va454ss

iTrader: (1)

I lucked out. Grabbed a BBC conversion used with 29 lb injectors (502) for $400.

Grumpy

There's more floating around then that. My *hint* was do to some more searching.

chris1

Grumpy,

Your playing Yoda to Skycrawler. I am using the 0D ECU file that 89350STRO, Stevie, HaulnA$$, and other very talented people here built :hail: in TunerPro, and if it's got a check box for injection type I missed it. I have chewed through some serious bandwidth with the search function trying to figure things out on my own. What pray tell ECU def. file / BIN combination will work in a 7427 PCM for MPFI?

Since my original post the speed shop and I have changed the componentry quite a bit which will raise the power level to around 475hp @ 6000rpm, properly tuned of course. . I am open to ideas on how to best inject this motor. Hardware, ECM{s} and software combinations. Or do you guys think I should connect a TPS to a carburetor, zero out the fuel tables, modify the spark table and shift points and run it that way untill HaulinA$$ and the rest of the pro's hash out what is possible with the 7427?

Thanks
Chris

HaulnA$$

Look at bit 0, AFR mode word 1, in the "Flags" list. If the bit is set, CPI/PFI mode is selected, not set, TBI mode.

Grumpy

A PCM consists of 3 items, software, firmware, and hardware.

Flipping the flag sets the software, now you need to check on the firmware (memcal).

There was no truck PCM that I'm aware of the was port. There was a SS454 guy that posted something about a memcal rewire to set it for port.

HaulnA$$

This same PCM (16197427) was used in the 4 cyl. S-10 trucks in a port configuration, the V-6 S-10 trucks in TBI and CPI configurations and the fullsize trucks in a TBI configuration. There are a few guys on the truck boards running the Edelbrock MPFI conversion claiming smoother running engines after putting the PCM into CPI/PFI mode. I, myself, am skeptical until I prove it to myself. I have been tuning on this PCM for a while on a stock engine in anticipation of using it to control a Holley 4BBL 900 CFM TBI on a 383 stroker that is on the engine stand now using a quad P/H injector driver PCB. Once completed, the next phase will be a custom port setup or maybe a HSR with the same PCM in control, even if I have to mod the code. I hope to have my PCM bench completed within a couple of weeks so I can put the O-scope to it and play with the injector firing schemes. As I dive into it, I plan to share my findings and I am positive I will need much help from the members here.

chris1

I thought I would give an update on my project. The engine is still a few days from being completed, had to order different rockers to fit. I got my box of goodies from Craig on Friday! What a blast the 4l60e is to program. I have been tuning it to work with the new engines higher power band. I am wondering what line pressure modifications I should do? There is very little information out there on the subject. From what little I could find most guys are running around 200-240 lbs. max., which is more than three times my factory bin settings, and zeroing out the line pressure mods. If anyone has experience please chime in.

I have decided to run a carburetor to break in the motor. Should I just empty all of the fuel tables one at a time, or is there an easier / better way to keep the injector drivers from firing?

The best TPS sensor I could find to use so far is the Holley 543-29. I plan to fabricate a bracket and control rod assembly. It's the only one I can find that has an arm and connects to my factory harness.

Chris

Grumpy

Now that's interesting, ie being used in a 4 cyl port. But, that might be using a TBI injector firing strategy.

Yepper, on something like this being a skeptic is critical.

A bench and scope are the only true ways of getting to the truth.

va454ss

iTrader: (1)

Got a link?

Grumpy

On my 4L8E, it has a table for shift execution times. I dropped then all 50%, and that made alot of difference in how the tranny shifted. I'd work on that before line pressures. In large part it's the slippage between shifts that eats up the clutches, and discs.
I think I raised the line pressures, maybe 10% on the average.

HaulnA$$

In the $0D hack, at the beginning of the algorythym, the first item of business in the code is to determine whether to run in TBI mode or CPI/PFI mode. Two seperate batches of code. The hack references "double fire" and other clues in the TBI section. I haven't figured out the code yet. My PCM test bench is nowhere near finished and it has been 20 years since I studied Motorola microprocessors in college and we programmed in machine language, my assembly is rusty but I'm working on it in my so called spare time.
Here's one that you just happen to have participated in. http://www.fullsizechevy.com/forums/...d.php?t=113849

chris1

Grumpy,

The 4l60e does not use a shift execution time table unfortunately.

