I have been playing with a 730 ECM $8D code in a car with boost. It has not FMU, but 42 #/hr injectors and stock fuel pressure.

The $8D code seems useless for boost applications even with an FMU. Under part throttle when under boost it is in closed loop and cuts the pulsewidths down to maintain 14.7:1. Real bad under boost. I am putting in the $58 code tomorrow. I am curious how the boosted with FMUs uses the 730 $8D code. They only way I see it working is running open loop ALL of the time.
I can run 30% throttle opening with 5psi of boost and it closed loop makes it want to detonate in a bad way. Is open loop the only way you boost guys get it to run correctly?

J

 

Isn't PE mode enabled by the time you get to MAP values greater than 100 kPa, anyway? I would guess (but not speaking from experience) that you're always going to be in open loop under boost as a result of the PE enable.....? If so, that's where the FMU is going to help.

 

I cant remember what has to be set before enable PE in 8D but
just go for $58 code and never look back........I did

/N.

 

42's are rather hard to deal with at short pulse widths, a visit to Turbobuick.com will verify that.

The only reason for running closed loop is if you have a converter.
If you enjoy tuning, and are using a WB, then the winter summer fuel changes are like 25 mins worth of tinkering to optimise the AFR. And not all cars like cruising at 14.7:1.

 

That winter summer fuel thing should be added to the "great $8D" list. Along with some form of MAP switch (1, 2, 3 bar), or perhaps some melding of $58 and $8D would be in order.

The way to tell if the thing likely has winter fuel is probably just a starting ctemp running average temp as long as it's below typical max ambient temps. Maybe check for minimum start temp for the last X starts, and use that.

Or perhaps some FMU support in the $8D code.

I'll copy/paste this into that list.

 

I put the $58 code in the 730 ECM today. Also, installed a GM 2-bar map. Still have the 42 #/hr Ford injectors in it. Here is what I found:

1) using thirdgen.org to figure out the proper IAC pin-out is impossible. I searched and found four ways to wire the 730 ECM for the $58 code. I installed a base of a TB with the IAC so I could see what the IAC was actually doing.
It appears that the $58 has the coil bits "flipped" in the code when compared to the $8D code.

2) I can't find a BPC calculator so I used a value of 100 for the bpc vs. egr table. It is a 355 ci with 42 #/hr injectors. I still have to search and find the right equation. The 749 sticky post gives me a BPC value of 100398 which doesn't make sense.

3) The target idle showed to by 1250rpm using the 92-93 Typhoon .ads file I found. It was my first time logging with TunerPro so I didn't really know how to use it. The injector pulsewidths read as less than 1msec all the time including WOT.

4) The car has a fluctuating rpm below 1400rpm. It idled fine with the $8D code, so I don't see the injectors being a problem. The idle pulsewidths were 1.3msec with the $8D code and it idled very smooth. The $58 code makes it idle real bad.

5) Found a patch for installing the DIY-WB02 sensor but it uses the MAP2 input. I like the TPS2 input better so I have to change a few lines of code.

Anyone else get a target idle rpm stuck at 1250rpm on the ALDL stream and the car is actually trying to maintain 1250rpm?

Back to searching.

J

 

1.
$8D vs $58
E3-------------->E4 (IAC coil A high)
E4-------------->E3 (IAC coil A low)
E5-------------->E6 (IAC coil B high)
E6-------------->E5 (IAC coil B low)

2.
BPW vs EGR
The correct formula is: BPC = 730.75 * (vol of 1 cyl / inj flow in gms per sec)

BPC = 730.75 * (VOL / RATE)

; VOL = Vol of 1 Cylinder in liters
; RATE = Injector flow in gms/sec
;
; gms/sec = (lbs/hr / 3600) * 453.6

3.
You need to remove the 10k resistor on your aldl cable otherwised it is forced to idle at 1250rpm, this can be changed at 0x069E

4.
just tune it
A general thing is to remove some AE........... good luck.....

 

Thanks for the great info. I just came up with that stuff while searching at the same you where typing. I wish I had checked this thread a while ago. You would have saved me over an hours worth of searching.

I am going to stick with the IAC pin swap I did. I just brought up an old post about this if you want to check it out.

With the 355ci and 42#/hr it comes out to 100 for the bin. So I am good there.

The 1250rpm thing. Thanks, I didn't search for that yet. I will look into the code/parameter change. I never ran it without the 10K in there so I never noticed that it would have idled lower. I guess I over-scanned in this case.

I have probably about a month to get a partial tune before winter sets in. I read about removing some AE. I removed a little bit so far. It is an LT1 intake. I had to add AE with the $8D code so I didn't take much out of the $58 code. It is a new ECM for me so I do a little at a time.

Thanks again.
J

 

I have been working on removing some boost and I am going to start getting the idle better tomorrow. I noticed that right now that the async PWs are active sometimes on the ALDL log.

