Six_Shooter

iTrader: (2)

I've been reading through some threads on using $OD to control MPFI and and an electronically controlled tranny.

I have a friend that wants to convert his '70 Cutlass from TBI to MPFI, and already has the E-trans (4 bbl TBI, running from a 7060).

Now for those that are numbers matching savvy you've already figured out he has a 4L80-E.

From what I've seen the 427 will control MPFI, and an E trans, but have only seen it controlling 4L60-E.

So what would have to be done to use $OD to control the 4L80-E?

FWIW I don't know much about E-tranny control, I'm a "row my own" kinda guy. Would it be as simple as matching pinout, or maybe just matching settings between $OD and $85?

I have looked through the $85 hack that I have and could not find a TBI/MPFI flag like $OD has, I was hoping it could be that simple. LOL

gsjmtntman

I believe the $0E code is used to run the 4L80E, but it is usually paired with a 7.4L motor. You may be able to get a good starting calib. from the 0E, then tweak it to your preferences. HTH

Six_Shooter

iTrader: (2)

Yeah another member has mentioned that to me. The hack shows that there is a TBI/CPI/PFI flag.

The engine is a 455, so it should be pretty close in current form.

I just have verify compatibility with a '7060.

junkcltr

iTrader: (1)

It also depends on what year 4L80E he is using. They changed the TCC or Force motor PWM rate for 1994 to 1995. So the code you use has to match the trans.

Don't forget to add the MEMCAL jumper wire when setting the CAL to MPFI mode. May need to short the injector driver sense resistors for proper high-z injector operation.

Fast355

iTrader: (2)

$85 is the code for the 7060 ECM.. It comes in both small block and big block flavors, both run the 80E.

$0E and $31 are both 7427, 8625, etc codes for the 80E. You can have them both in small and big block calibrations. I am pretty sure there was even a 4.3TBI/4L80E combination used in the G/P vans.

Memcal Jumper and Injector sense resistor bypass are BOTH needed to run 8normal MPFI injectors.

dimented24x7

iTrader: (2)

You need to change the shift solenoid state table so the trans will shift properly. Not sure about the torque converter, though. The $0D does not have the routine for the TIS input, so only the standard TCC routines can be used. Oldred is running his truck with a 4l80-E and $0D code, and so far it sounds like it works OK.

Six_Shooter

iTrader: (2)

Could you assume I know nothing about automatic tranny control, and expand on what you are saying here? The knowing nothing about automatic trannies isn't far from the truth.

I'll open the xdfs (and bins) for the available codes later, but would it be as simple as copying the values found in an 80E calibration into a 60E calibration, or more specifically from the known working cal, into the new "MPFI" cal? Obviously I won't be able to use the copy from compare function of TP RT, since I would assume that all available masks wouldn't use the same location for this table.

What is a TIS input?

Thanks.

Six_Shooter

iTrader: (2)

I'll bring that up and find out what year cal he has been using and the information about the tranny.

93V8S10

What about swaping to a 7427, 8625, etc and using the $0E code? Might be simpler in the long run.

Six_Shooter

iTrader: (2)

That's what I'm thinking of, I just would like to gather all information I can.

Is there really a need to swap the ECM from a '7060 to use $0E?

93V8S10

Wish I know for ya, but I don't.

Six_Shooter

iTrader: (2)

I guess my test bench will need to be fired up.

junkcltr

iTrader: (1)

I did some 427 ECM code compares years ago. I seem to remember the 454ci w/ 4L80E compare to a few 350ci w/ 4L60E bins I had only had CAL differences. The code was the same. That means you could insert the trans. CAL or engine CAL into which ever bin you wanted.

Do a "fc /b bin1.bin bin2.bin > difference.txt" in an MSDOS command window and see if the code is different in the two bins you want to use.

GMEFIGUY

I've been runnning a 7427 controlling a TPI 8 cylinder for 6 months now. It runs fine on the road but has a bad idle in closed loop. Idles fair with O2 wire pulled out. I've done the MEMCAL jumper (pin 56 to zero volts) and have jumpered the sense resistors on the injector traces.