Anyone have advice for best way to shut down the injector drivers, empty the tables or use flags? Is there anything else I should be taking care of in the Bin specific to running a carburetor ie. no IAC?

Thanks
Chris

HaulnA$$

I beg to differ. This is from the $0D hack and verified in many . bins with a hex editor.

***************************************************
* BDWM/9042 P/N 16189041 10-11-1993 15:54:04
* 3/4/94 WAS
*
* 5.7L V8 C1 M30 GT4 (3.73) NB2 NB6 TIER 1
* ECM TYPE $0D
* ECM P/N 16196395 ECM
*
* 4L60E XMISSION PARAMS
* TYPE $0D ECM
* 5.7l L05
*
***************************************************

********************
* DESIRED SHIFT
* TIME
********************
;---------------------------------------------
; DESIRED SHIFT TIME
; 1 -> 2 SHFT
;
; 10-07-1997 Dissassemby of BDWM Lines= 17
;
; TBL = .04 * msec
;---------------------------------------------
ORG $658F ; msec %TPS
;---------------------------------
L658F FCB 34 ; 850 0.0
L6590 FCB 34 ; 850 6.3
L6591 FCB 29 ; 725 12.5
L6592 FCB 30 ; 750 18.8
L6593 FCB 33 ; 825 25.0
L6594 FCB 35 ; 875 31.3
L6595 FCB 35 ; 875 37.5
L6596 FCB 33 ; 825 43.8
L6597 FCB 33 ; 825 50.0
L6598 FCB 35 ; 875 56.3
L6599 FCB 35 ; 875 62.5
L659A FCB 34 ; 850 68.8
L659B FCB 35 ; 875 75.0
L659C FCB 35 ; 875 81.3
L659D FCB 36 ; 900 87.5
L659E FCB 37 ; 925 93.8
L659F FCB 37 ; 925 100.0
;---------------------------------------------

;---------------------------------------------
; DESIRED SHIFT TIME
; 2 -> 3 SHFT
;
; 10-07-1997 Dissassemby of BDWM Lines= 17
;
; TBL = .04 * msec
;---------------------------------------------
ORG $65A0 ; msec %TPS
;---------------------------------
L65A0 FCB 32 ; 800 0.0
L65A1 FCB 32 ; 800 6.3
L65A2 FCB 32 ; 800 12.5
L65A3 FCB 34 ; 850 18.8
L65A4 FCB 34 ; 850 25.0
L65A5 FCB 34 ; 850 31.3
L65A6 FCB 34 ; 850 37.5
L65A7 FCB 34 ; 850 43.8
L65A8 FCB 34 ; 850 50.0
L65A9 FCB 38 ; 950 56.3
L65AA FCB 38 ; 950 62.5
L65AB FCB 38 ; 950 68.8
L65AC FCB 38 ; 950 75.0
L65AD FCB 40 ; 1000 81.3
L65AE FCB 40 ; 1000 87.5
L65AF FCB 40 ; 1000 93.8
L65B0 FCB 40 ; 1000 100.0
;---------------------------------------------

;-------------------------------------------------
; DESIRED SHIFT TIME
; 3 -> 4 SHFT
;
; 10-07-1997 Dissassemby of BDWM Lines= 17
;
; TBL = .04 * msec
;---------------------------------------------
ORG $65B1 ; msec %TPS
;---------------------------------
L65B1 FCB 32 ; 800 0.0
L65B2 FCB 32 ; 800 6.3
L65B3 FCB 32 ; 800 12.5
L65B4 FCB 32 ; 800 18.8
L65B5 FCB 32 ; 800 25.0
L65B6 FCB 32 ; 800 31.3
L65B7 FCB 32 ; 800 37.5
L65B8 FCB 32 ; 800 43.8
L65B9 FCB 32 ; 800 50.0
L65BA FCB 32 ; 800 56.3
L65BB FCB 32 ; 800 62.5
L65BC FCB 32 ; 800 68.8
L65BD FCB 32 ; 800 75.0
L65BE FCB 32 ; 800 81.3
L65BF FCB 32 ; 800 87.5
L65C0 FCB 32 ; 800 93.8
L65C1 FCB 32 ; 800 100.0
;---------------------------------------------
**********************************************

You may need to ubdate your .ecu file to edit these tables. HTH

chris1

HaulnA$$

I am using 0d v1_02.ecu, what updated ecu file would allow me to see and edit the shift timing tables?

