Newbie question , re; mem-cal compatability; TBI to MPFI ??

[jim_in_dorris]

Six_Shooter
I am not trying to start an argument here, just learning stuff. My hack of $0d has a CFI/PFI mode switch at L400B that is tested in several places in the code. Am I mistaken that that bit turns on CFI mode?
;==================================~
; SET UP HARDWARE FOR CPI/PFI MODE
; or TBI MODE
;==================================~
LDX #$B93A ; TBI mode
LDY #L400B ; mode word
BRCLR 0,Y,#$01,L723A ; Bra if b0=0, In TBI mode
;================================================= =================~
; -In CPI/PFI mode
;================================================= =================~
LDX #$B91A ; CPI/PFI fuel mode
;================================================= =================~
;-Here to store
;================================================= =================~
L723A STX L3FFC ; I/O D Port
JSR LF08A ; RTS, Delay

[Six_Shooter]

No, you're not mistaken, that's how the code works, but there is also a hardware side of it that needs to match and sets the injector firing scheme. The hardware side is part of the RFD side of the MEMCAL, this is why people talk about jumpers for cylinder select, when modifying a 6 cylinder MEMCAL for use with a V8, similar changes need to be made to switch between TBI and MPFI or CPI fueling.

[jim_in_dorris]

ok, is that sort of like modifying the drivers and memcal to do tpi with a tbi prom? What I would think then is if he took the tbi memcal code, modified it to CPI/PFI, and put the prom in the CFI memcal then wouldn't that accomplish the same thing? The RFD side of the memcal would be for CFI, the code turned on the CFI, and all the tables would be set for manual tranny?

On the other hand, switching from auto code to manual code may be fairly straightforward, but as I recall, all the spark and fueling tables are different between them as well.

[romac55]

What I'm trying to accomplish is simple ; I'd like to dump the ECM's 4L60E trans inputs , as I'm changing to a manual 4-speed . Can I just do that with a chip change to one from a manual trans truck (same 16187427 ECM) ? There's so much I don't know , kind of like basic education ; the more you learn , the less you know . LOL . Thanks for your wisdom . Be safe...Bob.

[Six_Shooter]

ok, is that sort of like modifying the drivers and memcal to do tpi with a tbi prom? What I would think then is if he took the tbi memcal code, modified it to CPI/PFI, and put the prom in the CFI memcal then wouldn't that accomplish the same thing? The RFD side of the memcal would be for CFI, the code turned on the CFI, and all the tables would be set for manual tranny?

On the other hand, switching from auto code to manual code may be fairly straightforward, but as I recall, all the spark and fueling tables are different between them as well.

That's what I've been saying all along use the MEMCAL that has an original configuration for the induction system, in this case, CPI. Then program an EPROM for CPI with a manual trans, don't worry about what the original PROM was programmed for, it becomes null and void in the end. The LHM and RFD (and knock filter) side of the MEMCAL are the parts that remain connected to the ECM in the end. Even if there are large changes between an auto cal and a manual cal, there are editors for that (Tuner Pro). ;)

What I'm trying to accomplish is simple ; I'd like to dump the ECM's 4L60E trans inputs , as I'm changing to a manual 4-speed . Can I just do that with a chip change to one from a manual trans truck (same 16187427 ECM) ? There's so much I don't know , kind of like basic education ; the more you learn , the less you know . LOL . Thanks for your wisdom . Be safe...Bob.

No, you can't use the TBI PROM on the CFI MEMCAL to accomplish what you want. The BIN/PROM is still programmed for TBI and will at the very least pop up a CEL (Check Engine Light) for cyl count error, possibly MEMCAL or PROM error.

The solution is simple. Use the CPI MEMCAL and program an EPROM with a CFI and manual trans bin. I'm pretty sure you will need to set-up the CPI bin for manual yourself, I don't recall there being a CPI with a manual trans from the factory.

You can use the compare function in Tuner Pro to find differences between auto and manual bins. Some stuff that would be TBI specific you would have to ignore.

[PJG1173]

I don't recall there being a CPI with a manual trans from the factory.

using a spread sheet I downloaded from the moates website for BCC lookup there were no L35/Vin code "w"/CPI bins listed with a manual transmission. looking up some of the CPI BIN's on BCC find listed All under transmission so without downloading some bins and looking there's no telling. not to say that it dosn't exist just I've never came accross any.

OP, I've looked at a lot of CPI bins and their timing tables are much more aggressive than a TBI, and there are tables that only CPI engines use. like said above it would be better to use your CPI bin and copy the manual trans settings from another bin. Also just for your info when you are doing some searching or talking on other forums that are 4.3 centric most people will know what you are talking about if you say vin "w" or CPI. You will probably get flamed for refering to it by its real GM name (which sounds like an oxymoron if you ask me) or calling it a vortec.

[romac55]

using a spread sheet I downloaded from the moates website for BCC lookup there were no L35/Vin code "w"/CPI bins listed with a manual transmission. looking up some of the CPI BIN's on BCC find listed All under transmission so without downloading some bins and looking there's no telling. not to say that it dosn't exist just I've never came accross any.

OP, I've looked at a lot of CPI bins and their timing tables are much more aggressive than a TBI, and there are tables that only CPI engines use. like said above it would be better to use your CPI bin and copy the manual trans settings from another bin. Also just for your info when you are doing some searching or talking on other forums that are 4.3 centric most people will know what you are talking about if you say vin "w" or CPI. You will probably get flamed for refering to it by its real GM name (which sounds like an oxymoron if you ask me) or calling it a vortec.

We changed the spider not 2 weeks ago on a 94 Blazer with "CPI" and it was a 5-speed . What trans inputs can there be for a manual trans ? There's no shift solenoids , no trans temp or pressure and no TCC lockups . I can see the VSS input , but i've made my own 40-toothed wheel for that . Don't all the trans inputs just get stored in the mem-cal ? Would just using the manual 94 Blazer CPI chip do the same thing as re-programming ? I haven't sent my order to Moates yet , but don't enjoy watching $400+ go out the door just for this one ECM . The years of CPI are about done it seems. Be safe...Bob.

[jim_in_dorris]

Will he have to change more than these 2 mode words? I haven't done a manual tranny, but as near as I can see, these are the only 2 places to set a manual tranny. I do know that he may not need shift light enable.

L400E FCB $00 ; MODE WD, AFR 4 0000 0000
; b7 1 = not used
; b6 1 = not used
; b5 1 = LATCH ERR 45
; b4 1 = USE L496F WITH ASYNC FUEL DELIVERY
; b3 1 = VAR TUNE CNT'L
; b2 1 = SHIFT LIGHT ENABLE Do not use with 700R4
; b1 1 = USE ALT CMAP Vs. MAP LD FOR FUEL CUR HYST PAIR
; b0 1 = USE ALT CMAP Vs. MAP LD & AD MAP FOR BLM ENABLE
;================================================= ==
L400F FCB $58 ; MODE WD, DIG I/O 0101 1000
; b7 1 = MAN, (0 = TCC)
; b6 1 = TCC (Non Elect xmish)
; b5 1 = not used
; b4 1 = CONV OVER HEAT
; b3 1 = KNK RETARD
; b2 1 = A/C CLUTCH CNT'L, 0 = VAR TUNE
; b1 1 = not used
; b0 1 = 1 DO RPM/MPH LMT