Since the MEMCAL jumper is supposed to make the injectors fire every 4th DRP, on a hunch I decided to connect a DVM to the injector outputs with the DVM set to frequency mode. At 600 RPM idle the 4th DRP frequency should be 10 Hz. I get 40 Hz on the ignition module ref high wire although it jumps around a lot at idle. On the green injector pin I get the desired 10 Hz but on the blue injector pin I get 20 Hz. This means the injector outputs are not both firing on the 4th DRP. One is but the other is still firing at the TBI rate of every 2 DRPs. Does this mean I need to drive all 8 injectors on the blue pin so that they all fire on the 4th DRP? This would seem to make sense because the 1227730 has one output for all 8 injectors and it fires every 4th DRP with the MEMCAL pin 56 at zero volts. Also IIRC, the CPI V6 only uses one injector in the fuel pod but I'm not sure which pin drives the injector since I haven't looked at one that close. Bottom line is do I have to use only one injector driver to have them fire in double fire batch mode with a MPFI V8? Anyone have any evidence to dispute this?

TIA

dimented24x7

iTrader: (2)

Heres how the injector drivers work. The MEMCAL actually drives a counter within the PCMs code. There are two base controllers for the inector drivers. One is the automatic alternating firing controller for the TBI. The second is a pair of software controlled injector outputs that the PCM uses to control when and how long the injectors fire. The drivers are capable of being completely controlled by the software with no external inputs. But, for some reason GM chose to allow teh memcal to control the injectors. What the memcal does is alter the rate that an internal DRP driven counter runs at. This determines when the injectors will fire.

Now, provided you remembered to set the correct option bit for PFI/CPI, both injector drivers are set up to fire together at teh same time. There is another option bit that controls the injector drivers individually for bank and CPI mode, but that one should not be set. The correct settings are:

$400B - bit 0 should be set to 1 and bit 4 set to 0.

$400C - bit 3 set to 0.

Double check to be sure that you have those set or cleared first before investigating further.

junkcltr

iTrader: (1)

GMEFIGUY,
The $0D code doesn't operate like the 747 / 730 / 749 code stuff. It is just like dimented24x7 posted. The fuel mod bits in the bin need to be set appropriately to get the fuel mode right. I have a 350 TPI running off the 427 ECM also. It idles fine.
I had to do the most researching & tweaking of the adaptive spark stuff for the manual trans. I am using. The other hard part was figuring out all of the fuel modes and which bin to start with ( CPI V6 or TBI V8 ) for the stock engine - 350ci reman 8.5:1 compression TPI intake.

The other thing is reversing the fuel injector constant equation to get it right for the 8 TPI injectors.

GMEFIGUY

I've read everything I can on this forum concerning 7427 V8 MPFI conversion and can't get this working right including TBI to TPI.doc. My bits are set per the above but I'll post the contents of $400B through $400D and would appreciate if anyone with a sucessful V8 MPFI install can tell me the differences.

$400B - C5 11000101
$400C - 17 00010111
$400D - A2 10100010

Also have injector constant set for 52 # /hr with eight 26 # injectors.

Anyone have a DVM they can connect to pins A9 and A16 to see if they are getting the same firing frequency as I am. Set to Hz scale by the way. Basically A9 is half of A16 at all loads. 10 Hz and 20 Hz at 600 RPM idle.

TIA

dimented24x7

iTrader: (2)

In order to verify the operation of the injector drivers, you may need to use an O-scope. The reason is taht there are two sets of driver circuits driving the transistors that fire the injectors. The one for TBI could still be sending small but detectable pulses to the circuit, causing your DVM to trigger. Hooking it to an O-scope would tell for sure.

Have you compared plugs from each side of the motor? If the injectors on one side are firing 2x more, then you should have one bank with black, sooty plugs.

gsjmtntman

Did you get this sorted out GMEFIGUY!