And any input regarding the rest of my quandary would be appreciated.

Thanks
Chris

HaulnA$$

I meant that you need to update your .ecu by modifying it to include those tables. Check out this tutorial on the TunerPro website. It explains how to do this. As for the other stuff, if you leave the injectors disconnected, the drivers will draw no current. If you must disable them in the .bin (I can't imagine why you would need to do this), try a 0 injector constant. For the IAC and other sensors or inputs you don't use with a carb, just disable the error flag for whatever code you get as long as it is not tranny related. To dial in the line pressure, do as Grumpy said and start at 10 % across the board. I have found that 10% at the low TPS/low MPH areas is good and ramping it up to 25% at the high TPS/high MPH areas works well, just remember, the numbers in the line pressure tables are not actual PSI, just a reference value. With your engine, you may consider a shift kit.

chris1

HaulnA$$

I cant believe I missed that tutorial! I'll stare at your post with the timing address's and the editor for awhile and it will probably click. I have only been at this a few weeks. I just toasted my first chip five days ago. If I can figure out how to add the shift timing tables to the 0D ecu definition file I will post a new ecu file to to Craigs site, unless someone else that actually knows what there doing has an extra couple of minutes. The only table adding I know how to do I will be perfroming this afternoon when I add a few leafs in the the dinning room for extra family .

I adjusted my line pressure 20% accross the board, I figured that was safe. I looked at the TCI Tcom software which has a normal to performance Lb. kick field and it is set to 25%. There are guys over at the LS1TECH forum that are running pressures up around 218-240!

When I destroyed my transmission last year it was rebuilt using all the better guts, and Transgo shift kit. It does not hit 2-3, 3-4 nearly as hard as need be. With your help hopefully I can get it there with the software, or else it will take a trip the trans. shop for some more hardware next week before the motor goes in.

Thanks much
Chris

Stevie

The only thing I changed in my transmission programming was the normal shift points vs speed, and the line pressures. After a lot of fiddling with the shift point speeds I really like the way it drives. As for line pressures, when I've had them too high it about snapped my neck when it shifted while I was just driving around town. Although that's a bit hard on the driveline I doubt it would hurt anything. However when the line pressure is too low it seems to gently (and slowly) slide from one gear to the next. At high power this is akin to letting the clutch out gently on a standard while making lots of power. This is hell on the clutches in the tranny. I used a line pressure table given to me by someone on this board quite a while ago and its just fine. It is a lot more than 20% above the stock pressures. If you want, I can send the bin

Steve

Grumpy

Can I suggest trying dropping the shift times?. It's slippage during the gear change the developes the majority of heat. A 250 PSI line pressure, and allowing .3 sec for a gear change is doing alot more damage, then .15 at 150 PSI. (examples are approximates, to illustrate a point)

Stevie

You're right on the effect of shift time Grump. I baby mine around mostly but I will play with the shift time and see if I can feel the difference. Line pressure changes are definitely noticeable.

Steve

contactpatch

Perhaps someone could write an overview,
of how the computer uses TPS to control
TCC lockup and shiftpoints.

Thanks

Swats

Not to get off topic. But I have a 1995 Chevy S10 SS. It has the CPI injected v6 backed be a 4l60E trans and I would like to do some basic tuning on it. What would it involve? I know I need a cable and software. I also have access to a laptop. By I am getting lost and this mask thing. I am asking here because I read this thread discussing the use a of pcm from a cpi truck. Can some one give me some help?

chris1

Steve

I would love to have a look at it! As I had mentioned earlier some of the guys over at LS1TECH tech are running pres. over three times higher than what my factory bin settings are. Bumping mine up 20% is hardly noticeable. I will try to figure out how to add the shift timing tables that HaulnA$$ pointed out to the ecu file when I get some spare time over the weekend.