Anyone have a few pointers I could start with for tuning the $58 code idle?

 

As I now own 2 syty's, and seem to work on other peoples trucks I have done a fair amount of 58 tuning.

Dont even consider boost, don't get into boost, nothing YET. You will likely damage something.

First table to play with is idle. That needs to be good and very close. (F31E)

2nd table is your cruising stuff. Steady state. (F29).

Both of those tables do not include boost. Hence why I mentioned to not even worry about it.

Once you get Vacuum close in steady state, and it idle. Then you can play with AE a bit.

When all that is close you can play with boost. It is a multiplier table. So it multiplies the last value in the F29 table by a # in the F77 table. Really simple but works well. This is the 2nd reason I said not to worry about boost until this point. If you steady state vacuum stuff is not good, multipling is worthless.

After all that you can go back to AE, PE, DE cruise, etc and do a final tweak. You will end up going back and forth a bunch of times getting things right.

As weather changes you may find you need to access some of the Manifold temp correction tables, etc.

The $58 has a lot of good stuff in it, just takes time to learn it all.

 

The 42 #/hr injector have been a pain so far. Up top it revvs nice, but cruising has a surge of 100 rpms from 1about 1500 to 2500 rpm. I have the VE table to that the BLMs are 128+/-2

Idle is a nightmare. I could idle it smooth at 750rpm with the $8D code and 24#/hr injectors. With the 42#/hr and $58 code it flucuates real bad. I messed with the "min async pulse", "max async pulse", "min base PW". I lowered all of them. It idles a little better but still fluctuates.

* The ALDL injector pulsewidths don't make sense to me yet. * The idle pulsewidth in the ALDL report is 5.8msec to 6.3msec. Rather meaningless. The ALDL "async pulsewidth" is active every once in a while. The $8D and 24#/hrs had idle PWs of 1.7msec. So even if the $58 was firing the injectors every other inject event that it should still be around 2msec. It just doesn't make sense. I guess I have all winter to finish going through the $58 code to figure it out.
I lowered the min base PW to .5ms
I lowered the min async PW to .5ms
I lowered the max async PW to 3ms
I set the idle spark stabilizer to 0, 2, 4 degrees (pos & neg tbls)

Ended up setting the idle at 900rpm for now. It is at least drivable so that I can clean up the plugs after messing with the idle for a little while.

The ALDL spark values don't make sense. I put a "base ref angle" of 6 degress in the $58 bin. The ALDL reports that the timing is 16 degrees w/r/t TDC. It reports 22 degrees w/r/t to the distr. ref. pulse. Seems like the .ads file included with TunerPro 4.0 is backwards. I have to look at that. I have to modify it to show the IAT temp instead of the IAT A/D values.
I haven't figured out the 1-bar MAP reading in the ALDL yet. Need to look at the ALDL def. and .ads to figure out how to get the 2-bar MAP reading.

Back to reading the Sunbird doc and $58 assembly. Anyway, lots of things don't make sense so far. That is good, finally getting into the GM boost code.

 

The ALDL spark values are "Total SA-base ref angle" So if you have 6deg in base and SA table is 36deg the ALDL value should be 30deg. Get it?

The BPW at idle seems weird?

I have emailed you one of my recent $58bin's so that you can take a look if you want, if you want to try it its up to you.

/N.

 

Thanks, I'll take a look at the bin and compare to mine so see if something I did in mine is out of wack.

I understand what you wrote about the ALDL spark advance. I go by the lower ALDL SA and just add my 6 degrees to it. The SA comes out right that way.

 

I took a look at the bin you sent to get an idea of what I was doing wrong. I ended up changing the MIN PW HYSTERESIS value in mine my bin to match what you had. That was the only thing I changed in mine and it still idled bad.
I then set the min. temp for closed loop to 255 degrees C and started playing with the idle fuel table. After about 30 burns it idles good now at 750rpm. I could probably go lower, but I am happy with it for now. I need to play with the closed loop O2 thresholds to get it to idle good in closed loop.
In CL at idle it wants to jack the fuel up and run rich. It idles fine like that but is going to foul the plugs, waste fuel, and be stinky. Maybe it is finally time to make a DIY-WBO2 mod to the $58 code to run off of that instead of the NBO2. Wishfull thinking...still haven't finished my commented $58 code yet.

J

 

Oh yea, your server dumped my email
I'll PM you

 

42's absolutely suck to deal with. (ford green)

I've found when pw's go below 1.5mSec, the injectors are unstable at best. They may be firing, they may not be.

Although the $58 mask has code to deal with this, I'm not convinced it really works. I see it switch from quasi to async in the log, but still unstable.

Solution = set min PW, use tons of timing at idle, and deal with it.

Minor tuning issues show up on manual cars way more obviously than on automatic cars with mooshy torque converters.

-- Joe