option, datalog. Then try the other 2 in picture one at a time and data log. Especialy the Sycn Fuel at idle, it says TBI only but it is checked on CPI.

[EagleMark]

Also your desired AFR is a hack in PCM and not applied in yours! It comes from Batterey voltage, so the spikes I have been looking at up and down are something with charging system that needs to be looked at? It could be what is affecting WB02 AFR as well?

EDIT: Voltage are steady at idle vary from 14.2 to 14.5..... on decel they go flat smooth? During high RPM they flucuate quite a bit. WHere does your WB get it's power from?

[JeepsAndGuns]

Interesting findings on the cpi bin, not sure I fully understand all of it, but interesting. Question, you say the cpi 4.3's have a MAT? When I checked the box for cpi/pfi mode during the conversion, its not making the ecm want to start looking for the mat for fueling is it??
Knowing very little to nothing about the cpi 4.3's and how that injection system works, how different is cpi from the pfi I am running?

Interesting find on the battery voltage also, I had to fire up the laptop so I could see for myself in the log. Wonder what could cause it, a bad regulator in the alt? All I have is a cheap parts store voltage guage, it reads good, but I never see any fluctuation in it. I am running a CS144 alt, with a large guage charging wire, through a circuit breaker and then to the battery. Though, the varyation only seems to be just a few points of a volt, is that enough to cause this much of a issue?
I have the system wired as follows:
I used the junction block from the firewall of the tbi truck I originally pulled my harness from. I have a large guage wire coming off the battery to it. I then have the constant 12v power wires for the ecm hooked to it. I also have the fuel pump relay hooked there. I then have another relay I use to power the ignition coil. I then have a 3rd relay that I use to power a 4 gang fuse block under the dash. On that fuse box I have the switched 12v power wires for the ecm hooked to one fuse, the injectors hooked to the 2nd fuse, the heater element of the o2 hooked to the 3rd fuse, and the WB hooked to the 4th fuse. I think I am only using like 5 or 10 amp fuses. System has always seemed to work great, never blown a fuse or had any other electrical issues since the original carb to efi swap.

[EagleMark]

Well that's a good altenator, is your belt good and tight? Seems steadier voltage low RPM, worse higher RPM...

Large gauge wire and stuff sounds good, not sure about a circut breaker in middle? Never did that... grounds good?

I'm not sure about the MAT with CPI checked. I was trying to compare and it got so weird it would not help...

Where is the WB grounded?

Try those changes above, data log each so we can compare, I'm not sure it's the answer?

[EagleMark]

I just got another $0D log and the battry voltage is same, so I don't think there's an issue there.

[JeepsAndGuns]

OK, good to know another log on a different vehicle did the same. I was starting to look for a new alt...lol. It has dual Vbelts for the alt, both are good, tight, and not very old.
The WB is grounded to the engine (unused bolt hole on the back of the intake)
The curcuit breaker I added just cause I am the paranoid type and I like to make sure important stuff gets protected. I like the idea of the resetable circuit breaker than something like a large fuse or fuseable link. The circuit breaker is in between the alt and the battery, and is rated for 130 amps before it trips.

I will try those parameters and report back. Just same as always, it will be the weekend before I get time to do it :/

[JeepsAndGuns]

But I think I found you AE problem? Uncheck AE Limit option, datalog. Then try the other 2 in picture one at a time and data log. Especialy the Sycn Fuel at idle, it says TBI only but it is checked on CPI.

Ok, had some time this afternoon to fiddle with it. I loaded it up with the emulator and tried each one of those one at a time while also datalogging. I changed each one at idle then drove a bit. Each one made zero difference. Idle did not change, idle afr did not change, running, accel, decel did not change, and running, accel, and decel afr did not change any either. Afr still all over the place. Seeing no difference I didnt even bother to record a log.

So lets go back to the basics. Are there any mechanical issues that could cause this? I mean the thing runs great, and if I didnt have a WB, I wouldnt have even known the afr is all wonky. But since I do have one, and can see it, it irks me a bit.

Started working on a 7427-7730 adapter harness.......

[dave w]

Ok, had some time this afternoon to fiddle with it. I loaded it up with the emulator and tried each one of those one at a time while also datalogging. I changed each one at idle then drove a bit. Each one made zero difference. Idle did not change, idle afr did not change, running, accel, decel did not change, and running, accel, and decel afr did not change any either. Afr still all over the place. Seeing no difference I didnt even bother to record a log.

So lets go back to the basics. Are there any mechanical issues that could cause this? I mean the thing runs great, and if I didnt have a WB, I wouldnt have even known the afr is all wonky. But since I do have one, and can see it, it irks me a bit.

Started working on a 7427-7730 adapter harness.......

When I tune a '7427 PCM with a WBO2, I disable BLM update. I wonder if your WBO2 will stabilize if you decide to experiment with BLM update disabled?

dave w