Thanks
Chris

HaulnA$$

Basically the PCM uses the TPS, VSS and temperature to control shifts and TCC lockup. Here's how I believe the tranny tables work from my experiments. I agree, the desired shift time tables affect the life of the tranny parts. Some of the later $0D calibrations I have seen have the 2>3 and 3>4 desired shift time tables zeroed out leading me to believe that they are not absolute. The shift point vs TPS vs MPH tables determine the normal shift MPH at a given TPS and affect overall drivability and can tune the e-shifting to the operators driving style. The kick down shift tables (basically WOT for e-tranny's) determine when the tranny will shift up or down when a high TPS qualifier has been crossed. Kick down mode is based on MPH and RPM settings which both must me met before shifting occurs . The main line pressure tables determine normally applied pulse width modulated line pressure via the force motor. Note that the numbers in the table are not actual PSI, but a close representation factor as there is no way for the PCM to measure PSI. Line pressure determines clutch apply force and can affect shift firmness. On high torque applications, increasing line pressure can reduce slippage. The line pressure modifier vs TPS and MPH tables offset the main line pressure tables for each gear in normal mode and kick down mode based on speed and TPS. Lastly, the TCC cals. The TCC MPH engage/release vs TPS tables control what MPH engages or releases the TCC at a particular TPS. There also TPS constants that will release a locked TCC on large TPS changes in accell/decell. There are hot and cold engine and tranny modifiers to some of the mentioned tables. There is also an adaptive learn mode (basically closed loop BLM's for e-tranny's) but I have not seen this enabled in any calibrations. I think that about covers it. I believe tranny tuning must be aproached just like engine tuning, as a system. HTH

Stevie

That's pretty much my understanding also. But the question is, how does the desired shift time table affect the shift times? When it comes time to shift, the pcm grounds an input which picks up a solenoid in the tranny. That's an on/off function which cannot change the shift time. There is an error flag in the datastream called "ERROR BETWEEN DESIRED AND ACTUAL SHIFT TIMES FOR LATEST 1-2 UPSHIFT". The pcm knows when a shift is actually completed because a switch in the tranny picks up. I suspect the desired shift time table is used only to compare against and set the error and not actually change the time. Whaddya think?

Chris, I uploaded the bin onto Craig's site. It is called: version 1.7.3a.bin

Steve

HaulnA$$

You could be right seeing as some of the .bins I have seen have some of the desired shift time tables zeroed out. I'll have to play with that whenever I finish my test bench. At the rate I am going, that may not be til next year.

chris1

Steve,

Thanks for the bin.

It was very helpful to look at a modified file to give me an idea where I need to go, not only for the the shift pressures but also timing. I bumped up my shift pressure to resemble the 1.7.3a. bin and I cannot tell much of a difference, still seems pretty soft. Oh well, the vehicle is going to the trans shop anyway to get the Corvette servo installed and I will ask what they can do hardware wise. Several people end up going to the 4L80E because they tire of toasting 60's. The new motor is ready to install and I may find myself in the same boat if I dont get the nice comfy 2-3, 3-4 mush shift firmed up a bunch, with throwing twice the horses and an additional 2500 rpm of useable powerband than it has seen before it may not last long!

I played a bit with the timing and found that the ol' tbi motor loves about four degrees more throughout. It drives like a different vehicle with so much more snap and power. With just the little bit I have done with shift points and timing, I could have probably lived with the stock motor a while longer.

I have come to wonder why the hotrod guys are not using the factory pcm's in mass. With the ability to dial in exact shift points and timing why wouldnt everyone run one? Procomp makes a late model dual plug dizzy that retails around a hundred bucks, a 40-50k late model coil is around forty bucks, 7427 pcms are a dime a dozen, throw in a few sensors and some goodies from Craig to allow you to dial everything in and your set. Plus the ability to hook up to your aldl port and monitor everything. Or is this our little secret, and I should solemnly swear from this point on to never speak of this again.

Chris

chris1

Well

I finally had time to install the new motor. Now to get it running! It started right up after about half a spin, ran it from about 2500 to 3k rpm with some gentle and fast runs up to around 5k for 30min, set the idle mixture screws on the carb. and tried to drive it. It just sputters and chugs with no power! I threw my timing light on it and noticed I have no timing advance untill the rpm's are over 4k, and then only about 4 additional deg. When I picked the motor up from the speed shop they had installed a plug where the knock sensor goes. for my initial run I clipped the wire and set the knock retard in my bin to 0 Deg.. I have my map sensor plumbed to the power brake Vac. source on the carb with about 3 inch. of hard line, which should be seeing full vacuum. My oxygen sensor is laying on the bench for the time being. I also put in an aftermarket Procomp dizzy. Today if I can find time I will run a 3.9k resistor from the knock sensor wire to a good ground on the motor, and try my factory dizzy. If anyone has an idea why I would not be getting ignition advance please chime in!

Thanks
Chris

Grumpy

Nope, the vacuum booster is a controlled vacuum leak.

MAP needs it's own line.

chris1

Grumpy

The Map sensor line is connected to the brake booster supply nipple on the back of the carb., The vacuum line from the brake is connected to a fitting on the intake manifold. I am not running both from the same fitting.

Are you saying that the brake port on the carb. does not see full vacuum?

Thanks
Chris

chris1

I figured out the main cause of my stumbling problem. I had installed short reach stone cold plugs, NGK R5673-9 that I had read somewhere as the best plug for the Dart 215 Iron Eagles with 9-10 comp.

I also figured out my timing issue. Upon further review with a VOM my map sensor was putting out just over 2 volts, right were it should with my motor making an estimated 17 Hg of vacuum. The reason I was not getting much spark advance is because in my almost stock spark tables that area of vacuum only has about 5 degrees of avance from 1200 to 4k rpm! I have been adding in more timing slowly and the motor is starting to come to life. If anyone can point me to a table that has been built for a motor with around 17Hg Vac. that I can study I would appreciate it. I am not sure If I should build the advance aggresively within the current no load map range and smooth it to the top of the graph, or just add it more slowly at higher map ranges?

Thanks
Chris

chris1

Guys I still need a little help please.

Long story condensed, The motor ran out of oil pressure with less than fifty miles on it. It had completely destroyed all the bearings due to a problem that started with the rods, Eagle stood behind the problem and replaced everything. I now have everything back together and am trying to tune.

The major problem I have is ignition timing. The motor is running a Carburetor with an external TPS. I have the MAP sensor connected to full manifold vacuum, both sensors seem to be functioning fine. I have edited my spark tables for a more aggresive advance curve. The motor starts and runs O.K. but when you nail the throttle in park or when going down the road at steady speed it falls flat for about a second and then revs. I installed a larger pump discharge nozzle thinking it just needed more pump shot, that didn't help or hurt. I then grabed my timing light to take a closer look at what the timing was physically doing, and my spark advance is working ABSOLUTELY REVERSE of what it should be doing! I have my idle timing set at 34D "thats what it wants" and when you jump the throttle under load to get some feed from the map sensor going the ignition RETARDS about 12 degrees! Before I dig in this weekend I would appreciate any suggestions on where to start? What could cause this? I have an aftermarket Procomp dizzy but I have never heard of a module working backwards!

Thanks
Chris

chris1

Update

I found time this afternoon to change the ignition module, and I noticed something that may help diagnose the problem. From an idle position if I move the throttle very quickly to where the motor runs at around 4k rpm and hold it there, what I notice with a timing light is that the timing initialy drops off by about 10-12 Deg. for around a half second {while the engine is bogging} and then climbs to an advanced position 6 to 7 Deg. higher than the idle setting. It appears the motor is getting rpm based advance, but when the throttle is opened quickly and the vacuum drops the ignition is retarding instead of advancing. Thanks for any help.

Chris

RBob

iTrader: (1)

That is correct. When you snap the throttle open the manifold pressure increases which in turn has a lower SA requirement and is set that way in the SA table.

Once the RPM increases the the manifold pressure decreases and the SA comes back in. Check the SA table in your bin. You'll see this.

RBob.

chris1

Thanks RBob

I have so much to learn. I would guess that with the engines semi choppy idle I am going to have to completely rebuild my tables to keep the timing from falling off so much when the throttle is used aggressively?

Chris